The impact of social media interventions on eating behaviours and diet in adolescents and young adults: a mixed methods systematic review protocol

INTRODUCTION

Adolescents and young adults are susceptible population when it comes to healthy eating and dietary behaviours. The increasing use of social media by this age group presents a unique opportunity to promote healthy eating habits. Social media has become a popular platform for promoting health interventions, particularly among young people. However, there is a lack of consensus on the effectiveness of social media interventions in this population. This mixed-method systematic review aims to synthesise the available evidence on the impact of social media interventions on healthy eating behaviours among young people, their qualitative views and user experiences, and the intervention characteristics, behaviour change theories and techniques used to promote healthy eating.

METHODS AND ANALYSIS

We will conduct a comprehensive search of seven electronic databases, including ASSIA, Cochrane Library, Embase, MEDLINE, PsycINFO, Scopus and Web of Science. The search strategy will use a combination of Medical Subject Headings terms and keywords covering three domains: social media, eating behaviours and young people. The search will be limited to peer-reviewed published papers in any language, published from 2000. Three independent reviewers will screen studies based on predetermined eligibility criteria. Data will be extracted and analysed using a convergent segregated mixed-method approach. We will use random-effect meta-analysis or Synthesis Without Meta-analysis for quantitative data and thematic synthesis for qualitative data. Finally, narrative synthesis using concurrent triangulation will be used to bring together the results of the mixed-method data analysis to provide a comprehensive and integrated understanding of the impact and other features of social media interventions. This systematic review will adhere to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

ETHICS AND DISSEMINATION

Ethical approval is not required since this systematic review will not collect original data. The outcomes of this review will be shared through peer-reviewed publications and conference presentations and will contribute to the PhD thesis of the primary author.

PROSPERO REGISTRATION NUMBER

CRD42023414476.

The association between patterns of weight change, diabetes status and glycaemia among adults with overweight and obesity

AIMS

To investigate the associations between weight change patterns and 5-year incident non-diabetic hyperglycaemia (NDH), and glycated haemoglobin (HbA1c) levels among individuals who had overweight or obesity.

METHODS

This longitudinal cohort study (N = 435) pooled data from a weight management trial. Participants were adults with a body mass index of ≥28 kg/m2. They were categorised as "no weight loss", "maintainers", and "regainers" based on their weight at 3 months and 12 months after baseline. Multivariable logistic regression models and linear regressions were conducted to examine the associations.

RESULTS

Between 1-year and 5-year follow-ups, 77 participants developed NDH. We found no statistically significant association between weight change patterns and incident NDH at 5 years. Among weight loss maintainers, mean HbA1c was -0.15% (95% confidence intervals (CI): -0.22, -0.10) lower after 1 year and -0.15% (95% CI: -0.23, -0.06) lower after 5 years compared to the no weight loss group. There was no difference between weight loss regainers and no weight loss group in HbA1c levels.

CONCLUSIONS

Compared to those who did not lose weight, participants who maintained their weight loss had lower HbA1c levels after 1 year and 5 years, which highlights the importance of providing long-term support to prevent weight regain.

Experiences of emotional eating in an Acceptance and Commitment Therapy based weight management intervention (SWiM): A qualitative study

BACKGROUND

Emotional eating is a barrier to weight management. Interventions based on Acceptance and Commitment Therapy (ACT) promote the acceptance of uncomfortable feelings, which can reduce the urge to use food as a coping mechanism. We aimed to explore how participants of an ACT-based weight management intervention (WMI) experience emotional eating and relevant intervention content.

METHODS

We conducted semi-structured telephone interviews with participants of a digital ACT-based guided self-help WMI. Fifteen participants were purposefully selected to represent a range of demographic characteristics and emotional eating scores. We used reflexive thematic analysis to explore experiences of emotional eating.

RESULTS

We generated five themes. Participants improved emotional eating by disconnecting emotions from behaviours though increased self-awareness (theme 1) and by implementing alternative coping strategies, including preparation, substitution, and acceptance (theme 2). Most participants maintained improvements in emotional eating over time but wished for more opportunities to re-engage with intervention content, including more immediate support in triggering situations (theme 3). Participants who struggled to engage with emotional eating related intervention content often displayed an external locus of control over emotional eating triggers (theme 4). The perceived usefulness of the intervention depended on participants' prior experiences of emotional eating, and was thought insufficient for participants with complex emotional experiences (theme 5).

DISCUSSION

This ACT-based WMI helped participants with emotional eating by improving self-awareness and teaching alternative coping strategies. Intervention developers may consider adding ongoing forms of intervention that provide both real-time and long-term support. Additionally, a better understanding of how to support people with an external locus of control and people with complex experiences of emotional eating is needed. Future research may explore ways of personalising WMIs based on participants' emotional needs.

Dietary intervention in gestational diabetes: a qualitative study of the acceptability and feasibility of a novel whole-diet intervention in healthcare professionals

Gestational diabetes is treated with medical nutrition therapy, delivered by healthcare professionals; however, the optimal diet for affected women is unknown. Randomised controlled trials, such as the DiGest (Dietary Intervention in Gestational Diabetes) trial, will address this knowledge gap, but the acceptability of whole-diet interventions in pregnancy is unclear. Whole-diet approaches reduce bias but require high levels of participant commitment and long intervention periods to generate meaningful clinical outcomes. We aimed to assess healthcare professionals' views on the acceptability of the DiGest dietbox intervention for women with gestational diabetes and to identify any barriers to adherence which could be addressed to support good recruitment and retention to the DiGest trial. Female healthcare professionals (n 16) were randomly allocated to receive a DiGest dietbox containing 1200 or 2000 kcal/d including at least one weeks' food. A semi-structured interview was conducted to explore participants' experience of the intervention. Interviews were audio-recorded, transcribed verbatim and analysed thematically using NVivo software. Based on the findings of qualitative interviews, modifications were made to the dietboxes. Participants found the dietboxes convenient and enjoyed the variety and taste of the meals. Factors which facilitated adherence included participants having a good understanding of study aims and sufficient organisational skills to facilitate weekly meal planning in advance. Barriers to adherence included peer pressure during social occasions and feelings of deprivation or hunger (affecting both standard and reduced calorie groups). Healthcare professionals considered random allocation to a whole-diet replacement intervention to be acceptable and feasible in a clinical environment and offered benefits to participants including convenience.

The relationship of within-individual and between-individual variation in mental health with bodyweight: An exploratory longitudinal study

BACKGROUND

Poor mental health is associated with obesity, but existing studies are either cross-sectional or have long time periods between measurements of mental health and weight. It is, therefore, unclear how small fluctuations in mental wellbeing within individuals predict bodyweight over short time periods, e.g. within the next month. Studying this could identify modifiable determinants of weight changes and highlight opportunities for early intervention.

METHODS

2,133 UK adults from a population-based cohort completed monthly mental health and weight measurements using a mobile app over a period of 6-9 months. We used random intercept regression models to examine longitudinal associations of depressive symptoms, anxiety symptoms and stress with subsequent weight. In sub-group analyses, we included interaction terms of mental health variables with baseline characteristics. Mental health variables were split into "between-individual" measurements (= the participant's median score across all timepoints) and "within-individual" measurements (at each timepoint, the difference between the participant's current score and their median).

RESULTS

Within-individual variation in depressive symptoms predicted subsequent weight (0.045kg per unit of depressive symptom severity, 95% CI 0.021-0.069). We found evidence of a moderation effect of baseline BMI on the association between within-individual fluctuation in depressive symptoms and subsequent weight: The association was only apparent in those with overweight/obesity, and it was stronger in those with obesity than those with overweight (BMI<25kg/m2: 0.011kg per unit of depressive symptom severity [95% CI -0.017 to 0.039]; BMI 25-29.9kg/m2: 0.052kg per unit of depressive symptom severity [95%CI 0.010-0.094kg]; BMI≥30kg/m2: 0.071kg per unit of depressive symptom severity [95%CI 0.013-0.129kg]). We found no evidence for other interactions, associations of stress and anxiety with weight, or for a reverse direction of association.

CONCLUSION

In this exploratory study, individuals with overweight or obesity were more vulnerable to weight gain following higher-than-usual (for that individual) depressive symptoms than individuals with a BMI<25kg/m2.

A systematic review of ecological momentary assessment studies of appetite and affect in the experience of temptations and lapses during weight loss dieting

Dietary temptations and lapses challenge control over eating and act as barriers toward successful weight loss. These are difficult to assess in laboratory settings or with retrospective measures as they occur momentarily and driven by the current environment. A better understanding of how these experiences unfold within real-world dieting attempts could help inform strategies to increase the capacity to cope with the changes in appetitive and affective factors that surround these experiences. We performed a narrative synthesis on the empirical evidence of appetitive and affective outcomes measured using ecological momentary assessment (EMA) during dieting in individuals with obesity and their association with dietary temptations and lapses. A search of three databases (Scopus, Medline, and PsycInfo) identified 10 studies. Within-person changes in appetite and affect accompany temptations and lapses and are observable in the moments precipitating a lapse. Lapsing in response to these may be mediated through the strength of a temptation. Negative abstinence-violation effects occur following a lapse, which negatively impact self-attitudes. Engagement in coping strategies during temptations is effective for preventing lapses. These findings indicate that monitoring changes in sensations during dieting could help identify the crucial moments when coping strategies are most effective for aiding with dietary adherence.

Preventing type 2 diabetes: A research agenda for behavioural science

AIMS

The aim of this narrative review was to identify important knowledge gaps in behavioural science relating to type 2 diabetes prevention, to inform future research in the field.

METHODS

Seven researchers who have published behaviour science research applied to type 2 diabetes prevention independently identified several important gaps in knowledge. They met to discuss these and to generate recommendations to advance research in behavioural science of type 2 diabetes prevention.

RESULTS

A total of 21 overlapping recommendations for a research agenda were identified. These covered issues within the following broad categories: (a) evidencing the impact of whole population approaches to type 2 diabetes prevention, (b) understanding the utility of disease-specific approaches to type 2 diabetes prevention such as Diabetes Prevention Programmes (DPPs) compared to generic weight loss programmes, (c) identifying how best to increase reach and engagement of DPPs, whilst avoiding exacerbating inequalities, (d) the need to understand mechanism of DPPs, (e) the need to understand how to increase maintenance of changes as part of or following DPPs, (f) the need to assess the feasibility and effectiveness of alternative approaches to the typical self-regulation approaches that are most commonly used, and (g) the need to address emotional aspects of DPPs, to promote effectiveness and avoid harms.

CONCLUSIONS

There is a clear role for behavioural science in informing interventions to prevent people from developing type 2 diabetes, based on strong evidence of reach, effectiveness and cost-effectiveness. This review identifies key priorities for research needed to improve existing interventions.

Eating disorders in weight-related therapy (EDIT): Protocol for a systematic review with individual participant data meta-analysis of eating disorder risk in behavioural weight management

The Eating Disorders In weight-related Therapy (EDIT) Collaboration brings together data from randomised controlled trials of behavioural weight management interventions to identify individual participant risk factors and intervention strategies that contribute to eating disorder risk. We present a protocol for a systematic review and individual participant data (IPD) meta-analysis which aims to identify participants at risk of developing eating disorders, or related symptoms, during or after weight management interventions conducted in adolescents or adults with overweight or obesity. We systematically searched four databases up to March 2022 and clinical trials registries to May 2022 to identify randomised controlled trials of weight management interventions conducted in adolescents or adults with overweight or obesity that measured eating disorder risk at pre- and post-intervention or follow-up. Authors from eligible trials have been invited to share their deidentified IPD. Two IPD meta-analyses will be conducted. The first IPD meta-analysis aims to examine participant level factors associated with a change in eating disorder scores during and following a weight management intervention. To do this we will examine baseline variables that predict change in eating disorder risk within intervention arms. The second IPD meta-analysis aims to assess whether there are participant level factors that predict whether participation in an intervention is more or less likely than no intervention to lead to a change in eating disorder risk. To do this, we will examine if there are differences in predictors of eating disorder risk between intervention and no-treatment control arms. The primary outcome will be a standardised mean difference in global eating disorder score from baseline to immediately post-intervention and at 6- and 12- months follow-up. Identifying participant level risk factors predicting eating disorder risk will inform screening and monitoring protocols to allow early identification and intervention for those at risk.

Eating disorder risk during behavioral weight management in adults with overweight or obesity: A systematic review with meta-analysis

This systematic review examined change in eating disorder risk during weight management interventions. Four databases and clinical trials registries were searched in March and May 2022, respectively, to identify behavioral weight management intervention trials in adults with overweight/obesity measuring eating disorder symptoms at pre- and post-intervention or follow-up. Random effects meta-analyses were conducted examining within group change in risk. Of 12,023 screened, 49 were eligible (n = 6337, mean age range 22.1 to 59.9 years, mean (SD) 81(20.4)% female). Interventions ranged from 4 weeks to 18 months, with follow-up of 10 weeks to 36 months post-intervention. There was a within group reduction in global eating disorder scores (20 intervention arms; Hedges' g = -0.27; 95% CI -0.36, -0.17; I2 67.1%) and binge eating (49 intervention arms; -0.66; 95% CI -0.76, -0.56; I2 82.7%) post-intervention, both maintained at follow-up. Of 14 studies reporting prevalence or episodes of binge eating, all reported a reduction. Four studies reported eating disorder symptoms, not present at baseline, in a subset of participants (0%-6.5%). Overall, behavioral weight management interventions do not increase eating disorder symptoms for most adults; indeed, a modest reduction is seen post-intervention and follow-up. A small subset of participants may experience disordered eating; therefore, monitoring for the emergence of symptoms is important.

The need for future research into the assessment and monitoring of eating disorder risk in the context of obesity treatment

In adolescents and adults, the co-occurrence of eating disorders and overweight or obesity is continuing to increase, and the prevalence of eating disorders is higher in people with higher weight compared to those with lower weight. People with an eating disorder with higher weight are more likely to present for weight loss than for eating disorder treatment. However, there are no clinical practice guidelines on how to screen, assess, and monitor eating disorder risk in the context of obesity treatment. In this article, we first summarize current challenges and knowledge gaps related to the identification and assessment of eating disorder risk and symptoms in people with higher weight seeking obesity treatment. Specifically, we discuss considerations relating to the validation of current self-report measures, dietary restraint, body dissatisfaction, binge eating, and how change in eating disorder risk can be measured in this setting. Second, we propose avenues for further research to guide the development and implementation of clinical and research protocols for the identification and assessment of eating disorders in people with higher weight in the context of obesity treatment. PUBLIC SIGNIFICANCE: The number of people with both eating disorders and higher weight is increasing. Currently, there is little guidance for clinicians and researchers about how to identify and monitor risk of eating disorders in people with higher weight. We present limitations of current research and suggest future avenues for research to enhance care for people living with higher weight with eating disorders.

Eating Disorders In weight-related Therapy (EDIT) Collaboration: rationale and study design

The cornerstone of obesity treatment is behavioural weight management, resulting in significant improvements in cardio-metabolic and psychosocial health. However, there is ongoing concern that dietary interventions used for weight management may precipitate the development of eating disorders. Systematic reviews demonstrate that, while for most participants medically supervised obesity treatment improves risk scores related to eating disorders, a subset of people who undergo obesity treatment may have poor outcomes for eating disorders. This review summarises the background and rationale for the formation of the Eating Disorders In weight-related Therapy (EDIT) Collaboration. The EDIT Collaboration will explore the complex risk factor interactions that precede changes to eating disorder risk following weight management. In this review, we also outline the programme of work and design of studies for the EDIT Collaboration, including expected knowledge gains. The EDIT studies explore risk factors and the interactions between them using individual-level data from international weight management trials. Combining all available data on eating disorder risk from weight management trials will allow sufficient sample size to interrogate our hypothesis: that individuals undertaking weight management interventions will vary in their eating disorder risk profile, on the basis of personal characteristics and intervention strategies available to them. The collaboration includes the integration of health consumers in project development and translation. An important knowledge gain from this project is a comprehensive understanding of the impact of weight management interventions on eating disorder risk.

Supporting Weight Management during COVID-19 (SWiM-C): twelve-month follow-up of a randomised controlled trial of a web-based, ACT-based, guided self-help intervention

OBJECTIVES

We developed a guided self-help intervention (Supporting Weight Management during COVID-19, "SWiM-C") to support adults with overweight or obesity in their weight management during the COVID-19 pandemic. This parallel, two-group trial (ISRCTN12107048) evaluated the effect of SWiM-C on weight and determinants of weight management over twelve months.

METHODS

Participants (≥18 years, body-mass-index ≥25 kg/m²) were randomised to the SWiM-C intervention or to a standard advice group (unblinded). Participants completed online questionnaires at baseline, four months, and twelve months. The primary outcome was change in self-reported weight from baseline to twelve months; secondary outcomes were eating behaviour (uncontrolled eating, emotional eating, cognitive restraint of food intake), experiential avoidance, depression, anxiety, stress, wellbeing and physical activity.

INTERVENTIONS

SWiM-C is based on acceptance and commitment therapy (ACT). Participants had access to an online web platform with 12 weekly modules and email and telephone contact with a trained, non-specialist coach. Standard advice was a leaflet on managing weight and mood during the COVID-19 pandemic.

RESULTS

388 participants were randomised (SWiM-C: n = 192, standard advice: n = 196). The baseline-adjusted difference in weight change between SWiM-C (n = 119) and standard advice (n = 147) was -0.81 kg (95% CI: -2.24 to 0.61 kg). SWiM-C participants reported a reduction in experiential avoidance (-2.45 [scale:10-70], 95% CI: -4.75 to -0.15), uncontrolled eating (-3.36 [scale: 0-100], 95% CI: -5.66 to -1.06), and emotional eating (-4.14 [scale:0-100], 95% CI: -7.25 to -1.02) and an increase in physical activity (8.96 [MET-min/week], 95% CI: 0.29 to 17.62) compared to standard advice participants. We found no evidence of an effect on remaining outcomes. No adverse events/side effects were reported.

CONCLUSIONS

Whilst we were unable to conclude that the intervention had an effect on weight, SWiM-C improved eating behaviours, experiential avoidance and physical activity. Further refinement of the intervention is necessary to ensure meaningful effects on weight prior to implementation in practice.

TRIAL REGISTRATION NUMBER

ISRCTN 12107048.

Association between Indicators of Inequality and Weight Change following a Behavioural Weight Loss Intervention

INTRODUCTION

Weight loss through behavioural weight management interventions can have important health benefits for people with obesity. However, to maximise the health benefits, weight loss must be maintained. Evidence suggests that behavioural weight loss interventions do not exacerbate inequalities in the short term. However, no study has yet considered whether inequalities exist in long-term weight change following intervention. We aimed to investigate if there are inequalities in weight change following weight loss intervention.

METHODS

We conducted a cohort analysis of data from the Weight Loss Referrals for Adults in Primary Care (WRAP) trial (N = 1,267). WRAP randomised participants to receive a brief intervention information booklet or vouchers for 12-weeks or 52-weeks of WW (formerly WeightWatchers) and followed them for 5 years. Multiple linear regression estimated the association between exposures (indicators of inequality) and outcomes (change in weight between 1- and 5-years). Each model was adjusted for the intervention group, baseline weight, weight change between baseline and 1-year, research centre, and source of the 5-year weight data.

RESULTS

Of the 1,267 participants in WRAP, 708 had weight change data available. Mean weight change between 1- and 5-years was +3.30 kg (SD 9.10 kg). A 1 year difference in age at baseline was associated with weight change of 0.11 kg ((95% CI 0.06, 0.16), p < 0.001). We did not find evidence of associations between ethnicity, gender, education, indices of multiple deprivation, household income, or other family members participating in a weight loss programme and weight change.

CONCLUSION

Except for age, we did not find evidence of inequalities in weight change following a behavioural intervention. Findings further support the use of behavioural weight management interventions as part of a systems-wide approach to improving population health.

Participants' experiences of mental health during a COVID-19 tailored ACT-based behavioural weight management intervention: a qualitative study

PURPOSE

We aimed to explore participants' experiences of mental health during an acceptance and commitment therapy (ACT)-based guided self-help intervention to support weight management in adults with overweight or obesity during the COVID-19 pandemic (SWiM-C: Supporting Weight Management during COVID-19).

METHODS

We conducted semi-structured telephone interviews with twenty participants and used reflexive thematic analysis to identify patterns of meaning across the dataset relevant to mental health.

RESULTS

Four themes were conceptualized: i) Mental health changes associated with SWiM-C, ii) External factors negatively impacted mental health and intervention engagement, iii) Use and impact of coping responses, and iv) Intervention preferences based on psychological needs.

CONCLUSIONS

Findings suggest that participants were exposed to multiple factors, both related to and external to the intervention, that negatively impact their mental health, yet ACT-based aspects of the SWiM-C intervention appeared to support participants to adaptively manage the decline in their mental health. The findings can be used to inform the development of future weight management interventions, such as through intervention personalization and the inclusion of more strategies that target emotional regulation.Trial registration: ISRCTN 12107048, https://www.isrctn.com/ISRCTN12107048.

Long-term impact of a behavioral weight management program on depression and anxiety symptoms: 5-year follow-up of the WRAP trial

OBJECTIVE

Behavioral weight management programs may support short-term mental health; however, limited evidence reports the long-term impacts. This study investigated the impact of behavioral weight management programs on depression and anxiety symptoms at 5 years from baseline.

METHODS

The Weight loss Referrals for Adults in Primary care (WRAP) trial randomized 1267 adults with BMI ≥ 28 kg/m² to a brief intervention (BI) or commercial behavioral weight management program (WW; formerly Weight Watchers) for 12 or 52 weeks (CP12 and CP52, respectively). Linear regression was used to separately compare 5-year changes in depression and anxiety symptoms (by Hospital Anxiety and Depression Scale) between randomized groups, adjusting for baseline depression/anxiety symptoms, gender, and research center.

RESULTS

A total of 643 (51%) participants attended the 5-year study follow-up visit. There was no evidence of a difference between the randomized groups for 5-year changes in depression (BI: -0.08 ± 3.29; CP12: 0.02 ± 3.01; CP52: -0.09 ± 3.41) or anxiety (BI: 0.16 ± 3.50; CP12: -0.05 ± 3.55; CP52: -0.66 ± 3.59) symptoms.

CONCLUSIONS

This study found no evidence that commercial weight management programs differed in 5-year changes in depression and anxiety symptoms, compared with BI. These are average effects; some individuals experienced increases or decreases in symptoms. Future research should investigate who is at most risk of mental health declines and investigate how to support them. Future trials should transparently report long-term mental health outcomes to strengthen understanding.

Effectiveness and cost-effectiveness of referral to a commercial open group behavioural weight management programme in adults with overweight and obesity: 5-year follow-up of the WRAP randomised controlled trial

BACKGROUND

There is evidence that commercially available behavioural weight management programmes can lead to short-term weight loss and reductions in glycaemia. Here, we aimed to provide the 5-year impact and cost-effectiveness of these interventions compared with a brief intervention.

METHODS

WRAP was a non-blinded, parallel-group randomised controlled trial (RCT). We recruited from primary care practices in England and randomly assigned participants to one of three interventions (brief intervention, 12-week open-group behavioural programme [WW, formerly Weight Watchers], or a 52-week open-group WW behavioural programme) in an uneven (2:5:5) allocation. Participants were followed up 5 years after randomisation using data from measurement visits at primary care practices or a research centre, review of primary care electronic medical notes, and self-report questionnaires. The primary outcome was change in weight at 5 years follow-up, assessed using analysis of covariance. We also estimated cost-effectiveness of the intervention. This study is registered at Current Controlled Trials, ISRCTN64986150.

FINDINGS

Between Oct 18, 2012, and Feb 10, 2014, we recruited 1269 eligible participants (two participants were randomly assigned but not eligible and therefore excluded) and 1040 (82%) consented to be approached about additional follow-up and to have their medical notes reviewed at 5 years. The primary outcome (weight) was ascertained for 871 (69%) of 1267 eligible participants. Mean duration of follow-up was 5·1 (SD 0·3) years. Mean weight change from baseline to 5 years was -0·46 (SD 8·31) kg in the brief intervention group, -1·95 (9·55) kg in the 12-week programme group, and -2·67 (9·81) kg in the 52-week programme. The adjusted difference in weight change was -1·76 (95% CI -3·68 to 0·17) kg between the 52-week programme and the brief intervention; -0·80 (-2·13 to 0·54) kg between the 52-week and the 12-week programme; and -0·96 (-2·90 to 0·97) kg between the 12-week programme and the brief intervention. During the trial, the 12-week programme incurred the lowest cost and produced the highest quality-adjusted life-years (QALY). Simulations beyond 5 years suggested that the 52-week programme would deliver the highest QALYs at the lowest cost and would be the most cost-effective. No participants reported adverse events related to the intervention.

INTERPRETATION

Although the difference in weight change between groups was not statistically significant, some weight loss was maintained at 5 years after an open-group behavioural weight management programme. Health economic modelling suggests that this could have important implications to reduce the incidence of weight-related disease and these interventions might be cost-saving.

FUNDING

The UK National Institute for Health and Care Research Programme Grants for Applied Research and the Medical Research Council.

Effectiveness and cost-effectiveness of referral to a commercial open group behavioural weight management programme in adults with overweight and obesity: 5-year follow-up of the WRAP randomised controlled trial

BACKGROUND

There is evidence that commercially available behavioural weight management programmes can lead to short-term weight loss and reductions in glycaemia. Here, we aimed to provide the 5-year impact and cost-effectiveness of these interventions compared with a brief intervention.

METHODS

WRAP was a non-blinded, parallel-group randomised controlled trial (RCT). We recruited from primary care practices in England and randomly assigned participants to one of three interventions (brief intervention, 12-week open-group behavioural programme [WW, formerly Weight Watchers], or a 52-week open-group WW behavioural programme) in an uneven (2:5:5) allocation. Participants were followed up 5 years after randomisation using data from measurement visits at primary care practices or a research centre, review of primary care electronic medical notes, and self-report questionnaires. The primary outcome was change in weight at 5 years follow-up, assessed using analysis of covariance. We also estimated cost-effectiveness of the intervention. This study is registered at Current Controlled Trials, ISRCTN64986150.

FINDINGS

Between Oct 18, 2012, and Feb 10, 2014, we recruited 1269 eligible participants (two participants were randomly assigned but not eligible and therefore excluded) and 1040 (82%) consented to be approached about additional follow-up and to have their medical notes reviewed at 5 years. The primary outcome (weight) was ascertained for 871 (69%) of 1267 eligible participants. Mean duration of follow-up was 5·1 (SD 0·3) years. Mean weight change from baseline to 5 years was -0·46 (SD 8·31) kg in the brief intervention group, -1·95 (9·55) kg in the 12-week programme group, and -2·67 (9·81) kg in the 52-week programme. The adjusted difference in weight change was -1·76 (95% CI -3·68 to 0·17) kg between the 52-week programme and the brief intervention; -0·80 (-2·13 to 0·54) kg between the 52-week and the 12-week programme; and -0·96 (-2·90 to 0·97) kg between the 12-week programme and the brief intervention. During the trial, the 12-week programme incurred the lowest cost and produced the highest quality-adjusted life-years (QALY). Simulations beyond 5 years suggested that the 52-week programme would deliver the highest QALYs at the lowest cost and would be the most cost-effective. No participants reported adverse events related to the intervention.

INTERPRETATION

Although the difference in weight change between groups was not statistically significant, some weight loss was maintained at 5 years after an open-group behavioural weight management programme. Health economic modelling suggests that this could have important implications to reduce the incidence of weight-related disease and these interventions might be cost-saving.

FUNDING

The UK National Institute for Health and Care Research Programme Grants for Applied Research and the Medical Research Council.

A systematic review of inequalities in the uptake of, adherence to, and effectiveness of behavioral weight management interventions in adults

The extent to which behavioral weight management interventions affect health inequalities is uncertain, as is whether trials of these interventions directly consider inequalities. We conducted a systematic review, synthesizing evidence on how different aspects of inequality impact uptake, adherence, and effectiveness in trials of behavioral weight management interventions. We included (cluster-) randomized controlled trials of primary care-applicable behavioral weight management interventions in adults with overweight or obesity published prior to March 2020. Data about trial uptake, intervention adherence, attrition, and weight change by PROGRESS-Plus criteria (place of residence, race/ethnicity, occupation, gender, religion, education, socioeconomic status, social capital, plus other discriminating factors) were extracted. Data were synthesized narratively and summarized in harvest plots. We identified 91 behavioral weight loss interventions and 12 behavioral weight loss maintenance interventions. Fifty-six of the 103 trials considered inequalities in relation to at least one of intervention or trial uptake (n = 15), intervention adherence (n = 15), trial attrition (n = 32), or weight outcome (n = 34). Most trials found no inequalities gradient. If a gradient was observed for trial uptake, intervention adherence, and trial attrition, those considered "more advantaged" did best. Alternative methods of data synthesis that enable data to be pooled and increase statistical power may enhance understanding of inequalities in behavioral weight management interventions.

Acceptability and feasibility of an acceptance and commitment therapy-based guided self-help intervention for weight loss maintenance in adults who have previously completed a behavioural weight loss programme: the SWiM feasibility study protocol

INTRODUCTION

The cost-effectiveness and long-term health impact of behavioural weight management programmes depends on post-treatment weight-loss maintenance. Growing evidence suggests that interventions using acceptance and commitment therapy (ACT) could improve long-term weight management. We developed an ACT-based, guided self-help intervention to support adults who have recently completed a behavioural weight loss programme. This study will assess the feasibility and acceptability of this type of intervention and findings will inform the development of a full-scale trial.

METHODS AND ANALYSIS

This is a pragmatic, randomised, single-blind, parallel group, two-arm, feasibility study with an embedded process evaluation. We will recruit and randomise 60 adults who have recently completed a behavioural weight loss programme to the ACT-based intervention or standard care, using a computer-generated sequence with 2:1 allocation stratified by diabetes status and sex. Baseline and 6-month measurements will be completed using online questionnaires. Qualitative interviews will be conducted with a subsample of participants and coaches about their experiences at 3 (mid-intervention) and 6 (postintervention) months. Feasibility and acceptability of the intervention, and a full-scale trial will be assessed using a number of outcomes, including adherence to, and engagement with the intervention, recruitment and retention rates, proportion of missing data for each outcome measure, participants' experiences of the intervention and study, and coaches' experiences of delivering intervention support. Quantitative and qualitative findings will be integrated and summarised to contribute to the interpretation of the main feasibility evaluation findings. Value of information methods will be used to estimate the decision uncertainty associated with the intervention's cost-effectiveness and determine the value of a definitive trial.

ETHICS AND DISSEMINATION

Ethical approval was received from Cambridge South Research Ethics Committee on 15/03/2021 (21/EE/0024). This protocol (V.2) was approved on 19 April 2021. Findings will be published in peer-reviewed scientific journals and communicated to other stakeholders as appropriate.

TRIAL REGISTRATION NUMBER

ISRCTN12685964.

Association between weight change and incidence of cardiovascular disease events and mortality among adults with type 2 diabetes: a systematic review of observational studies and behavioural intervention trials

AIMS/HYPOTHESIS

Weight loss is often recommended in the treatment of type 2 diabetes. While evidence has shown that large weight loss may lead to diabetes remission and improvement in cardiovascular risk factors, long-term impacts are unclear. We performed a systematic review of studies of weight loss and other weight changes and incidence of CVD among people with type 2 diabetes.

METHODS

Observational studies of behavioural (non-surgical and non-pharmaceutical) weight changes and CVD events among adults with type 2 diabetes, and trials of behavioural interventions targeting weight loss, were identified through searches of MEDLINE, EMBASE, Web of Science, CINAHL, and The Cochrane Library (CENTRAL) until 9 July 2019. Included studies reported change in weight and CVD and/or mortality outcomes among adults with type 2 diabetes. We performed a narrative synthesis of observational studies and meta-analysis of trial data.

RESULTS

Of 13,227 identified articles, 17 (14 observational studies, three trials) met inclusion criteria. Weight gain (vs no change) was associated with higher hazard of CVD events (HRs [95% CIs] ranged from 1.13 [1.00, 1.29] to 1.63 [1.11, 2.39]) and all-cause mortality (HRs [95% CIs] ranged from 1.26 [1.12, 1.41] to 1.57 [1.33, 1.85]). Unintentional weight loss (vs no change) was associated with higher risks of all-cause mortality, but associations with intentional weight loss were unclear. Behavioural interventions targeting weight loss showed no effect on CVD events (pooled HR [95% CI] 0.95 [0.71, 1.27]; I² = 50.1%). Risk of bias was moderate in most studies and was high in three studies, due to potential uncontrolled confounding and method of weight assessment.

CONCLUSIONS/INTERPRETATION

Weight gain is associated with increased risks of CVD and mortality, although there is a lack of data supporting behavioural weight-loss interventions for CVD prevention among adults with type 2 diabetes. Long-term follow-up of behavioural intervention studies is needed to understand effects on CVD and mortality and to inform policy concerning weight management advice and support for people with diabetes. PROSPERO registration CRD42019127304.

Using health economic modelling to inform the design and development of an intervention: estimating the justifiable cost of weight loss maintenance in the UK

BACKGROUND

There is a need to develop cost-effective weight loss maintenance interventions to prolong the positive impact of weight loss on health outcomes. Conducting pre-trial health economic modelling is recommended to inform the design and development of behavioural interventions. We aimed to use health economic modelling to estimate the maximum cost per-person (justifiable cost) of a cost-effective behavioural weight loss maintenance intervention, given an estimated intervention effect for individuals with: i) a Body Mass Index (BMI) of 28 kg/m2 or above without diabetes and ii) a diagnosis of type 2 diabetes prescribed a single non-insulin diabetes medication.

METHODS

The School for Public Health Research Diabetes prevention model was used to estimate the lifetime Quality-adjusted life year (QALY) gains, healthcare costs, and maximum justifiable cost associated with a weight loss maintenance intervention. Based on a meta-analysis, the estimated effect of a weight loss maintenance intervention following a 9 kg weight loss, was a regain of 1.33 kg and 4.38 kg in years one and two respectively compared to greater regain of 2.84 kg and 5.6 kg in the control group. Sensitivity analysis was conducted around the rate of regain, duration of effect and initial weight loss.

RESULTS

The justifiable cost for a weight loss maintenance intervention at an ICER of £20,000 per QALY was £104.64 for an individual with a BMI of 28 or over and £88.14 for an individual with type 2 diabetes. Within sensitivity analysis, this varied from £36.42 to £203.77 for the former, and between £29.98 and £173.05 for the latter.

CONCLUSIONS

Researchers developing a weight loss maintenance intervention should consider these maximum justifiable cost estimates and the potential impact of the duration of effect and initial weight loss when designing intervention content and deciding target populations. Future research should consider using the methods demonstrated in this study to use health economic modelling to inform the design and budgetary decisions in the development of a behavioural interventions.

Association between patient activation, self-management behaviours and clinical outcomes in adults with diabetes or related metabolic disorders: a systematic review and meta-analysis protocol

INTRODUCTION

Diabetes and related metabolic disorders such as obesity and cardiovascular diseases (CVD) are a growing global issue. Equipping individuals with the necessary 'knowledge, skills and confidence to self-manage their health' (ie, patient activation (PAct)) may lead to improvements in health outcomes. It is unclear whether existing evidence allows us to assume a causal relationship. We aim to synthesise and critically appraise evidence on the relationship between PAct and self-management behaviours and clinical outcomes of people living with diabetes and related metabolic disorders.

METHODS AND ANALYSIS

The protocol is based on guidance on Preferred Reporting Items for Systematic Review and Meta-analysis Protocols. We will search Medline, Embase, CENTRAL, PsycInfo, Web of Science and CINAHL using search terms related to PAct, diabetes, pre-diabetes, obesity and CVD. Any quantitative study design is eligible provided studies assess the association between PAct and clinical outcomes and/or self-management behaviours of diabetes and related metabolic disorders. Outcomes include behavioural (eg, diet) and clinical (eg, blood pressure) outcomes. Two reviewers will independently screen titles/abstracts and full texts and assess risk of bias using the revised Cochrane risk-of-bias tool for randomised trials or the Risk of Bias Assessment Tool for Nonrandomised Studies (RoBANS).One reviewer will extract data, with independent checking by a second reviewer. We will critically assess the level of evidence available for assuming a causal association between PAct and outcomes. Data permitting, we will use the Hunter-Schmidt random-effects method to meta-analyse correlations across studies.

ETHICS AND DISSEMINATION

Ethical approval is not required. The review will be disseminated in the form of a peer-reviewed journal article, at conferences and other presentations. The findings of the review will be of interest to clinical commissioning groups, policymakers and intervention deliverers/developers.

PROSPERO REGISTRATION NUMBER

CRD42021230727.

Development of a Web-Based, Guided Self-help, Acceptance and Commitment Therapy-Based Intervention for Weight Loss Maintenance: Evidence-, Theory-, and Person-Based Approach

Background

The long-term impact and cost-effectiveness of weight management programs depend on posttreatment weight maintenance. There is growing evidence that interventions based on third-wave cognitive behavioral therapy, particularly acceptance and commitment therapy (ACT), could improve long-term weight management; however, these interventions are typically delivered face-to-face by psychologists, which limits the scalability of these types of intervention.

Objective

The aim of this study is to use an evidence-, theory-, and person-based approach to develop an ACT-based intervention for weight loss maintenance that uses digital technology and nonspecialist guidance to minimize the resources needed for delivery at scale.

Methods

Intervention development was guided by the Medical Research Council framework for the development of complex interventions in health care, Intervention Mapping Protocol, and a person-based approach for enhancing the acceptability and feasibility of interventions. Work was conducted in two phases: phase 1 consisted of collating and analyzing existing and new primary evidence and phase 2 consisted of theoretical modeling and intervention development. Phase 1 included a synthesis of existing evidence on weight loss maintenance from previous research, a systematic review and network meta-analysis of third-wave cognitive behavioral therapy interventions for weight management, a qualitative interview study of experiences of weight loss maintenance, and the modeling of a justifiable cost for a weight loss maintenance program. Phase 2 included the iterative development of guiding principles, a logic model, and the intervention design and content. Target user and stakeholder panels were established to inform each phase of development, and user testing of successive iterations of the prototype intervention was conducted.

Results

This process resulted in a guided self-help ACT-based intervention called SWiM (Supporting Weight Management). SWiM is a 4-month program consisting of weekly web-based sessions for 13 consecutive weeks followed by a 4-week break for participants to reflect and practice their new skills and a final session at week 18. Each session consists of psychoeducational content, reflective exercises, and behavioral experiments. SWiM includes specific sessions on key determinants of weight loss maintenance, including developing skills to manage high-risk situations for lapses, creating new helpful habits, breaking old unhelpful habits, and learning to manage interpersonal relationships and their impact on weight management. A trained, nonspecialist coach provides guidance for the participants through the program with 4 scheduled 30-minute telephone calls and 3 further optional calls.

Conclusions

This comprehensive approach facilitated the development of an intervention that is based on scientific theory and evidence for supporting people with weight loss maintenance and is grounded in the experiences of the target users and the context in which it is intended to be delivered. The intervention will be refined based on the findings of a planned pilot randomized controlled trial.

Supporting Weight Management during COVID-19: A Randomized Controlled Trial of a Web-Based, ACT-Based, Guided Self-Help Intervention

INTRODUCTION

Adults with overweight and obesity are vulnerable to weight gain and mental health deterioration during the COVID-19 pandemic. We developed a web-based, guided self-help intervention based on Acceptance and Commitment Therapy (ACT) that aims to support adults with overweight and obesity to prevent weight gain by helping them to manage their eating behaviours, be more physically active, and protect their emotional wellbeing ("SWiM-C"). SWiM-C is a guided self-help programme using non-specialist guides to enhance scalability and population reach while minimizing cost. This study evaluated the effect of SWiM-C on bodyweight, eating behaviour, physical activity, and mental wellbeing in adults with overweight and obesity over 4 months during the COVID-19 pandemic in the UK.

METHODS

We randomized adults (BMI ≥25 kg/m2) to SWiM-C or to a wait-list standard advice group. Participants completed outcome assessments online at baseline and 4 months. The primary outcome was self-measured weight; secondary outcomes were eating behaviour, physical activity, experiential avoidance/psychological flexibility, depression, anxiety, stress, and wellbeing. We estimated differences between study groups in change in outcomes from baseline to 4 months using linear regression, adjusted for outcome at baseline and the randomization stratifiers (BMI, sex). The trial was pre-registered (ISRCTN12107048).

RESULTS

486 participants were assessed for eligibility; 388 participants were randomized (196 standard advice, 192 SWiM-C), and 324 were analysed. The adjusted difference in weight between SWiM-C and standard advice was -0.60 kg (-1.67 to 0.47, p = 0.27). SWiM-C led to improvements in uncontrolled eating (-3.61 [-5.94 to -1.28]), cognitive restraint (5.28 [2.81-7.75]), experiential avoidance (-3.39 [-5.55 to -1.23]), and wellbeing (0.13 [0.07-0.18]).

CONCLUSIONS

SWiM-C improved several psychological determinants of successful weight management and had a protective effect on wellbeing during the pandemic. However, differences in weight and some other outcomes were compatible with no effect of the intervention, suggesting further refinement of the intervention is needed.

Participant Characteristics Associated with Changes in Mental Health in a Trial of Behavioural Weight Management Programmes: Secondary Analysis of the WRAP Trial

INTRODUCTION

On average, aspects of mental health improve following behavioural weight management programmes, yet this is not the case for all participants. It is important to identify those at risk of harm to provide more effective psychological support. We aimed to identify participant characteristics associated with changes in depression and anxiety in participants of a behavioural weight management programme.

METHODS

In the Weight loss Referrals for Adults in Primary care trial, 1,267 adults with body mass index ≥28 kg/m2 were randomized to brief intervention, or WW (formerly weight watchers) for 12-weeks or 52-weeks and followed for 5 years. We used linear and multinomial regression to explore the association between participant characteristics and changes in depression and anxiety (measured by the hospital anxiety and depression scale). Where possible, the impact of missing data was investigated using multiple imputation.

RESULTS

Higher baseline anxiety was associated with decreases in anxiety symptoms and increases in depression symptoms from baseline to follow-up. Higher baseline depression was associated with decreases in depression symptoms and increases in anxiety symptoms from baseline to follow-up. The magnitude of the associations was small. No further characteristics were consistently associated with changes in mental health.

DISCUSSION

Evidence suggests that baseline depression and anxiety may indicate how depression and anxiety symptoms change during and after attending WW. Measurement of depression and anxiety at the start of a behavioural weight management programme and subsequent monitoring may facilitate timely psychological support if a deterioration in mental health is identified. Further research in large and diverse participant samples is required to clarify the findings.

The impact of participant mental health on attendance and engagement in a trial of behavioural weight management programmes: secondary analysis of the WRAP randomised controlled trial

Background

Low attendance and engagement in behavioural weight management trials are common. Mental health may play an important role, however previous research exploring this association is limited with inconsistent findings. We aimed to investigate whether mental health was associated with attendance and engagement in a trial of behavioural weight management programmes.

Methods

This is a secondary data analysis of the Weight loss referrals for adults in primary care (WRAP) trial, which randomised 1267 adults with overweight or obesity to brief intervention, WW (formerly Weight Watchers) for 12-weeks, or WW for 52-weeks. We used regression analyses to assess the association of baseline mental health (depression and anxiety (by Hospital Anxiety and Depression Scale), quality of life (by EQ5D), satisfaction with life (by Satisfaction with Life Questionnaire)) with programme attendance and engagement in WW groups, and trial attendance in all randomised groups.

Results

Every one unit of baseline depression score was associated with a 1% relative reduction in rate of WW session attendance in the first 12 weeks (Incidence rate ratio [IRR] 0.99; 95% CI 0.98, 0.999). Higher baseline anxiety was associated with 4% lower odds to report high engagement with WW digital tools (Odds ratio [OR] 0.96; 95% CI 0.94, 0.99). Every one unit of global quality of life was associated with 69% lower odds of reporting high engagement with the WW mobile app (OR 0.31; 95% CI 0.15, 0.64). Greater symptoms of depression and anxiety and lower satisfaction with life at baseline were consistently associated with lower odds of attending study visits at 3-, 12-, 24-, and 60-months.

Conclusions

Participants were less likely to attend programme sessions, engage with resources, and attend study assessments when reporting poorer baseline mental health. Differences in attendance and engagement were small, however changes may still have a meaningful effect on programme effectiveness and trial completion. Future research should investigate strategies to maximise attendance and engagement in those reporting poorer mental health.

Trial registration

The original trial (ISRCTN82857232) and five year follow up (ISRCTN64986150) were prospectively registered with Current Controlled Trials on 15/10/2012 and 01/02/2018.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-021-01216-6.

Modification of cardiovascular disease risk by health behaviour change following type 2 diabetes diagnosis

AIMS

Among adults with type 2 diabetes (T2D), unhealthy behaviours are associated with increased risk of cardiovascular disease (CVD) events. To date, little research has considered whether healthy changes in behaviours following T2D diagnosis reduce CVD risk.

METHODS

A cohort of 867 adults with screen-detected T2D, participating in the Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen-Detected Diabetes in Primary Care (ADDITION)-Cambridge trial, were followed for 10 years for incidence of CVD events. Diet, alcohol consumption, moderate/vigorous physical activity and smoking were assessed by questionnaire at the time of T2D screening and 1 year later. We estimated associations between health behaviours and CVD using Cox regression. We assessed modification of the associations by behaviour change in the year following T2D diagnosis.

RESULTS

Smoking [hazard ratio (HR): 1.73 (95% CI: 1.04, 2.87)] and high fat intake [HR: 1.70 (95% CI: 1.02, 2.85)] were associated with a higher hazard of CVD, while high plasma vitamin C [HR: 0.44 (95% CI: 0.22, 0.87)] and high fibre intake [HR: 0.60 (95% CI: 0.36, 0.99)] were associated with a lower hazard of CVD. Reduction in fat intake following T2D diagnosis modified associations with CVD. In particular, among those with the highest fat intake, decreasing intake attenuated the association with CVD [HR: 0.75 (95% CI: 0.36, 1.56)].

CONCLUSION

Following T2D diagnosis, decreasing fat intake was associated with lower long-term CVD risk. This evidence may raise concerns about low-carbohydrate, high-fat diets to achieve weight loss following T2D diagnosis. Further research considering the sources of fat is needed to inform dietary recommendations.

TRIAL REGISTRATION

This trial is registered as ISRCTN86769081. Retrospectively registered on 15 December 2006.

Changing the narrative around obesity in the UK: a survey of people with obesity and healthcare professionals from the ACTION-IO study

OBJECTIVES

To investigate the perceptions, attitudes, behaviours and potential barriers to effective obesity care in the UK using data collected from people with obesity (PwO) and healthcare professionals (HCPs) in the Awareness, Care, and Treatment In Obesity maNagement-International Observation (ACTION-IO) study.

DESIGN

UK's PwO (body mass index of ≥30 kg/m² based on self-reported height and weight) and HCPs who manage patients with obesity completed an online survey.

RESULTS

In the UK, 1500 PwO and 306 HCPs completed the survey. Among the 47% of PwO who discussed weight with an HCP in the past 5 years, it took a mean of 9 years from the start of their struggles with weight until a discussion occurred. HCPs reported that PwO initiated 35% of weight-related discussions; PwO reported that they initiated 47% of discussions. Most PwO (85%) assumed full responsibility for their own weight loss. The presence of obesity-related comorbidities was cited by 76% of HCPs as a top criterion for initiating weight management conversations. The perception of lack of interest (72%) and motivation (61%) in losing weight was reported as top reasons by HCPs for not discussing weight with a patient. Sixty-five per cent of PwO liked their HCP bringing up weight during appointments. PwO reported complex and varied emotions following a weight loss conversation with an HCP, including supported (36%), hopeful (31%), motivated (23%) and embarrassed (17%). Follow-up appointments were scheduled for 19% of PwO after a weight discussion despite 62% wanting follow-up.

CONCLUSIONS

The current narrative around obesity requires a paradigm shift in the UK to address the delay between PwO struggling with their weight and discussing weight with their HCP. Perceptions of lack of patient interest and motivation in weight management must be challenged along with the blame culture of individual responsibility that is prevalent throughout society. While PwO may welcome weight-related conversations with an HCP, they evoke complex feelings, demonstrating the need for sensitivity and respect in these conversations.

TRIAL REGISTRATION NUMBER

NCT03584191.

Associations between hedonic hunger and BMI during a two-year behavioural weight loss trial

Objective

Prospective studies on relationships between hedonic hunger and BMI (Body Mass Index) during weight management are lacking. This study examined if hedonic hunger reduced during a behavioural weight management programme, and if hedonic hunger predicted future BMI.

Methods

Participants were 594 community-dwelling, UK-based adults(396 female; age 56.43 years, s.d. = 12.50, range 20–83 years); 490 participants (82.5%) had obesity. Participants were randomised to a 12- or 52-week behavioural weight management intervention (WW12 or WW52, respectively) or a brief self-help intervention (BI). Relationships between hedonic hunger and BMI over 24 months (baseline, 3, 12, 24 months) were analysed using an autoregressive cross-lagged model.

Results

Hedonic hunger scores decreased from 2.71 (s.d. = .91) at baseline to 2.41 (s.d. = .88) at 3 months (p < .001, CI .22 to .38), remained reduced to 24 months, and were not affected by intervention arm at any time point (p’s>.05). Baseline hedonic hunger scores predicted 3-month scores (B = .76, SE = .03, p < .001, CI .71 to .82), 3-month scores predicted 12-month scores (B = .76, SE = .03, p < .001 CI .72 to .80), and 12-month scores predicted 24-month scores (B = .72, SE = .03, p < .001, CI .64 to .77). Higher hedonic hunger at 3 months predicted higher BMI at 12 months (B = .04, SE = .02, p = .03, CI .01 to .07) but not at 24 months (p>.05). BMI at 12 months was lower in WW52 30.87kg/m², s.d. = 5.02) than WW12 (32.12 kg/m², s.d. = 5.58, p = .02, CI .16 to 2.34) and BI (32.74 kg/m², s.d. = 4.15, p = .01, CI .30 to 3.45). BMI was not affected by intervention at any other time point (p’s>.05).

Conclusion

Hedonic hunger reduced during weight management irrespective of intervention. Early reductions in hedonic hunger appear to be associated with lower BMI in the medium-term. Identifying ways to reduce hedonic hunger during weight loss could aid weight management for some people.

Positive maternal attitudes to following healthy infant feeding guidelines attenuate the associations between infant appetitive traits and both infant milk intake and weight

Appetitive traits influence food intake and weight gain throughout the life-course. Here, we investigated whether maternal attitudes to following healthy infant feeding guidelines could modify this association. Baseline data from 544 mother-infant formula-feeding dyads recruited to the Baby Milk Trial were included in this observational, cross-sectional analysis. Infant appetitive traits (food responsiveness and satiety responsiveness), maternal attitudes to following healthy infant feeding guidelines (self-efficacy, outcome-expectancy, intentions) and infant milk intakes were reported by mothers through questionnaires. Infant weight was measured using standard procedures. Associations between the maternal attitudes score or infant appetitive traits with infant milk intake and infant weight were evaluated in linear regression models adjusted for infant sex and age. To identify effect modification, the interaction term between the maternal attitudes score and infant appetitive trait was added to the model. Infants' mean age and weight were 2.3 months (SD = 0.9) and 5.5 kg (SD = 0.9), respectively. The mean daily infant milk intake reported by mothers was 895 ml/day (SD = 215). Higher maternal attitudes score was associated with lower infant milk intake (Beta = -68.4 ml/day/unit (95% CI: 96.6, -40.2)) and infant weight (Beta = -0.13 SD/unit (-0.25, -0.02)). The maternal attitudes score showed interactions with infant food responsiveness on infant milk intake (p = 0.049), and with infant satiety responsiveness on infant weight (p = 0.01). In both cases, a higher maternal attitudes score attenuated the associations between infant appetitive traits and those outcomes. This analysis provides evidence that positive maternal attitudes to following healthy infant feeding guidelines attenuate the effects of infant appetitive traits on infant milk intake and body weight.

Mechanisms of Action in a Behavioral Weight-Management Program: Latent Growth Curve Analysis

Background

A greater understanding of the mechanisms of action of weight-management interventions is needed to inform the design of effective interventions.

Purpose

To investigate whether dietary restraint, habit strength, or diet self-regulation mediated the impact of a behavioral weight-management intervention on weight loss and weight loss maintenance.

Methods

Latent growth curve analysis (LGCA) was conducted on trial data in which adults (N = 1,267) with a body mass index (BMI) ≥28 kg/m² were randomized to either a brief intervention (booklet on losing weight), a 12 week weight-management program or the same program for 52 weeks. LGCA estimated the trajectory of the variables over four time points (baseline and 3, 12 and 24 months) to assess whether potential mechanisms of action mediated the impact of the weight-management program on BMI.

Results

Participants randomized to the 12 and 52 week programs had a significantly greater decrease in BMI than the brief intervention. This direct effect became nonsignificant when dietary restraint, habit strength, and autonomous diet self-regulation were controlled for. The total indirect effect was significant for both the 12 (estimate = −1.33, standard error [SE] = 0.41, p = .001) and 52 week (estimate = −2.13, SE = 0.52, p < .001) program. Only the individual indirect effect for dietary restraint was significant for the 12 week intervention, whereas all three indirect effects were significant for the 52 week intervention.

Conclusions

Behavior change techniques that target dietary restraint, habit strength, and autonomous diet self-regulation should be considered when designing weight loss and weight loss maintenance interventions. Longer interventions may need to target both deliberative and automatic control processes to support successful weight management.

The impact of adult behavioural weight management interventions on mental health: A systematic review and meta-analysis

There is good evidence that behavioural weight management interventions improve physical health; however, the impact on mental health remains unclear. We evaluated the impact of behavioural weight management interventions on mental health-related outcomes in adults with overweight or obesity at intervention-end and 12 months from baseline. Eligible studies were randomized controlled trials (RCTs) or cluster RCTs of adult behavioural weight loss interventions reporting affect, anxiety, binge eating, body image, depression, emotional eating, quality of life, self-esteem and stress. We searched seven databases from inception to 7 May 2019 and included 43 articles reporting 42 RCTs. Eighteen studies were deemed to be at high risk of bias. We conducted random-effects meta-analyses, stratified analyses and meta-regression using Stata. Interventions generated greater improvements than comparators for depression, mental health-related quality of life and self-efficacy at intervention-end and 12 months from baseline. There was no difference between groups for anxiety, overall quality of life, self-esteem or stress at intervention-end. There was insufficient evidence to assess the impact on anxiety, binge eating, body image, emotional eating, affect, life satisfaction, self-esteem or stress at intervention-end and/or 12 months from baseline. Although evidence suggests that interventions benefit some aspects of mental health, high-quality, transparently reported RCTs measuring a range of mental health outcomes over longer durations are required to strengthen the evidence base.

Inequalities in the uptake of, adherence to and effectiveness of behavioural weight management interventions: systematic review protocol

INTRODUCTION

It has been suggested that interventions focusing on individual behaviour change, such as behavioural weight management interventions, may exacerbate health inequalities. These intervention-generated inequalities may occur at different stages, including intervention uptake, adherence and effectiveness. We will synthesise evidence on how different measures of inequality moderate the uptake, adherence and effectiveness of behavioural weight management interventions in adults.

METHODS AND ANALYSIS

We will update a previous systematic literature review from the United States Preventive Services Taskforce to identify trials of behavioural weight management interventions in adults aged 18 years and over that were, or could feasibly be, conducted in or recruited from primary care. Medline, Cochrane database (CENTRAL) and PsycINFO will be searched. Only randomised controlled trials (RCTs) and cluster-RCTs will be included. Two investigators will independently screen articles for eligibility and conduct risk of bias assessment. We will curate publication families for eligible trials. The PROGRESS-Plus acronym (place of residence, race/ethnicity, occupation, gender, religion, education, socioeconomic status, social capital, plus other discriminating factors) will be used to consider a comprehensive range of health inequalities. Data on trial uptake, intervention adherence, weight change and PROGRESS-Plus-related data will be extracted. Data will be synthesised narratively. We will present a Harvest plot for each PROGRESS-Plus criterion and whether each trial found a negative, positive or no health inequality gradient. We will also identify potential sources of unpublished original research data on these factors which can be synthesised through a future individual participant data meta-analysis.

ETHICS AND DISSEMINATION

Ethical approval is not required as no primary data are being collected. The completed systematic review will be disseminated in a peer-reviewed journal, at conferences, and contribute to the lead author's PhD thesis. Authors of trials included in the completed systematic review may be invited to collaborate on a future individual participant data meta-analysis.

PROSPERO REGISTRATION NUMBER

CRD42020173242.

The effect of referral to an open-group behavioural weight-management programme on the relative risk of normoglycaemia, non-diabetic hyperglycaemia and type 2 diabetes: Secondary analysis of the WRAP trial

AIM

To examine the impact of open-group behavioural weight-management programmes on the risk of diabetes among those with a body mass index (BMI) of ≥28 kg/m² and those with non-diabetic hyperglycaemia (NDH).

METHODS

This was a secondary analysis of data from the WRAP trial, in which participants (N = 1267; aged ≥18 years, BMI ≥ 28 kg/m² ) were randomized to brief intervention (BI; self-help booklet), a weight-management programme (WW; formerly Weight Watchers) for 12 weeks, or WW for 52 weeks. We used multinomial logistic regression to examine the effect of intervention group on the risk of hyperglycaemia and diabetes at 12 months in all participants with glycaemic status at both time points (N = 480; 38%) and those with NDH at baseline (N = 387; 31%). We used mixed effects models and linear fixed effects models to examine the effect of intervention group on body weight and HbA1c at 12 months in people with NDH.

RESULTS

There was a 61% relative reduction in the risk of NDH at the 12-month follow-up (12 weeks vs. BI: relative risk ratio [RRR] = 0.39 [95% CI 0.18, 0.87], P = .021; 52 weeks vs. BI: RRR = 0.38 [95% CI 0.17, 0.86], P = .020). For intervention effects on the risk of diabetes, confidence intervals were wide and overlapped 1 [12 weeks vs. BI: RRR = 0.49 [95% CI 0.12, 1.96], P = .312; 52 weeks vs. BI: RRR = 0.40 [95% CI 0.10, 1.63], P = .199). Participants with hyperglycaemia at baseline in the weight-management programme were more probable to have normoglycaemia at the 12-month follow-up [12-week programme vs. BI: RRR = 3.57 [95% CI 1.24, 10.29], P = .019; 52-week programme vs. BI: RRR = 4.14 [95% CI 1.42, 12.12], P = .009).

CONCLUSIONS

Open-group behavioural weight-management programmes can help to prevent the development of NDH in people with overweight and obesity and to normalize glycaemia in people with NDH.

Cognitive and behavioural strategies employed to overcome "lapses" and prevent "relapse" among weight-loss maintainers and regainers: A qualitative study

While many behavioural weight management programmes are effective in the short-term, post-programme weight regain is common. Overcoming "lapses" and preventing "relapse" has been highlighted as important in weight-loss maintenance, but little is known on how this is achieved. This study aimed to compare the cognitive and behavioural strategies employed to overcome "lapses" and prevent "relapse" by people who had regained weight or maintained weight-loss after participating in a weight management programme. By investigating differences between groups, we intended to identify strategies associated with better weight-loss maintenance. Semi-structured interviews were conducted with 26 participants (58% female) recruited from the 5-year follow-up of the Weight Loss Referrals for Adults in Primary Care (WRAP) trial (evaluation of a commercial weight-loss programme). Participants who had lost ≥5% baseline weight during the active intervention were purposively sampled according to 5-year weight trajectories (n = 16 'Regainers', n = 10 'Maintainers'). Interviews were audio-recorded, transcribed verbatim, and analysed thematically. Key differences in strategies were that Maintainers continued to pay attention to their dietary intake, anticipated and planned for potential lapses in high-risk situations, and managed impulses using distraction techniques. Regainers did not report making plans, used relaxed dietary monitoring, found distraction techniques to be ineffective and appeared to have difficulty navigating food within interpersonal relationships. This study is one of the longest qualitative follow-ups of a weight loss trial to date, offering unique insights into long-term maintenance. Future programmes should emphasize strategies focusing on self-monitoring, planning and managing interpersonal relationships to help participants successfully maintain weight-loss in the longer-term.

Greater Attendance at a Community Weight Loss Programme over the First 12 Weeks Predicts Weight Loss at 2 Years

BACKGROUND

There is considerable heterogeneity in long-term weight loss among people referred to obesity treatment programmes. It is unclear whether attendance at face-to-face sessions in the early weeks of the programme is an independent predictor of long-term success.

OBJECTIVE

To investigate whether frequency of attendance at a community weight loss programme over the first 12 weeks is associated with long-term weight change.

METHODS

Participants were randomised to receive brief support only (control, n = 211), or a weight loss programme for 12 weeks (n = 530) or 52 weeks (n = 528). This study included participants with data on session attendance over the first 12 weeks (n = 889) compared to the control group. The association between attendance (continuously) and weight loss was explored using a linear model. A multi-level mixed-effects linear model was used to investigate whether attendance (categorised as 0, 1, 2-5, 6-9, and 10-12 sessions) was associated with weight loss at 3, 12, and 24 months compared to the control.

RESULTS

For every session attended in the first 12 weeks, the average weight loss was -0.259 kg/session at 24 months (p = 0.005). Analysis by attendance group found only those attending 10-12 sessions had significantly greater weight loss (-7.5 kg [95% CI -8.1 to -6.9] at 12 months; -4.7 kg [95% CI -5.3 to -4.1] at 24 months) compared to the control group (-3.4 [95% CI -4.5 to -2.4] at 12 months, -2.5 [95% CI -3.5 to -1.5] at 24 months). Early attendance was higher for people ≥70 years, but there was no evidence of a difference by gender, ethnicity, education, or income.

CONCLUSIONS

Greater attendance at a community weight loss programme in the first 12 weeks is associated with enhanced weight loss up to 24 months. Regular attendance at a programme could be used as a criterion for continued provision of weight loss services to maximise the cost-effectiveness of interventions.

Third-wave cognitive behaviour therapies for weight management: A systematic review and network meta-analysis

This systematic review and network meta-analysis synthesized evidence on the effects of third-wave cognitive behaviour therapies (3wCBT) on body weight, and psychological and physical health outcomes in adults with overweight or obesity. Studies that included a 3wCBT for the purposes of weight management and measured weight or body mass index (BMI) pre-intervention and ≥ 3 months post-baseline were identified through database searches (MEDLINE, CINAHL, Embase, Cochrane database [CENTRAL], PsycINFO, AMED, ASSIA, and Web of Science). Thirty-seven studies were eligible; 21 were randomized controlled trials (RCT) and included in the network meta-analyses. Risk of bias was assessed using RoB2, and evidence quality was assessed using GRADE. Random-effects pairwise meta-analysis found moderate- to high-quality evidence suggesting that 3wCBT had greater weight loss than standard behavioural treatment (SBT) at post-intervention (standardized mean difference [SMD]: -0.09, 95% confidence interval [CI]: -0.22, 0.04; N = 19; I2 = 32%), 12 months (SMD: -0.17, 95% CI: -0.36, 0.02; N = 5; I2 = 33%), and 24 months (SMD: -0.21, 95% CI: -0.42, 0.00; N = 2; I2 = 0%). Network meta-analysis compared the relative effectiveness of different types of 3wCBT that were not tested in head-to-head trials up to 18 months. Acceptance and commitment therapy (ACT)-based interventions had the most consistent evidence of effectiveness. Only ACT had RCT evidence of effectiveness beyond 18 months. Meta-regression did not identify any specific intervention characteristics (dose, duration, delivery) that were associated with greater weight loss. Evidence supports the use of 3wCBT for weight management, specifically ACT. Larger trials with long-term follow-up are needed to identify who these interventions work for, their most effective components, and the most cost-effective method of delivery.

Clinical and cost-effectiveness of a diabetes education and behavioural weight management programme versus a diabetes education programme in adults with a recent diagnosis of type 2 diabetes: study protocol for the Glucose Lowering through Weight management (GLoW) randomised controlled trial

INTRODUCTION

People with type 2 diabetes (T2D) can improve glycaemic control or even achieve remission through weight loss and reduce their use of medication and risk of cardiovascular disease. The Glucose Lowering through Weight management (GLoW) trial will evaluate whether a tailored diabetes education and behavioural weight management programme (DEW) is more effective and cost-effective than a diabetes education (DE) programme in helping people with overweight or obesity and a recent diagnosis of T2D to lower their blood glucose, lose weight and improve other markers of cardiovascular risk.

METHODS AND ANALYSIS

This study is a pragmatic, randomised, single-blind, parallel group, two-arm, superiority trial. We will recruit 576 adults with body mass index>25 kg/m² and diagnosis of T2D in the past 3 years and randomise them to a tailored DEW or a DE programme. Participants will attend measurement appointments at a local general practitioner practice or research centre at baseline, 6 and 12 months. The primary outcome is 12-month change in glycated haemoglobin. The effect of the intervention on the primary outcome will be estimated and tested using a linear regression model (analysis of covariance) including randomisation group and adjusted for baseline value of the outcome and the randomisation stratifiers. Participants will be included in the group to which they were randomised, under the intention-to-treat principle. Secondary outcomes include 6-month and 12-month changes in body weight, body fat percentage, systolic and diastolic blood pressure and lipid profile; probability of achieving good glycaemic control; probability of achieving remission from diabetes; probability of losing 5% and 10% body weight and modelled cardiovascular risk (UKPDS). An intention-to-treat within-trial cost-effectiveness analysis will be conducted from NHS and societal perspectives using participant-level data. Qualitative interviews will be conducted with participants to understand why and how the programme achieved its results and how participants manage their weight after the programme ends.

ETHICS AND DISSEMINATION

Ethical approval was received from East of Scotland Research Ethics Service on 15 May 2018 (18/ES/0048). This protocol (V.3) was approved on 19 June 2019. Findings will be published in peer-reviewed scientific journals and communicated to other stakeholders as appropriate.

TRIAL REGISTRATION NUMBER

ISRCTN18399564.

Impact of adult weight management interventions on mental health: a systematic review and meta-analysis protocol

INTRODUCTION

The effects of interventions targeting weight loss on physical health are well described, yet the evidence for mental health is less clear. It is essential to better understand the impact of weight management interventions on mental health to optimise care and minimise risk of harm. We will assess the effect of behavioural weight management interventions on mental health in adults with overweight and obesity.

METHODS AND ANALYSIS

The systematic review will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidance. We will include behavioural weight management interventions with a diet and/or physical activity component focusing on weight loss for adults with a body mass index ≥25 kg/m2. Randomised controlled trials (RCTs) and cluster RCTs will be the only eligible study designs. Outcomes of interest will be related to mental health. The following databases were searched from inception to 07 May 2019: MEDLINE, Embase, Cochrane database (CENTRAL), PsycINFO, ASSIA, AMED and CINAHL. The search strategy was based on four concepts: (1) adults, defined as ≥18 years, with overweight/obesity, defined as BMI ≥25kg/m², (2) weight management interventions, (3) mental health outcomes and (4) study design. The search was restricted to English-language published papers, with no other restrictions applied. Two stage screening for eligibility will be completed by two independent reviewers, with two independent reviewers completing data extraction and risk of bias assessment. Data permitting, a random-effects meta-analysis of outcomes, subgroup analyses and meta-regression will be conducted. If not appropriate, narrative synthesis and 'levels of evidence' assessment will be completed.

ETHICS AND DISSEMINATION

Ethical approval is not required as primary data will not be collected. The completed systematic review will be disseminated in a peer-reviewed journal, at conferences and contribute towards the lead author's PhD thesis.

PROSPERO REGISTRATION NUMBER

CRD42019131659.

Changes in behaviors after diagnosis of type 2 diabetes and 10-year incidence of cardiovascular disease and mortality

Background

Large changes in health behaviors achieved through intensive lifestyle intervention programs improve cardiovascular disease (CVD) risk factors among adults with type 2 diabetes. However, such interventions are not widely available, and there is limited evidence as to whether changes in behaviors affect risk of CVD events.

Methods

Among 852 adults with screen-detected type 2 diabetes in the ADDITION-Cambridge study, we assessed changes in diet, physical activity, and alcohol use in the year following diabetes diagnosis. Participants were recruited from 49 general practices in Eastern England from 2002 to 2006, and were followed through 2014 for incidence of CVD events (n = 116) and all-cause mortality (n = 127). We used Cox proportional hazards regression to estimate hazard ratios (HR) for the associations of changes in behaviors with CVD and all-cause mortality. We estimated associations with CVD risk factors using linear regression. We considered changes in individual behaviors and overall number of healthy changes. Models adjusted for demographic factors, bodyweight, smoking, baseline value of the health behavior, and cardio-protective medication use.

Results

Decreasing alcohol intake by ≥ 2 units/week was associated with lower hazard of CVD vs maintenance [HR: 0.56, 95% CI 0.36, 0.87]. Decreasing daily calorie intake by ≥ 300 kcal was associated with lower hazard of all-cause mortality vs maintenance [HR: 0.56, 95% CI 0.34, 0.92]. Achieving ≥ 2 healthy behavior changes was associated with lower hazard of CVD vs no healthy changes [HR: 0.39, 95% CI 0.18, 0.82].

Conclusions

In the year following diabetes diagnosis, small reductions in alcohol use were associated with lower hazard of CVD and small reductions in calorie intake were associated with lower hazard of all-cause mortality in a population-based sample. Where insufficient resources exist for specialist-led interventions, achievement of moderate behavior change targets is possible outside of treatment programs and may reduce long-term risk of CVD complications.

Trial registration This trial is registered as ISRCTN86769081. Retrospectively registered 15 December 2006

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0902-5) contains supplementary material, which is available to authorized users.

Moderate weight change following diabetes diagnosis and 10 year incidence of cardiovascular disease and mortality

AIMS/HYPOTHESIS

Adults with type 2 diabetes are at high risk of developing cardiovascular disease (CVD). Evidence of the impact of weight loss on incidence of CVD events among adults with diabetes is sparse and conflicting. We assessed weight change in the year following diabetes diagnosis and estimated associations with 10 year incidence of CVD events and all-cause mortality.

METHODS

In a cohort analysis among 725 adults with screen-detected diabetes enrolled in the Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen-Detected Diabetes in Primary Care (ADDITION)-Cambridge trial, we estimated HRs for weight change in the year following diabetes diagnosis and 10 year incidence of CVD (n = 99) and all-cause mortality (n = 95) using Cox proportional hazards regression. We used linear regression to estimate associations between weight loss and CVD risk factors. Models were adjusted for age, sex, baseline BMI, smoking, occupational socioeconomic status, cardio-protective medication use and treatment group.

RESULTS

Loss of ≥5% body weight in the year following diabetes diagnosis was associated with improvements in HbA_1c and blood lipids and a lower hazard of CVD at 10 years compared with maintaining weight (HR 0.52 [95% CI 0.32, 0.86]). The associations between weight gain vs weight maintenance and CVD (HR 0.41 [95% CI 0.15, 1.11]) and mortality (HR 1.63 [95% CI 0.83, 3.19]) were less clear.

CONCLUSIONS/INTERPRETATION

Among adults with screen-detected diabetes, loss of ≥5% body weight during the year after diagnosis was associated with a lower hazard of CVD events compared with maintaining weight. These results support the hypothesis that moderate weight loss may yield substantial long-term CVD reduction, and may be an achievable target outside of specialist-led behavioural treatment programmes.

Third-wave cognitive behaviour therapies for weight management: systematic review and network meta-analysis protocol

INTRODUCTION

Behavioural and cognitive behavioural programmes are commonly used to assist with weight management, but there is considerable scope to improve their effectiveness, particularly in the longer term. Third-wave cognitive behaviour therapies (CBTs) have this potential and are increasingly used. This systematic review will assess the effect of third-wave CBTs for weight management on weight, psychological and physical health outcomes in adults with overweight or obesity.

METHODS AND ANALYSIS

The systematic review will be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidance. We will include studies of any third-wave CBTs focusing on weight loss or weight maintenance for adults with a body mass index (BMI) ≥25kg/m2. Eligible study designs will be randomised control trials, non-randomised trials, prospective cohort and case series. Outcomes of interest will be body weight/BMI, psychological and physical health, and adherence. We will search the following databases from inception to 16 January 2018: MEDLINE, CINAHL, Embase, Cochrane database (CENTRAL), PsycINFO, AMED, ASSIA and Web of Science. The search strategy will be based on the concepts: (1) third-wave CBTs and (2) overweight, obesity or weight management. No restrictions will be applied. We will search reference lists of relevant reviews and included articles. Two independent reviewers will screen articles for eligibility using a two-stage process. Two independent reviewers will extract data, assess risk of bias using Risk of Bias 2.0, Risk of Bias in Non-randomised studies of Interventions or Risk of Bias in Non-randomised Studies of Exposures checklist and assess quality using the Grading of Recommendations Assessment, Development and Evaluation tool. A random-effects network meta-analysis of outcomes, and sub-group analyses and meta-regression will be conducted, where data permit. If not appropriate, a narrative synthesis will be undertaken.

ETHICS AND DISSEMINATION

Ethical approval is not required as no primary data will be collected. The completed systematic review will be disseminated in a peer-reviewed journal, presented at conferences and used to inform the development of a weight management programme.

PROSPERO REGISTRATION NUMBER

CRD42018088255.

Greater improvements in diet quality among overweight participants following a group-based commercial weight loss programme than those receiving support to lose weight in primary care

BACKGROUND

Relatively little is known about dietary changes and their relationships with weight change during behavioural weight loss interventions. In a secondary analysis of data from a multicentre RCT, we investigated whether greater improvements in diet would be achieved by overweight adults following a 12 month group-based commercial weight loss programme (CP) than those receiving standard care (SC) in primary practice, and if these dietary changes were associated with greater weight loss.

METHODS

Adults with a BMI 27-35 kg/m2 and >1 risk factor for obesity-related disorders were recruited in study centres in Australia and the UK during 2007-2008. Dietary intake and body weight were measured at baseline, 6 and 12 months. Linear mixed effects models compared mean changes in dietary macronutrient intake, fibre density and energy density over time between groups, and their relationships with weight loss.

RESULTS

The CP group demonstrated greater mean weight loss than the SC group at 6 months (3.3 kg, 95% CI: 2.2, 4.4) and 12 months (3.3 kg, 95% CI: 2.1, 4.5). Diet quality improved in both intervention groups at 6 and 12 months. However, the CP group (n = 228) achieved significantly greater mean reductions in energy intake (mean difference; 95% CI: - 503 kJ/d; - 913, - 93), dietary energy density (- 0.48 MJ/g; - 0.81, - 0.16), total fat (- 6.9 g/d; - 11.9, - 1.8), saturated fat (- 3.3 g/d; - 5.4, - 1.1), and significantly greater mean increases in fibre density (0.30 g/MJ; 0.15, 0.44) at 6 months than the SC group (n = 239). Similar differences persisted at 12 months and the CP group showed greater mean increases in protein density (0.65 g/MJ). In both groups, weight loss was associated with increased fibre density (0.68 kg per g/MJ, 95% CI: 0.08, 1.27) and protein density (0.26 kg per g/MJ, 95% CI: 0.10, 0.41).

CONCLUSIONS

Following a group-based commercial program led to greater improvements in diet quality than standard care. Increases in dietary protein and fibre density were independently associated with weight loss in both behavioural weight loss interventions. Greater increases in protein and fibre density in the commercial program likely contributed to their greater weight loss.

TRIAL REGISTRATION

ISRCTN: ISRCTN85485463 Registered 03/08/2007 Retrospectively Registered.

Extended and standard duration weight-loss programme referrals for adults in primary care (WRAP): a randomised controlled trial

BACKGROUND

Evidence exist that primary care referral to an open-group behavioural programme is an effective strategy for management of obesity, but little evidence on optimal intervention duration is available. We aimed to establish whether 52-week referral to an open-group weight-management programme would achieve greater weight loss and improvements in a range of health outcomes and be more cost-effective than the current practice of 12-week referrals.

METHODS

In this non-blinded, parallel-group, randomised controlled trial, we recruited participants who were aged 18 years or older and had body-mass index (BMI) of 28 kg/m2 or higher from 23 primary care practices in England. Participants were randomly assigned (2:5:5) to brief advice and self-help materials, a weight-management programme (Weight Watchers) for 12 weeks, or the same weight-management programme for 52 weeks. We followed-up participants over 2 years. The primary outcome was weight at 1 year of follow-up, analysed with mixed-effects models according to intention-to-treat principles and adjusted for centre and baseline weight. In a hierarchical closed-testing procedure, we compared combined behavioural programme arms with brief intervention, then compared the 12-week programme and 52-week programme. We did a within-trial cost-effectiveness analysis using person-level data and modelled outcomes over a 25-year time horizon using microsimulation. This study is registered with Current Controlled Trials, number ISRCTN82857232.

FINDINGS

Between Oct 18, 2012, and Feb 10, 2014, we enrolled 1269 participants. 1267 eligible participants were randomly assigned to the brief intervention (n=211), the 12-week programme (n=528), and the 52-week programme (n=528). Two participants in the 12-week programme had been found to be ineligible shortly after randomisation and were excluded from the analysis. 823 (65%) of 1267 participants completed an assessment at 1 year and 856 (68%) participants at 2 years. All eligible participants were included in the analyses. At 1 year, mean weight changes in the groups were -3·26 kg (brief intervention), -4·75 kg (12-week programme), and -6·76 kg (52-week programme). Participants in the behavioural programme lost more weight than those in the brief intervention (adjusted difference -2·71 kg, 95% CI -3·86 to -1·55; p<0·0001). The 52-week programme was more effective than the 12-week programme (-2·14 kg, -3·05 to -1·22; p<0·0001). Differences between groups were still significant at 2 years. No adverse events related to the intervention were reported. Over 2 years, the incremental cost-effectiveness ratio (ICER; compared with brief intervention) was £159 per kg lost for the 52-week programme and £91 per kg for the 12-week programme. Modelled over 25 years after baseline, the ICER for the 12-week programme was dominant compared with the brief intervention. The ICER for the 52-week programme was cost-effective compared with the brief intervention (£2394 per quality-adjusted life-year [QALY]) and the 12-week programme (£3804 per QALY).

INTERPRETATION

For adults with overweight or obesity, referral to this open-group behavioural weight-loss programme for at least 12 weeks is more effective than brief advice and self-help materials. A 52-week programme produces greater weight loss and other clinical benefits than a 12-week programme and, although it costs more, modelling suggests that the 52-week programme is cost-effective in the longer term.

FUNDING

National Prevention Research Initiative, Weight Watchers International (as part of an UK Medical Research Council Industrial Collaboration Award).

Impact of weight maintenance and loss on diabetes risk and burden: a population-based study in 33,184 participants

BACKGROUND

Weight loss in individuals at high risk of diabetes is an effective prevention method and a major component of the currently prevailing diabetes prevention strategies. The aim of the present study was to investigate the public health potential for diabetes prevention of weight maintenance or moderate weight loss on a population level in an observational cohort with repeated measurements of weight and diabetes status.

METHODS

Height, weight and diabetes status were objectively measured at baseline and 10 year follow-up in a population-based cohort of 33,184 participants aged 30-60 years between 1990 and 2013 in Västerbotten County, Sweden. The association between risk of incident diabetes and change in BMI or relative weight was modelled using multivariate logistic regression. Population attributable fractions (PAF) were used to assess population impact of shift in weight.

RESULTS

Mean (SD) BMI at baseline was 25.0 (3.6) kg/m². Increase in relative weight between baseline and follow-up was linearly associated with incident diabetes risk, odds ratio (OR) 1.05 (95% confidence interval (CI) 1.04-1.06) per 1% change in weight. Compared to weight maintenance (±1.0 kg/m²), weight gain of > +1.0 kg/m² was associated with an increased risk of incident diabetes, OR 1.52 (95% CI 1.32, 1.74), representing a PAF of 21.9% (95% CI 15.8, 27.6%). For moderate weight loss (-1.0 to -2.0 kg/m²) the OR was 0.72 (95% CI 0.52, 0.99).

CONCLUSIONS

Weight maintenance in adulthood is strongly associated with reduced incident diabetes risk and there is considerable potential for diabetes prevention in promoting this as a whole population strategy.

The Presence of Real Food Usurps Hypothetical Health Value Judgment in Overweight People

To develop more ecologically valid models of the neurobiology of obesity, it is critical to determine how the neural processes involved in food-related decision-making translate into real-world eating behaviors. We examined the relationship between goal-directed valuations of food images in the MRI scanner and food consumption at a subsequent ad libitum buffet meal. We observed that 23 lean and 40 overweight human participants showed similar patterns of value-based neural responses to health and taste attributes of foods. In both groups, these value-based responses in the ventromedial PFC were predictive of subsequent consumption at the buffet. However, overweight participants consumed a greater proportion of unhealthy foods. This was not predicted by in-scanner choices or neural response. Moreover, in overweight participants alone, impulsivity scores predicted greater consumption of unhealthy foods. Overall, our findings suggest that, while the hypothetical valuation of the health of foods is predictive of eating behavior in both lean and overweight people, it is only the real-world food choices that clearly distinguish them.

Effect of reducing portion size at a compulsory meal on later energy intake, gut hormones, and appetite in overweight adults

OBJECTIVE

Larger portion sizes (PS) are associated with greater energy intake (EI), but little evidence exists on the appetitive effects of PS reduction. This study investigated the impact of reducing breakfast PS on subsequent EI, postprandial gastrointestinal hormone responses, and appetite ratings.

METHODS

In a randomized crossover design (n = 33 adults; mean BMI 29 kg/m(2) ), a compulsory breakfast was based on 25% of gender-specific estimated daily energy requirements; PS was reduced by 20% and 40%. EI was measured at an ad libitum lunch (240 min) and snack (360 min) and by weighed diet diaries until bed. Blood was sampled until lunch in 20 participants. Appetite ratings were measured using visual analogue scales.

RESULTS

EI at lunch (control: 2,930 ± 203; 20% reduction: 2,853 ± 198; 40% reduction: 2,911 ± 179 kJ) and over the whole day except breakfast (control: 7,374 ± 361; 20% reduction: 7,566 ± 468; 40% reduction: 7,413 ± 417 kJ) did not differ. Postprandial PYY, GLP-1, GIP, insulin, and fullness profiles were lower and hunger, desire to eat, and prospective consumption higher following 40% reduction compared to control. Appetite ratings profiles, but not hormone concentrations, were associated with subsequent EI.

CONCLUSIONS

Smaller portions at breakfast led to reductions in gastrointestinal hormone secretion but did not affect subsequent energy intake, suggesting small reductions in portion size may be a useful strategy to constrain EI.

Offering within-category food swaps to reduce energy density of food purchases: a study using an experimental online supermarket

Background

Swaps are often used to encourage healthier food choices, but there is little evidence of their effectiveness. The current study assessed the impact of offering swaps on groceries purchased within a bespoke online supermarket; specifically the objective was to measure the impact on energy density (ED) of food purchases following the offer of lower ED alternatives (a) at point of selection or at checkout, and (b) with or without explicit consent to receive swap prompts.

Method

Participants were asked to complete a 12-item shopping task within an online shopping platform, developed for studying food purchasing. 1610 adults were randomly assigned to a no swap control condition or to one of four interventions: consented swaps at selection; consented swaps at checkout; imposed swaps at selection; or imposed swaps at checkout. Each swap presented two lower ED options from the same category as the participant’s chosen food. Swap acceptance rate and purchased food ED were the primary outcomes.

Results

Of the mean 12.36 (SD 1.26) foods purchased, intervention participants were offered a mean of 4.1 (SD 1.68) swaps, with the potential to reduce the ED of purchased food (effect (95 % CI): −83 kJ/100 g (−110 – -56), p = <0.0001). A median of one swap (IQR 0 to 2) was accepted, not significantly reducing the purchased food ED (effect (95 % CI): −24 kJ/100 g (4 – -52), p = 0.094). More swaps were accepted when offered at selection than at checkout (OR (95 % CI) = 1.224 (1.11 – 1.35), p < 0.0001), but no differences were seen with consent. Purchased food ED was unaffected by point of swap or consent, but reduced with number of swaps accepted (effect per swap (95 % CI) = −24 kJ/100 g (−35 – -14), p < 0.0001).

Conclusion

Within category swaps did not reduce the ED of food purchases reflecting the observation that the use of swaps within an on-line shopping platform offered small potential gains in ED and a minority was accepted.

Electronic supplementary material

The online version of this article (doi:10.1186/s12966-015-0241-1) contains supplementary material, which is available to authorized users.

Priming healthy eating. You can't prime all the people all of the time

OBJECTIVE

In the context of a food purchasing environment filled with advertising and promotions, and an increased desire from policy makers to guide individuals toward choosing healthier foods, this study tests whether priming methods that use healthy food adverts to increase preference for healthier food generalize to a representative population.

METHODS

In two studies (Study 1 n = 143; Study 2 n = 764), participants were randomly allocated to a prime condition, where they viewed fruit and vegetable advertisements, or a control condition, with no advertisements. A subsequent forced choice task assessed preference between fruits and other sweet snacks. Additional measures included current hunger and thirst, dietary restraint, age, gender, education and self-reported weight and height.

RESULTS

In Study 1, hunger reduced preferences for fruits (OR (95% CI) = 0.38 (0.26-0.56), p <0.0001), an effect countered by the prime (OR (95% CI) = 2.29 (1.33-3.96), p = 0.003). In Study 2, the effect of the prime did not generalize to a representative population. More educated participants, as used in Study 1, chose more fruit when hungry and primed (OR (95% CI) = 1.42 (1.13-1.79), p = 0.003), while less educated participants' fruit choice was unaffected by hunger or the prime.

CONCLUSION

This study provides preliminary evidence that the effects of adverts on healthy eating choices depend on key individual traits (education level) and states (hunger), do not generalize to a broader population and have the potential to increase health inequalities arising from food choice.