Reciprocal effects among changes in weight, body image, and other psychological factors during behavioral obesity treatment: a mediation analysis

Self-regulatory and self-efficacy mechanisms of weight loss in women within a community-based behavioral obesity treatment

Given the traditional methods of treating obesity through education on controlling eating and increasing exercise have largely failed beyond the very short term, a more intensive focus on psychosocial correlates of those weight-loss behaviors has been suggested. Multiple behavioral theories incorporate self-regulation, self-efficacy, and mood; however, their interrelations and effects over both the short and long term within cognitive-behavioral obesity treatments remain unclear. Within a novel community-based program with women with obesity who had either low (n = 29) or high (n = 71) mood disturbance scores, there were significant improvements in exercise- and eating-related self-regulation and eating-related self-efficacy-primary targets of that intervention-with no significant difference in those changes by mood disturbance grouping. Changes in the summed exercise- and eating-related self-regulation scores significantly mediated relationships between changes in eating-related self-efficacy and weight (over both 6 and 12 months). There were similar results with mediation assessed via the extent exercise-related self-regulation carried over to eating-related self-regulation. In both of those models a reciprocal relationship between self-regulation and self-efficacy changes was indicated. In serial multiple mediation equations, paths of changes in exercise-related self-regulation → eating-related self-regulation → eating-related self-efficacy → weight were significant. However, paths were not significant when change in self-efficacy was entered as the predictor (initial) variable. Findings suggest viability in first focusing on exercise-related self-regulation, then eating-related self-regulation, in the course of increasing self-efficacy and probabilities for inducing enough sustained weight loss to improve obesity-associated health risks. Benefits of field-based research findings generalizing to weight-management applications were suggested.

Dietary phytochemical index and psychological disorders in a large sample of Iranian adults: a population-based study

BACKGROUND

Intake of plant foods and phytochemicals can decrease the odds of mental health.

AIM

The aim of study is to investigate the association between Dietary Phytochemical Index (DPI) with symptoms of depression, anxiety and stress in a large sample of Iranian adults.

METHODS

In this cross-sectional study, a total of 7385 adults aged 20-50 years old were provided from the recruitment phase of Yazd Health Study, a population-based cohort research on Iranian adults. Food intakes were assessed via a validated and reliable food frequency questionnaire. Symptoms of depression, anxiety and stress were assessed using a validated Depression, Anxiety and Stress Scales questionnaire with 21-items. DPI was calculated by the percent of daily energy intake taken from phytochemical-rich foods.

RESULTS

After adjustment for potential confounders, normal weight subjects in the highest tertile of DPI had lower odds of depression (OR 0.65; 95% CI 0.44-0.97) and anxiety symptoms (OR 0.65; 95% CI 0.45-0.93) compared with those in the lowest tertile. However, the apparent association was not found between depression, anxiety and stress in overweight and obese subjects.

CONCLUSION

We found a significant association between DPI and mental health in normal weight adults. Prospective studies are required to approve these conclusions.

Testing motivational and self-regulatory mechanisms of action on device-measured physical activity in the context of a weight loss maintenance digital intervention: A secondary analysis of the NoHoW trial

BACKGROUND

To date, few digital behavior change interventions for weight loss maintenance focusing on long-term physical activity promotion have used a sound intervention design grounded on a logic model underpinned by behavior change theories. The current study is a secondary analysis of the weight loss maintenance NoHoW trial and investigated putative mediators of device-measured long-term physical activity levels (six to 12 months) in the context of a digital intervention.

METHODS

A subsample of 766 participants (Age = 46.2 ± 11.4 years; 69.1% female; original NoHoW sample: 1627 participants) completed all questionnaires on motivational and self-regulatory variables and had all device-measured physical activity data available for zero, six and 12 months. We examined the direct and indirect effects of Virtual Care Climate on post intervention changes in moderate-to-vigorous physical activity and number of steps (six to 12 months) through changes in the theory-driven motivational and self-regulatory mechanisms of action during the intervention period (zero to six months), as conceptualized in the logic model.

RESULTS

Model 1 tested the mediation processes on Steps and presented a poor fit to the data. Model 2 tested mediation processes on moderate-to-vigorous physical activity and presented poor fit to the data. Simplified models were also tested considering the autonomous motivation and the controlled motivation variables independently. These changes yielded good results and both models presented very good fit to the data for both outcome variables. Percentage of explained variance was negligible for all models. No direct or indirect effects were found from Virtual Care Climate to long term change in outcomes. Indirect effects occurred only between the sequential paths of the theory-driven mediators.

CONCLUSION

This was one of the first attempts to test a serial mediation model considering psychological mechanisms of change and device-measured physical activity in a 12-month longitudinal trial. The model explained a small proportion of variance in post intervention changes in physical activity. We found different pathways of influence on theory-driven motivational and self-regulatory mechanisms but limited evidence that these constructs impacted on actual behavior change. New approaches to test these relationships are needed. Challenges and several alternatives are discussed.

TRIAL REGISTRATION

ISRCTN Registry, ISRCTN88405328. Registered December 16, 2016, https://www.isrctn.com/ISRCTN88405328.

Mediators of weight change in underserved patients with obesity: exploratory analyses from the Promoting Successful Weight Loss in Primary Care in Louisiana (PROPEL) cluster-randomized trial

BACKGROUND

Intensive lifestyle interventions (ILIs) stimulate weight loss in underserved patients with obesity, but the mediators of weight change are unknown.

OBJECTIVES

We aimed to identify the mediators of weight change during an ILI compared with usual care (UC) in underserved patients with obesity.

METHODS

The PROPEL (Promoting Successful Weight Loss in Primary Care in Louisiana) trial randomly assigned 18 clinics (n = 803) to either an ILI or UC for 24 mo. The ILI group received an intensive lifestyle program; the UC group had routine care. Body weight was measured; further, eating behaviors (restraint, disinhibition), dietary intake (percentage fat intake, fruit and vegetable intake), physical activity, and weight- and health-related quality of life constructs were measured through questionnaires. Mediation analyses assessed whether questionnaire variables explained between-group variations in weight change during 2 periods: baseline to month 12 (n = 779) and month 12 to month 24 (n = 767).

RESULTS

The ILI induced greater weight loss at month 12 compared with UC (between-group difference: -7.19 kg; 95% CI: -8.43, -6.07 kg). Improvements in disinhibition (-0.33 kg; 95% CI: -0.55, -0.10 kg), percentage fat intake (-0.25 kg; 95% CI: -0.50, -0.01 kg), physical activity (-0.26 kg; 95% CI: -0.41, -0.09 kg), and subjective fatigue (-0.28 kg; 95% CI: -0.46, -0.10 kg) at month 6 during the ILI partially explained this between-group difference. Greater weight loss occurred in the ILI at month 24, yet the ILI group gained 2.24 kg (95% CI: 1.32, 3.26 kg) compared with UC from month 12 to month 24. Change in fruit and vegetable intake (0.13 kg; 95% CI: 0.05, 0.21 kg) partially explained this response, and no variables attenuated the weight regain of the ILI group.

CONCLUSIONS

In an underserved sample, weight change induced by an ILI compared with UC was mediated by several psychological and behavioral variables. These findings could help refine weight management regimens in underserved patients with obesity.This trial was registered at clinicaltrials.gov as NCT02561221.

Association between weight loss, change in physical activity, and change in quality of life following a corporately sponsored, online weight loss program

Background

The physiological benefits associated with corporately sponsored weight loss programs are increasingly well documented. However, less is known about how these programs affect employees’ quality of life (QoL). The purpose of the present analysis was to examine the association between weight loss, change in physical activity, and change in QoL following a corporately sponsored, online weight loss program.

Methods

We examined the relationship between weight loss, self-reported change in physical activity, and change in several QoL indices in 26,658 participants (79% women) after the initial 10 weeks of the online weight loss program. The trend in changes in each QoL index with increasing weight loss and change in physical activity was examined using logistic regression analysis.

Results

We observed greater improvements in each QoL index with increasing weight loss (p-for-trend, < 0.001) as well as with progressive increases in physical activity (p-for-trend, < 0.001). The combination of increasing weight loss and increases in physical activity were associated with the greatest improvements in each QoL index (additive effect). The percentage of employees reporting improvements in QoL (“improved” or “very much improved”) was 64% for energy, 63% for mood, 33% for sleep, 65% for self-confidence, 68% for indigestion, and 39% for musculoskeletal pain.

Conclusions

Among people, who engage with a commercial weight loss program, greater weight loss during the program was associated with greater improvements in QoL, and increases in physical activity further enhanced the QoL-related benefits.

Gender and Emotional Representation Matter: Own Illness Beliefs and Their Relationship to Obesity

Background

Current treatments of obesity often fail to consider gender and psychological aspects, which are essential for weight loss and weight maintenance. The aim of our study was to analyze subjective illness representations (SIRs) of adults with obesity according to the Common-Sense Self-Regulation Model (CSM) by assessing their associations with weight-related variables and gender.

Methods

Data was collected via online self-assessment between April 2017 and March 2018. SIRs were operationalized by the revised Illness Perception Questionnaire (IPQ-R) and illness outcomes according to the CSM were defined as BMI, eating behaviour, physical wellbeing, bodyweight satisfaction, and shape concerns. The sample consisted of 427 adults (M = 42.2 years, SD = 10.9; 82% female) with obesity (BMI: M = 42.3 kg/m², SD = 9.0). Student's t-tests and multiple hierarchical regression analyses were conducted with the control variables (age and BMI) and subjective illness representations and gender as independent variables.

Results

The explanation of outcome variances was moderate to high (21-43%) except for restraint eating behaviour (10%). Subjective illness representations showed several significant associations with weight-related variables, especially timeline and emotional representations. Female gender was significantly associated with more restraint eating behaviour [F_{(1, 400)} = 4.19, p < 0.001] and females had unfavourable values of the weight-related variables as well as a more cyclic [t₍₄₂₅₎ = 3.68, p < 0.001], and more emotional representation [t₍₁₀₀₎ = 5.17, p < 0.001] of their obesity.

Conclusion

The results of this study indicate that gender and subjective illness representations, especially the emotional representation, play an important role for weight-related variables. Therefore, the assessment of SIRs may constitute an economic tool to identify specific individual deficits of self-regulation.

Factors associated with the improvement of body image dissatisfaction of female patients with overweight and obesity during cognitive behavioral therapy

BACKGROUND

Cognitive behavioral therapy (CBT) has become one of the most commonly used psychotherapeutic treatments for obesity. It stems from CBT for bulimia nervosa and binge eating disorder, which focuses on amelioration of the eating behavior and body image dissatisfaction (BID), but usually does not focus on weight loss. In contrast, CBT for obesity focuses on weight loss, as well as eating behavior and BID. It is at present unclear whether the improvement of BID during CBT for obesity is associated with improvement of factors other than weight loss.

OBJECTIVE

The purpose of this study was to determine whether improvement of BID during CBT for obesity was associated with improvement of factors other than weight loss.

METHODS

One hundred and sixty-five women (BMI 31.8 ± 5.2 kg/m², age 49.3 ± 10.5 years) with overweight or obesity completed a 7-month CBT-based weight loss intervention. BID, depression, anxiety, binge eating, and perfectionism were assessed at both baseline and the end of the intervention through the use of psychological questionnaires.

RESULTS

Percent total weight loss, baseline BID, baseline binge eating disorder (BED), change in depression (Δdepression), Δstate anxiety, Δtrait anxiety, Δbinge eating, and Δperfectionism were significantly correlated with ΔBID. Multiple regression analysis showed that baseline BID, baseline BED, percent total weight loss, Δbinge eating, and Δdepression were independently associated with ΔBID.

CONCLUSION

Improvement of binge eating, and improvement of depression, as well as weight loss, were independently associated with amelioration of BID.

CLINICAL TRIAL REGISTRATION

[https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000008052], identifier [UMIN000006803] and [https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R0000 55850], identifier [UMIN000049041].

Body Positivity and Self-Compassion on a Publicly Available Behavior Change Weight Management Program

According to recent research, body positivity and self-compassion are key outcomes that are tied to better psychological and physical health. To date, it is unclear whether body positivity and self-compassion improve, stay constant, or deteriorate over the course of a weight management program, particularly one that addresses the psychological roots of behavior change. Additionally, beyond controlled settings, there are no studies on body positivity and self-compassion in individuals who choose to join a commercial weight management program. Therefore, this single-arm prospective study examined changes in body positivity and self-compassion from baseline to the 16 week milestone of Noom Weight, a commercial behavior change weight management program informed by acceptance and commitment therapy (ACT), dialectical behavior therapy (DBT), and cognitive behavioral therapy (CBT). We also examined how baseline and over-time changes in body positivity and self-compassion predicted engagement in program-measured relevant behaviors (e.g., exercises logged). Participants were a random subset of individuals who had recently self-enrolled in the program (n = 133). Body positivity and self-compassion were measured via survey at baseline and end of the core program (16 weeks). Self-reported weight and program-recorded engagement were extracted from the program database. Compared to baseline, body appreciation, body image flexibility, self-compassion, and body-focused rumination significantly improved at 16 weeks (all ps < 0.007). Participants lost a statistically significant amount of weight (3.9 kg; t(128)) = 10.64, p < 0.001) by 16 weeks, which was 4.4% body weight. Greater engagement, especially messaging a coach, reading articles, and logging meals, was associated with improvements over time in body appreciation (r = 0.17, p = 0.04), body image flexibility (r = −0.23, p = 0.007), and the brooding component of rumination (r = −0.23, p = 0.007). Greater engagement was also associated with baseline total self-compassion (r = 0.19, p = 0.03) and self-judgment (r = 0.24, p = 0.006). The results suggest that individuals experience improvements in body positivity and self-compassion while learning about ACT, DBT, and CBT through curriculum and coaching in this setting. The results also have important clinical implications, such as the possibility that psychologically-oriented (i.e., ACT, DBT, and CBT-based) weight management could be important to improve body positivity or that baseline self-compassion could be used to target individuals at risk for lower engagement. Future work should investigate these possibilities as well as delineate the causal relationships between body positivity, self-compassion, engagement, and weight loss.

How body concerns, body mass, self-rated health and self-esteem are mutually impacted in early adolescence: a longitudinal cohort study

Background

Impaired self-rated health (SRH) and self-esteem (SE) in adolescents are associated with increased body mass index (BMI). These associations are often studied using cross-sectional designs; we performed a longitudinal cohort survey to examine them.

Methods

A longitudinal cohort study of 1225 Norwegian high school students, with SRH, SE and BMI as primary outcomes. We reported the results from temporal causal and residual change analyses separately, with odds ratios (ORs) and standardised regression coefficients (b) and 95% confidence limits.

Results

Body and weight concerns had unfavourable effects on SRH and SE, which both had favourable effects on each other. Increased BMI had unfavourable effects on SRH, but less so on SE. Body and weight concerns impacted SE change only among girls. Paradoxically, the intention of becoming thinner was associated with an increase in BMI, and the intention of becoming fatter predicted a decrease in BMI during the 2 years. SE and SRH were associated with a leaner body after 2 years.

Conclusions

This study confirms that body concerns had unfavourable effects on subjective health, and that positive self-concepts predicted a leaner body. Health promotion strategies built on body acceptance should be increasingly emphasised in clinical and public health practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10553-x.

How are body mass and body attitude impacted by a behaviour change intervention in primary care? A pragmatic randomised controlled trial

Aims:This study evaluated the effect of behaviour change interventions at Norwegian Healthy Life Centres on change in body mass index (BMI) and body attitude, and explored the predictors for change after 6 months. Methods: We randomised 118 participants to either an intervention or a control group. Eligible participants: ⩾18 years and able to take part in group-based interventions. Body attitude, weight, and height were assessed at inclusion and after 6 months. We analysed the data using simple and multiple regression. Results: Eighty-six participants completed 6-month follow-up. The study found no intervention effect on BMI or body attitude across the two groups. However, an interaction effect indicated that the leaner participants in the intervention group reduced their weight significantly (b 0.94, p < 0.001). BMI reduction was predicted by self-efficacy for physical activity and autonomous motivation for change. Weight loss was associated with impaired body attitude, body shape concern, impaired weight-related self-esteem, weight cycling, and controlled motivation for change. Improvement in body attitude was positively impacted by self-rated health, the experience of childhood respect, life satisfaction, and self-efficacy for physical activity. Impaired body attitude was predicted by body shape concern, impaired weight-related self-esteem, and controlled motivation. Conclusions: The interventions did not affect body mass on average, but promoted weight loss among the leaner participants. Because weight reduction was associated body shape concern and impaired body attitude, the study supports the claim that interventions should be weight neutral and aim to improve body image and psychological well-being rather than weight reduction.

Evaluation of Weigh Forward: A group intervention delivered by dietitians and psychologists within a National Health Service specialist weight management service

There is limited evidence of the effectiveness of non-surgical interventions for severe obesity. Our aim was to evaluate a group intervention delivered by a National Health Service (NHS) specialist weight management service to contribute to the evidence base and inform the development of future services. Participants in this prospective cohort study were patients attending NHS Grampian Specialist Weight Management Services. The intervention was an interactive 12-session group programme based on evidence-based psychological model, with combined dietetic and psychological knowledge and support provided. The primary outcome was mean weight change at the end of the intervention and for 12-mo follow-up (including programme completers, baseline observation carried forward [BOCF], last observation carried forward). Secondary outcome measures included mood, anxiety, binge eating and quality of life. A total of 166 patients accepted a place on the group programme, mean body mass index was 48.9 kg/m² . Mean weight loss at 6 mo was 5.6 kg and 35.2% of those who completed the group (n = 88) lost ≥5%. Using BOCF, 18.7% lost ≥5% at 6 mo. Those who remained in the programme maintained their weight loss 12 and 18 mo after the start of the intervention. Significant improvements were also found in psychological variables, including reduced depression, anxiety, binge eating and improved emotion regulation. This real-world evaluation of an NHS intervention for patients with severe obesity suggests that individuals who engage achieve a moderate weight loss, which most maintain a year later, although further research is needed to strengthen this conclusion.

Effects of a Group Protocol on Physical Activity and Associated Changes in Mood and Health Locus of Control in Adults with Parkinson Disease and Reduced Mobility

BACKGROUND

Parkinson disease (PD) is a degenerative nervous disorder that affects motor functioning. Although physical activity is beneficial, it often is reduced, and psychosocial issues persist such as low mood and perceptions of loss of control over health.

OBJECTIVE

To determine the extent to which a community-based physical activity/self-regulatory skills intervention affects overall physical activity and changes in psychosocial factors in adults with PD and in adults with reduced mobility without PD.

METHODS

Existing participants (N = 45, mean age = 71 years) of community-based PD group movement classes, who also participated in an individualized 6-session protocol for exercise support that emphasized self-regulation through barriers, completed validated self-report surveys. Participants' mean length of movement class participation was 11.8 months at the time of survey administration.

RESULTS

Mixed-model repeated-measures analysis of variance indicated significant improvements in physical activity, self-regulation, exercise self-efficacy, negative mood, and task social cohesion but not internal health locus of control. Improvement in social cohesion was significantly greater in the PD group (n = 27) than in the non-PD (n = 18) group. Changes in exercise self-efficacy mediated a significant relationship between changes in self-regulation and physical activity. Changes in social cohesion mediated a significant relationship between changes in physical activity and mood. Changes in mood and social cohesion had a reciprocal, mutually reinforcing relationship. For the PD group, length of program involvement predicted vigor change (r = 0.52, p = 0.006).

CONCLUSION

The intervention demonstrated positive effects on physical activity and psychosocial factors in adults with PD and with reduced mobility. Effects on social cohesion were important. Such programming should be considered as an adjunct to traditional medical treatment.

Effects of Treatment-Associated Increases in Fruit and Vegetable Intake on the Consumption of Other Food Groups and Weight Through Self-Regulatory Processes

CONTEXT

Increased intake of fruits and vegetables (FV) may be useful for weight loss.

OBJECTIVE

This study was designed to evaluate the effects of changes in FV intake on the overall diet and to determine if self-regulation affects the association between changes in FV intake and weight.

METHODS

Women with obesity (N = 74, mean age = 47.7 years) participating in a year-long behavioral weight-loss treatment were assessed regarding changes in consumption of various food groups, physical activity, and eating self-regulation over 6, 12, and 24 months.

RESULTS

FV intake change significantly predicted changes in weight and consumption of dairy and bread products and sweets. The only other notable relationships were among changes in sweets, bread, and dairy consumption over 24 months. Over 6, 12, and 24 months, changes in self-regulation significantly mediated the FV intake-weight change relationship. The overall mediation models were significant (R² values = 0.19, 0.13, and 0.32, respectively). A reciprocal relationship between changes in FV intake and self-regulation also was found. Significant increases in physical activity outputs did not influence weight changes.

CONCLUSION

Findings supported a relationship between FV intake and weight loss occurring through self-regulatory skills. Associations between FV intake and reduced consumption of other food groups provided data useful for improving the architecture of behavioral weight-loss treatments and the foci of medical practitioners' helping methods.

Moderating Effects of Depression, Food Cravings, and Weight-Related Quality-of-Life on Associations of Treatment-Targeted Psychosocial Changes and Physical Activity in Adolescent Candidates for Bariatric Surgery

BACKGROUND

Physical activity is a strong predictor of sustaining weight loss. Yet physical activity has been challenging to maintain. Adolescent bariatric surgery is increasing, and there is typically an initial 6-month period when improving health behaviors such as physical activity are addressed by a clinic-based team. However, there is minimal understanding of how to target psychosocial factors relevant for behavioral changes.

METHODS

A group of 15 adolescent candidates for bariatric surgery (mean age = 15.1 y; mean body mass index = 55.9 kg/m2) were assessed on changes in 3 theory-based predictors of physical activity from baseline-month 3 and baseline-month 6.

RESULTS

Changes in physical activity-related self-regulation and self-efficacy over 3 months significantly predicted change in physical activity over 6 months. Reciprocal relationships were also significant, including the prediction of physical activity change by change in negative mood. The clinical psychology-based factor of weight-related quality-of-life significantly moderated the prediction of self-regulation via physical activity, and degree of depressive symptoms significantly moderated the prediction of changes in physical activity through self-efficacy changes.

CONCLUSIONS

Because improvements in several theory-based psychosocial variables related to physical activity have demonstrated a carry-over to controlling eating, the improved understanding of those variables for treating adolescents with severe obesity was useful.

Relationship of Emotional Eating and Mood Changes Through Self-Regulation Within Three Behavioral Treatments for Obesity

An enhanced understanding of the dynamics of psychosocial change processes within behavioral weight loss treatments is required to improve their generally poor results. Based on social cognitive theory, self-regulation of eating has the possibility of affecting interrelations between psychosocial correlates of inappropriate eating behaviors such as emotional eating and negative mood. Within behavioral interventions, physical activity, treatment foci, and the length of treatment might moderate those relationships. The aim of this research was to contrast intervention effects based on treatment type, and evaluate interrelations of changes in theory-based psychosocial variables. Adult females with obesity (overall Mage = 48.6 years; overall MBMI = 35.3 kg/m2) were block randomized into groups of 28 weeks of phone-supported manual-based education (Group 1, n = 52), 58 weeks of cognitive-behavioral group treatment (Group 2, n = 52), and 99 weeks of cognitive-behavioral group treatment followed by phone-based reviews of intervention materials (Group 3, n = 48). Significant improvements in measures of emotional eating, negative mood, self-regulation for controlling eating, physical activity, and body composition were found in each group over 3, 6, 12, and 24 months, with generally larger effect sizes detected in Groups 2 and 3. Reciprocal, mutually reinforcing, relationships were found between changes in emotional eating and mood, which were significantly mediated by self-regulation changes. Physical activity level significantly moderated mood changes, treatment foci on emotional eating significantly moderated changes in emotional eating, and treatment length significantly moderated long-term changes in emotional eating, but not mood. Findings support a treatment duration of at least one year that emphasizes physical activity and self-regulatory skills usage, and interrelations between changes in emotional eating, self-regulation, mood, and physical activity.

Eating-Related and Psychological Outcomes of Health at Every Size Intervention in Health and Social Services Centers Across the Province of Québec

Purpose:

To report the outcomes of a Health at Every Size (HAES) intervention in a real-world setting.

Design:

Quasi-experimental design evaluating eating behaviors and psychological factors.

Setting:

The HAES intervention is offered in Health and Social Services Centers in Québec (Canada).

Participants:

For this study, 216 women (body mass index [BMI]: 35.76 [6.80] kg/m2) who participated to the HAES intervention were compared to 110 women (BMI: 34.56 [7.30] kg/m2) from a comparison group.

Intervention:

The HAES intervention is composed of 14 weekly meetings provided by health professionals. It focuses on healthy lifestyle, self-acceptance, and intuitive eating.

Measures:

Eating behaviors (ie, flexible restraint, rigid restraint, disinhibition, susceptibility to hunger, intuitive eating, and obsessive-compulsive eating) and psychological correlates (ie, body esteem, self-esteem, and depression) were assessed using validated questionnaires at baseline, postintervention, and 1-year follow-up.

Analysis:

Group, time, and interaction effects analyzed with mixed models.

Results:

Significant group by time interactions were found for flexible restraint ( P = .0400), disinhibition ( P < .0001), susceptibility to hunger ( P < .0001), intuitive eating ( P < .0001), obsessive–compulsive eating ( P < .0001), body-esteem ( P < .0001), depression ( P = .0057), and self-esteem ( P < .0001), where women in the HAES group showed greater improvements than women in the comparison group at short and/or long term.

Conclusion:

The evaluation of this HAES intervention in a real-life context showed its effectiveness in improving eating-, weight-, and psychological-related variables among women struggling with weight and body image.

The Healthy Weights Initiative: results from the first 2,000 participants

BACKGROUND

A free, comprehensive, adult obesity reduction program was initiated in the cities of Moose Jaw and Regina, Saskatchewan, Canada.

OBJECTIVE

This study aimed to determine the short-term and long-term adherence outcomes, identify factors that impact long-term adherence, and measure health outcomes.

METHODS

The Healthy Weights Initiative (HWI) attendance was determined by using an electronic swipe card. An on-site exercise therapist also documented physical activity, duration, and intensity, as well as attendance of dietary and cognitive behavioral therapy education classes. Logistic regression determined which factors were associated with long-term adherence (exercising three times per week at 1 year) and various health outcomes.

RESULTS

In this study, 2,167 participants started and 2,000 completed the 24-week program (92.3%). Upon 24-week completion, the majority of the participants in Moose Jaw (59.0%) and Regina (63.1%) purchased 1-year fitness memberships at the YMCA. At 1 year, 79.8% of the participants were exercising three times a week or more at the Moose Jaw YMCA. Logistic regression revealed that participants who did not exercise three times a week at 1 year at the YMCA were more likely to have a spouse/partner who did not support the program (OR=2.01; 95% CI=1.81-2.22) and more likely to have a medical comorbidity (OR=1.22; 95% CI=1.03-1.49). At 24 weeks, average weight loss was modest (12.7 pounds) and regressed slightly at 1 year (10.4 pounds). However, at 24 weeks, many health gains were statistically significant and were maintained for 1 year. For example, the prevalence of depressed mood reduced from 49.0% at baseline to 13.0% at 24 weeks and increased to 19.0% at 1 year (P=0.000). Conclusion: We found that the availability of a community-based weight management program (Healthy Weights Initiative) demonstrated good adherence, modest weight loss, and positive health outcomes.

The Relationship between Weight Status and Depressive Symptoms in a Population Sample with Obesity: The Mediating Role of Appearance Evaluation

OBJECTIVES

Identifying the underlying pathways between obesity and depression and which individuals with obesity are at risk for developing depressive symptoms is important for improving prevention and treatment efforts. The current study investigated appearance evaluation as a potential mediator of the relationship between obesity and depression.

METHODS

A total of 1,000 participants with a self-reported BMI greater than 30 kg/m2 were interviewed about their experiences with an elevated body weight and completed measures on appearance evaluation and depression.

RESULTS

A negative relationship between satisfaction with appearance and BMI and a negative association between satisfaction with appearance and depression was found in men and women. Men reported less depressive symptoms and higher satisfaction with appearance compared to women. While no mediation effect could be determined in women, satisfaction with appearance mediated the obesity-depression relationship in men.

CONCLUSIONS

Efforts to reduce adverse effects of either obesity or depression need to take the reciprocal relationship between the two conditions into account. The current findings underscore the importance of appearance evaluation for treatment efforts in individuals with obesity. Interventions addressing body image might improve both, psychological distress and weight management efforts in general.

Health-related quality of life in randomized controlled trials of lorcaserin for obesity management: what mediates improvement?

Lorcaserin, plus diet and exercise, has demonstrated significant weight loss and improved cardiometabolic parameters vs. placebo in patients with overweight/obesity in three randomized, placebo-controlled trials. We examined whether lorcaserin is also associated with greater improvements in health-related quality of life (HRQOL) and whether these improvements are wholly attributable to weight loss. Pooled data from Behavioral Modification and Lorcaserin for Overweight and Obesity Management (BLOOM), Behavioral Modification and Lorcaserin Second Study for Obesity Management (BLOSSOM) and BLOOM-Diabetes Mellitus (BLOOM-DM) trials were analysed (n = 5624). HRQOL was assessed at baseline and 52 weeks using the Impact of Weight on Quality of Life-Lite (IWQOL-Lite) questionnaire. Multiple mediation analyses were conducted to evaluate the mechanisms underlying improved HRQOL. Greater HRQOL improvements were observed at 52 weeks in lorcaserin vs. placebo (P < 0.0001). A greater percentage of lorcaserin patients (54.1%) experienced meaningful improvements in IWQOL-Lite total score than placebo patients (48.2%) (P < 0.001). Body mass index (BMI) reduction was the primary driver of improved HRQOL (P < 0.0001), with depressive symptoms and total cholesterol also playing a role (P < 0.05). Improved HRQOL varied by gender, age, race and presence of diabetes and other comorbidities. Lorcaserin treatment significantly improves HRQOL compared with placebo. Although BMI reduction accounts for the majority of these improvements, improvement in depressive symptoms and total cholesterol are contributing factors.

Effects of an after-school care-administered physical activity and nutrition protocol on body mass index, fitness levels, and targeted psychological factors in 5- to 8-year-olds

Over one third of U.S. youth are overweight or obese. Treatments typically have had unreliable effects, inconsistently incorporating behavior-change theory. After-school care might be a viable setting for health behavior-change programs. We evaluated effects of two consecutive 12-week segments of a revised self-efficacy/social cognitive theory-based physical activity and nutrition treatment on fitness levels, body mass index (BMI), and targeted psychosocial factors in after-school care participants, ages 5-8 years. Changes in physiological measures, exercise self-efficacy (ESE), and physical self-concept over 9 months were contrasted in experimental (n = 72) vs. typical-care (n = 42) groups. Mediation of the group-BMI change relationship by the psychosocial factors was also assessed. Improvements in physiological measures and ESE were significantly greater in the experimental group. ESE change completely mediated the association of treatment type with BMI change. The experimental group demonstrated significantly greater improvements in the physiological measures, with its treatment's theoretical basis and application within after-school care supported.

Directionality in the Relationship of Self-regulation, Self-efficacy, and Mood Changes in Facilitating Improved Physical Activity and Nutrition Behaviors: Extending Behavioral Theory to Improve Weight-Loss Treatment Effects

OBJECTIVE

To improve understanding of directionality in the dynamic relationships among psychosocial predictors of behavioral changes associated with weight loss.

METHODS

In women with obesity participating in a new behavioral weight-loss treatment that emphasizes physical activity (n = 53; body mass index = 34.7 ± 3.3 kg/m²), mediation and moderated-mediation models were fit to assess directionality in the self-efficacy-self-regulation change relationship and additional effects of mood change and its basis on fruit/vegetable intake and physical activity behaviors through month 6 and from months 6 to 24.

RESULTS

Self-regulation was a stronger predictor of change in self-efficacy than vice versa. Mood change did not moderate the relationships significantly between changes in self-efficacy and/or self-regulation, and weight loss behavior. Emotional eating significantly changed mediated relationships between changes in mood and fruit/vegetable intake through month 6 (95% confidence interval, -0.05 to 0.00).

CONCLUSIONS AND IMPLICATIONS

Findings clarified relationships of self-efficacy, self-regulation, and mood in the prediction of weight loss behaviors, and informed behavioral treatments for improved outcomes.

Effects of the Youth Fit 4 Life physical activity/nutrition protocol on body mass index, fitness and targeted social cognitive theory variables in 9- to 12-year-olds during after-school care

AIM

Childhood overweight and obesity is unacceptably high in industrialised nations. School-based interventions have largely been atheoretical and ineffective. This study aimed to test a new theory-based protocol for its effects on measures of fitness and body mass index (BMI), and its proposed psychosocial mediators, during elementary after-school (out-of-school hours) care.

METHODS

Nine- to 12-year-old participants of YMCA-based after-school care in the southeastern Unites States were randomised into either the experimental Youth Fit 4 Life (YF4L) treatment group (n = 86) or a typical care group (n = 55) for 45 min/day. YF4L is based on social cognitive theory, emphasising mastery over physical activities and the development of self-management/self-regulatory skills to support healthy behaviours. Physiological and psychosocial variables were assessed over a 9-month elementary school year.

RESULTS

Of the overall sample, 28% were overweight or obese at baseline. YF4L was associated with significantly greater improvements in BMI, and measures of self-regulation, mood, self-efficacy, cardiovascular endurance and strength over both 3 and 9 months. Changes in self-regulation, mood and self-efficacy significantly mediated the treatment type-BMI relationship over both 3 months (R ² = 0.12, P = 0.002) and 9 months (R ² = 0.13, P = 0.001), with change in self-regulation being a significant independent mediator. Changes in BMI and self-regulation reciprocally reinforced one another. Gender was not a significant moderator of those relationships.

CONCLUSIONS

The YF4L treatment mitigated rise in BMI in 9- to 12-year-old enrollees of after-school care. The treatment's basis in social cognitive theory was supported. Because of its positive effects and ability to utilise existing staff, large-scale application is warranted after sufficient replication.

The Impact of Self-Criticism and Self-Reassurance on Weight-Related Affect and Well-Being in Participants of a Commercial Weight Management Programme

OBJECTIVE

Certain psychological and emotional factors can undermine attempts at weight management. Previously we have found that shame and self-criticism were significantly associated with disinhibition and perceived hunger in 2,236 participants of a weight management programme. This effect was fully mediated through weight-related negative affect. The present study examined the impact of self-criticism and self-reassurance on well-being and whether it was mediated by weight-related affect in the same population.

METHODS

Participants completed an online survey of measures of self-criticism and self-reassurance, and negative and positive affect associated with weight and well-being.

RESULTS

Path analysis suggested that self-criticism was significantly associated with decreased well-being, both directly and indirectly, mediated by increased negative and decreased positive weight-related affect. Self-reassurance had a stronger association with increased well-being by predicting lower negative and increased positive weight-related affect. All effects were significant at p < 0.001.

CONCLUSION

Self-criticism and self-reassurance were related to well-being in participants attempting to manage their weight, both directly and through their impact on weight-related affect. The positive association between self-reassurance and well-being was stronger than the negative association between self-criticism and well-being. Supporting the development of self-reassuring competencies in weight management programmes may improve weight-related affect and well-being.

Increasing Children's Voluntary Physical Activity Outside of School Hours Through Targeting Social Cognitive Theory Variables

INTRODUCTION

Volume of moderate-to-vigorous physical activity completed during the elementary school day is insufficient, and associated with health risks. Improvements in theory-based psychosocial factors might facilitate increased out-of-school physical activity.

METHODS

A behaviorally based after-school care protocol, Youth Fit 4 Life, was tested for its association with increased voluntary, out-of-school physical activity and improvements in its theory-based psychosocial predictors in 9- to 12-year-olds.

RESULTS

Increases over 12 weeks in out-of-school physical activity, and improvements in self-regulation for physical activity, exercise self-efficacy, and mood, were significantly greater in the Youth Fit 4 Life group (n = 88) when contrasted with a typical care control group (n = 57). Changes in the 3 psychosocial variables significantly mediated the group-physical activity change relationship (R(2) = .31, P < .001). Change in self-regulation was a significant independent mediator, and had a reciprocal relationship with change in out-of-school physical activity. In the Youth Fit 4 Life group, occurrence of 300 min/wk of overall physical activity increased from 41% to 71%.

CONCLUSIONS

Targeting theory-based psychosocial changes within a structured after-school care physical activity program was associated with increases in children's overall time being physically active. After replication, large scale application will be warranted.

Changes in self-efficacy for exercise and improved nutrition fostered by increased self-regulation among adults with obesity

Behavioral theory suggests that treatments that increase participants' use of self-regulatory skills and/or their feelings of ability (self-efficacy) will improve exercise and nutrition behaviors. In addition, psychosocial factors associated with increased exercise may carry over to improved eating. Self-regulation might enhance self-efficacy through feelings of ability to manage barriers to maintaining weight-loss behaviors. Sedentary adults with severe or morbid obesity (M age = 43 years; M BMI = 40.1 kg/m(2)) participated in a 6-month study within a community-based YMCA center. We randomly assigned participants to one of the two groups that incorporated the same cognitive-behavioral support of exercise paired with methods for controlled, healthy eating emphasizing either (a) self-efficacy (n = 138), or (b) self-regulation (n = 136) methods. Mixed model repeated measures ANOVAs indicated significant improvements in exercise- and eating-related self-regulation over 3 months, and exercise- and eating-related self-efficacy over 6 months. The Self-Regulation Treatment Group demonstrated greater improvements in self-regulation for eating and fruit and vegetable intake than the Self-Efficacy Group. Regression analyses indicated that for both exercise and eating, self-regulation change significantly predicted self-efficacy change. In separate equations, changes in exercise and fruit and vegetable intake mediated those relationships, and change in self-efficacy and the corresponding behavioral changes demonstrated reciprocal, mutually reinforcing, relationships. There was evidence of carry-over, or generalization, of both self-regulation and self-efficacy changes from an exercise context to an eating context. We discussed findings in terms of leveraging self-regulation to improve self-efficacy, and provide a rationale for why exercise is the strongest predictor of success with weight loss. Results may be used to inform future behavioral weight-management treatments through improved knowledge of relationships among theoretically derived psychosocial factors.

Psychosocial predictors of decay in healthy eating and physical activity improvements in obese women regaining lost weight: translation of behavioral theory into treatment suggestions

Regain of lost weight is a universal problem for behavioral treatments. An increased understanding of theory-based psychosocial predictors of decay in behavioral correlates of weight loss might improve treatments. Data were derived from a previous weight loss investigation of 110 women with obesity. A subsample from the experimental treatment who lost ≥3 % body weight and regained at least one third of that over 24 months (N = 36) was assessed. During months 6 through 24, there were unfavorable changes in behavioral (fruit/vegetable and sweet intake; physical activity) and psychosocial variables. Mood change predicted change in fruit/vegetable and sweet intake, with emotional eating change mediating the latter relationship. Change in self-regulation predicted changes in sweet and fruit/vegetable intake and physical activity, with self-efficacy mediating the self-regulation-fruit/vegetable intake and self-regulation-physical activity relationships. Findings suggest that after treatment-induced weight loss, addressing indicated theory-based psychosocial variables might mitigate decay in behavioral predictors of healthier weight.

Pathways between BMI and adherence to weight management in adolescence

BACKGROUND

In order to understand the mechanisms involved in how overweight adolescents adhere to weight management and perceive its benefits, a few variables have been identified, namely, body mass index (BMI), body self-esteem (BSE) and positive perspective of life (PPL).

METHODS

In a sample of 112 adolescents, we investigated whether BMI would predict adolescents' self-efficacy/adherence (SEA) to weight management and perception of its benefits. A structural equation modeling approach was chosen. We hypothesized that perceived quality of life (PQL) would mediate the relationships between BMI and SEA and between BMI and perception of benefits (PB).

RESULTS

The results suggested that BMI is not directly associated with SEA and PB. However, PQL was identified as a mediator between BMI and SEA and PB.

CONCLUSION

These findings bring important implications for understanding overweight adolescents' adherence to weight management. There is evidence that adolescents' adherence to weight management and PB are not predicted by their BMI. However, it has been shown that PQL mediates this process. For a long time, health professionals have been too focused on BMI. Time has come to be more focused on quality of life and how to improve it.

Improved eating behaviours mediate weight gain prevention of young adults: moderation and mediation results of a randomised controlled trial of TXT2BFiT, mHealth program

BACKGROUND

Explanatory evaluation of interventions for prevention of weight gain is required beyond changes in weight, to determine for whom the intervention works and the underlying mechanisms of change. It was hypothesised that participant characteristics moderate intervention effect on weight change and improved eating and physical activity behaviours during the 3-month program mediate the relationship between intervention and weight.

METHODS

In our randomised controlled trial, young adults at risk of weight gain (n = 250) were assigned either to an intervention group that received a 3-month mHealth (TXT2BFiT) program with 6-month maintenance or to a control group. Data were collected via online self-report surveys. Hypothesised moderators and mediators of the intervention effect on weight were independently assessed in PROCESS macro models for 3 and 9-month weight change.

RESULTS

Males (P = 0.01), mid-20s age group (P = 0.04), and higher income earners (P = 0.02) moderated intervention effects on weight change at 3-months and males only at 9-months (P = 0.02). Weight change at 3 (-1.12 kg) and 9-months (-1.38 kg) remained significant when 3-month nutrition and physical activity behaviours were specified as mediators (P <0.01 and P = 0.01 respectively). Indirect paths explained 39% (0.72/1.85 kg) and 40 % (0.92/2.3 kg) of total effect on weight change at 3 and 9-months respectively. Increased vegetable intake by intervention group at 3-months accounted for 19 and 17% and decreased sugar-sweetened beverages accounted for 8 and 13% of indirect weight change effects at 3 and 9-months respectively.

CONCLUSIONS

TXT2BFiT was effective for both young men and women. Small sustained behavioural changes, including increased vegetable intake and decreased sugar-sweetened beverages consumption significantly mediated the intervention's effects on weight change. Improved eating behaviours and increased physical activity accounted for approximately 40% of the weight change.

TRIAL REGISTRATION

The trial is registered with the Australian New Zealand Clinical Trials Registry ( ACTRN12612000924853 ).

[Success in maintaining weight loss in Portugal: the Portuguese Weight Control Registry]

The scope of this article is to describe the Portuguese Weight Control Registry (PWCR) methodology and the participants currently enrolled specifically with respect to their individual and family weight history, previous weight loss attempts, and psychosocial characteristics. One hundred and ninety-eight adults (age: 39.7±11.1 years; BMI: 26.0±3.9 kg/m2), 59% women, filled out a questionnaire about demographics, health-related behaviors and motivation, and methods and strategies used to lose and/or maintain weight loss. Participants reported an average weight loss of 17.4 kg for an average of 29 months. Concerning the number of weight loss attempts, 73% of participants reported a maximum of three attempts of going on a diet, and 34% indicated only one attempt to lose weight in the past. The PWCR now features a considerable number of successful long-term weight loss maintainers in Portugal. Participants will be followed over the next years to learn about their characteristics and weight loss strategies in further detail, as well as to identify predictors of continued weight loss maintenance.

Weight Loss and the Prevention of Weight Regain: Evaluation of a Treatment Model of Exercise Self-Regulation Generalizing to Controlled Eating

CONTEXT

For decades, behavioral weight-loss treatments have been unsuccessful beyond the short term. Development and testing of innovative, theoretically based methods that depart from current failed practices is a priority for behavioral medicine.

OBJECTIVE

To evaluate a new, theory-based protocol in which exercise support methods are employed to facilitate improvements in psychosocial predictors of controlled eating and sustained weight loss.

METHODS

Women with obesity were randomized into either a comparison treatment that incorporated a print manual plus telephone follow-ups (n = 55) or an experimental treatment of The Coach Approach exercise-support protocol followed after 2 months by group nutrition sessions focused on generalizing self-regulatory skills from an exercise support to a controlled eating context (n = 55). Repeated-measures analysis of variance contrasted group changes in weight, physical activity, fruit and vegetable intake, mood, and exercise- and eating-related self-regulation and self-efficacy over 24 months. Regression analyses determined salient interrelations of change scores over both the weight-loss phase (baseline-month 6) and weight-loss maintenance phase (month 6-month 24).

RESULTS

Improvements in all psychological measures, physical activity, and fruit and vegetable intake were significantly greater in the experimental group where a mean weight loss of 5.7 kg (6.1% of initial body weight) occurred at month 6, and was largely maintained at a loss of 5.1 kg (5.4%) through the full 24 months of the study. After establishing temporal intervals for changes in self-regulation, self-efficacy, and mood that best predicted improvements in physical activity and eating, a consolidated multiple mediation model suggested that change in self-regulation best predicted weight loss, whereas change in self-efficacy best predicted maintenance of lost weight.

CONCLUSIONS

Because for most participants loss of weight remained greater than that required for health benefits, and costs for treatment administration were comparatively low, the experimental protocol was considered successful. After sufficient replication, physician referral and applications within health promotion and wellness settings should be considered.

Health-related quality of life in two randomized controlled trials of phentermine/topiramate for obesity: What mediates improvement?

PURPOSE

Phentermine/topiramate combination therapy resulted in significant weight loss and improvements in cardiometabolic risk factors in patients with obesity/overweight in two published 56-week randomized, placebo-controlled trials (EQUIP and CONQUER). The purpose of the current study was to examine whether phentermine/topiramate is also associated with greater improvements in health-related quality of life (HRQOL) and whether HRQOL improvements are solely attributable to weight reduction.

METHODS

Patients in EQUIP (n = 751) had a body mass index (BMI) ≥ 35 with no obesity-related comorbidity. Patients in CONQUER (n = 1623) had a BMI ≥ 27 and ≤ 45 and at least two obesity-related comorbid conditions. HRQOL was assessed with Impact of Weight on Quality of Life-Lite (IWQOL-Lite) and Medical Outcomes Study Short Form (SF-36) (CONQUER only).

RESULTS

Significant improvements in both obesity-specific and physical HRQOL were observed at 56 weeks in both trials (p < .0001). In EQUIP, BMI reduction fully mediated improvements in IWQOL-Lite total score (p < .0001). In CONQUER, both BMI reduction (all p values < .0001) and change in depressive symptoms (all p values < .025) were significant mediators of improved IWQOL-Lite total score and SF-36 Physical Component Summary score. Gender, psychiatric history, and baseline triglycerides moderated these relationships.

CONCLUSIONS

Both trials demonstrated that treatment with phentermine/topiramate improved HRQOL compared with placebo. Although reduction in BMI accounted for the majority of improvements in obesity-specific and physical HRQOL, decrease in depressive symptoms was also a significant mediator. Results highlight the predominance of weight reduction as a key factor in improving HRQOL in obesity.

Reciprocal effects of exercise and nutrition treatment-induced weight loss with improved body image and physical self-concept

Improvements in self-image and mood are often reported as outcomes of obesity interventions. However, they may also concurrently influence weight loss, suggesting a reciprocal effect. Although previously reported for overweight women, such relationships were untested in morbidly obese women whose psychosocial responses to treatment may be different, and health-risks greater. Women (N = 161, Meanage = 42 years) with morbid obesity (MeanBMI = 45.1 kg/m(2)) participated in a 6-month, behaviorally based physical activity and nutrition treatment. Significant within-group improvements in weight-loss behaviors (physical activity and eating), weight, body satisfaction, physical self-concept, and depression were found. After controlling for age, mediation analyses indicated that, as a result of the treatment, weight loss was both an outcome and mediator of improvements in body-areas satisfaction and physical self-concept (reciprocal effects), but not depression. Results replicated findings from women with lower degrees of overweight, and suggested that weight-loss treatments emphasize changes in self-perception.

Theory-based psychosocial factors that discriminate between weight-loss success and failure over 6 months in women with morbid obesity receiving behavioral treatments

PURPOSE

To improve success rates of behavioral weight-loss treatments, a better understanding of psychosocial factors that discriminate between weight-loss success and failure is required. The inclusion of cognitive-behavioral methods and manageable amounts of exercise might induce greater improvements than traditional methods of education in healthy eating practices.

METHODS

Women with morbid obesity [body mass index (BMI) ≥40 kg/m(2)] were recruited for a treatment of supported exercise paired with either a cognitive-behavioral or an educational approach to eating change over 6 months. They were classified as either successful with (i.e., at least 5 % loss; n = 40) or failed at (no loss, or weight gain; n = 43) weight loss. Discriminate function analysis incorporated theory-based models of 1 (self-efficacy), 5 (self-efficacy, self-regulation, mood, physical self-concept, body satisfaction), and 3 (self-efficacy, self-regulation, mood) psychosocial predictors at both month 6, and change from baseline-month 6.

RESULTS

All three models significantly discriminated weight-loss success/failure (66, 88, and 87 % for success; and 81, 87, and 88 % for failure, respectively). Self-regulation had the strongest correlations within the multi-predictor models (0.90-0.96), and all variables entered were above the standard of 0.30 set for relevance. Participants in the cognitive-behavioral nutrition group demonstrated significantly greater improvements in all psychosocial variables and success with weight loss. Completing at least two sessions of exercise per week predicted success/failure with weight loss better than overall volume of exercise.

CONCLUSIONS

New and relevant findings regarding treatment-induced psychosocial changes might be useful in the architecture of more successful behavioral weight-loss interventions.

Body image change in obese and overweight persons enrolled in weight loss intervention programs: a systematic review and meta-analysis

To report the results of a systematic review and meta-analysis examining whether weight loss interventions improve body image in obese/overweight individuals. Medline, Current Contents, and the Cochrane database were searched to identify studies involving obese/overweight adults who were enrolled in weight loss interventions in which body image was quantitatively assessed. Outcomes assessed were changes in body shape concern, body size dissatisfaction, and body satisfaction (intervention vs comparator/control group). Seven studies were included in the systematic review (4 in the meta-analysis). All but 1 study involved female participants only. The type of weight loss intervention varied between studies as did the type of control/comparator group. In 3 studies, there was no significant difference in body image outcomes, whereas in 4 studies, improvement in body image was significantly more pronounced in the intervention vs the control/comparator group. Meta-analysis revealed that improvements in body shape concern (standardized difference: -0.52; 95% confidence interval [CI]: -1.04 to 0.00), body size dissatisfaction (standardized difference: -0.66; 95% CI: -0.88 to -0.45), and body satisfaction (standardized difference: 0.74; 95% CI: 0.09 to 1.38) significantly favored the intervention over the comparator/control group (P<0.05). The results of this systematic review/meta-analysis lend support to the notion that weight loss interventions may improve body image. This is a noteworthy finding that has clear clinical applicability because body image affects psychological well-being and the ability of an individual to maintain weight loss. Future research should determine which weigh loss interventions are associated with optimal improvements in body image and maintenance of weight loss.

Successful behavior change in obesity interventions in adults: a systematic review of self-regulation mediators

BACKGROUND

Relapse is high in lifestyle obesity interventions involving behavior and weight change. Identifying mediators of successful outcomes in these interventions is critical to improve effectiveness and to guide approaches to obesity treatment, including resource allocation. This article reviews the most consistent self-regulation mediators of medium- and long-term weight control, physical activity, and dietary intake in clinical and community behavior change interventions targeting overweight/obese adults.

METHODS

A comprehensive search of peer-reviewed articles, published since 2000, was conducted on electronic databases (for example, MEDLINE) and journal reference lists. Experimental studies were eligible if they reported intervention effects on hypothesized mediators (self-regulatory and psychological mechanisms) and the association between these and the outcomes of interest (weight change, physical activity, and dietary intake). Quality and content of selected studies were analyzed and findings summarized. Studies with formal mediation analyses were reported separately.

RESULTS

Thirty-five studies were included testing 42 putative mediators. Ten studies used formal mediation analyses. Twenty-eight studies were randomized controlled trials, mainly aiming at weight loss or maintenance (n = 21). Targeted participants were obese (n = 26) or overweight individuals, aged between 25 to 44 years (n = 23), and 13 studies targeted women only. In terms of study quality, 13 trials were rated as "strong", 15 as "moderate", and 7 studies as "weak". In addition, methodological quality of formal mediation analyses was "medium". Identified mediators for medium-/long-term weight control were higher levels of autonomous motivation, self-efficacy/barriers, self-regulation skills (such as self-monitoring), flexible eating restraint, and positive body image. For physical activity, significant putative mediators were high autonomous motivation, self-efficacy, and use of self-regulation skills. For dietary intake, the evidence was much less clear, and no consistent mediators were identified.

CONCLUSIONS

This is the first systematic review of mediational psychological mechanisms of successful outcomes in obesity-related lifestyle change interventions. Despite limited evidence, higher autonomous motivation, self-efficacy, and self-regulation skills emerged as the best predictors of beneficial weight and physical activity outcomes; for weight control, positive body image and flexible eating restraint may additionally improve outcomes. These variables represent possible targets for future lifestyle interventions in overweight/obese populations.

Temporal aspects of psychosocial predictors of increased fruit and vegetable intake in adults with severe obesity: mediation by physical activity

Effective and reliable obesity treatments are lacking because of a poor understanding of the health behavior change process. Community-based organizations with the capacity to train existing staff members are particularly well-positioned to implement evidence-based treatment protocols to impact obesity-related behaviors such as unhealthy eating and lack of physical activity. The aim of this study was to assess temporal aspects of psychosocial predictors (self-regulation, mood, and self-efficacy) on increased fruit and vegetable intake in adults with severe obesity, while also accounting for mediation by physical activity volume. A 6-month, randomized field investigation was conducted. Severely obese adults volunteered for behavioral support of physical activity coupled with nutrition education (n = 73) or cognitive-behavioral methods for nutrition change (n = 71). Improvements in self-regulation, mood, self-efficacy, fruit and vegetable intake (FV), and physical activity (PA) were significant, with significantly greater self-regulation at month 6 for the cognitive-behavioral group. Increase in FV was predicted by changes in the above psychosocial variables over 6 months, with mood change over 3 months also a significant predictor. Change in PA mediated the above relationships, with a reciprocal effect between changes in PA and FV. Findings have implications for the large-scale behavioral treatment of obesity.

Behavioural support of a proposed neurocognitive connection between physical activity and improved eating behaviour in obese women

PROBLEM

An explanation of the association between physical activity and improved eating behaviours has recently been posited via the effect of physical activity on executive functions of the brain resulting in a reduction in the hedonic drive to overeat. Decomposition and clarification of embedded relationship through a behavioural/psychological framework was sought.

METHODS

Changes in theory-based psychosocial factors over 26 weeks were tested with 134 severely obese women (age 41.7±10.4 years) initiating a physical activity support treatment. Mediation and reciprocal effects analyses incorporating these changes were then computed.

RESULTS

Significant improvements in mood, self-regulation for eating, and self-efficacy for controlled eating were found. Emanating from mood change, a reciprocal relationship between changes in the self-regulation and self-efficacy measures was found. Thus, each factor reinforced the other's change.

CONCLUSION

Findings suggest a convergence of neurocognitively and behaviourally based explanations of the relations of physical activity and controlled eating. Implications for behavioural weight-loss theory and treatments were suggested.

Compliance to step count and vegetable serve recommendations mediates weight gain prevention in mid-age, premenopausal women. Findings of the 40-Something RCT

The 40-Something RCT aimed to determine if a 12-month health professional-led intervention could modify diet and physical activity behaviour for obesity prevention, in 44-50 year old, non-obese (BMI = 18.5-29.9 kg/m(2)) premenopausal women. Women were monitored for an additional 12 months to determine if effects could be maintained. This paper aimed to explore dietary and physical activity behavioural mediators hypothesised to be causally associated with weight change. Fifty-four women were randomised to a Motivational Interviewing Intervention (MI) (n = 28; five health professional consultations) or a Self-Directed Intervention (n = 26; written advice). Compliance to 10 study recommendations was measured at three months by a four-day weighed food and physical activity record including pedometer-measured step counts, self-reported exercise minutes and sitting time. The 10 compliance scores were independently assessed in mediation models for 12- and 24-month weight change. The MI effect on step count was an increase of 0.99 points on the 10-point compliance scale (p ≤ 0.01). This MI effect on step count significantly mediated the 12 and 24 month effect on weight (12 months AB = -0.74, 95%CI = -1.95, -0.14; 24 months AB = -1.06, 95% CI = -2.56, -0.36), accounting for 37.23% and 53.79% of the effect, respectively. The MI effect on vegetable serves was an increase of 1.50 points on the compliance scale (p = 0.02). The MI effect on vegetable compliance significantly mediated the effect on weight at 24 months (AB = -0.54, 95% CI = -1.50, -0.04), accounting for 24.92% of the effect. The remaining eight dietary and physical activity compliance scores did not significantly mediate weight loss. Encouraging women to take 10,000 steps and eat five vegetable serves per day may be a promising strategy to achieve long-term weight control at mid-life.

Influence of specific individual and environmental variables on the relationship between body mass index and health-related quality of life in overweight and obese adolescents

PURPOSE

Overweight and obese adolescents are at risk for low health-related quality of life (HRQOL). We examined the role of individual- and environmental-level variables on the relationship between body mass index (BMI kg/m(2)) and HRQOL in adolescents.

METHODS

Linear regressions were performed to conduct mediation and moderation analyses on the relationship between BMI and HRQOL in overweight and obese adolescents (N = 205). HRQOL was measured by the Pediatric Quality of Life Inventory. Hypothesized mediators included depression, measured by the Center for Epidemiologic Studies Depression Scale; body image, measured by the gender-specific body dissatisfaction subscale of the Eating Disorder Inventory; and self-esteem, measured by the Rosenberg Self-Esteem Scale. Mediation was assessed using Baron and Kenny's approach and Sobel's test of indirect effects. Anglo-acculturation, measured by the Short Acculturation Scale for Hispanics-Youth, and environmental perception, measured by parent-proxy report of the Neighborhood Environment Walkability Scale, were hypothesized moderators.

RESULTS

Body image mediated the relationship between BMI and HRQOL (b = -0.34, SE = 0.17, adj R (2) = 0.19, p = .051), and self-esteem was a partial mediator (b = -0.37, SE = 0.17, adj R (2) = 0.24, p = .027). Sobel's test confirmed these results (p < .05). No significant moderation effects were found.

CONCLUSIONS

The finding that individual-level factors, such as body image and self-esteem, influence the relationship between BMI and HRQOL while environmental factors, such as neighborhood environment and acculturation, do not extends previous research. The finding that body image and self-esteem partially mediate this relationship presents new areas to investigate in interventions that address BMI in youth.

Bi-Directional Relationship Between Self-Regulation and Improved Eating: Temporal Associations With Exercise, Reduced Fatigue, and Weight Loss

Severely obese men and women (body mass index ≥ 35 ≤ 55 kg/m(2); M(age) = 44.8 years, SD = 9.3) were randomly assigned to a 6-month physical activity support treatment paired with either nutrition education (n = 83) or cognitive-behavioral nutrition (n = 82) methods for weight loss. Both groups had significant improvements in physical activity, fatigue, self-regulation for eating, and fruit and vegetable intake. Compared to those in the nutrition education group, participants in the behavioral group demonstrated greater overall increases in fruit and vegetable intake and physical activity. These group differences were associated with changes that occurred after Month 3. Increased physical activity predicted reduced fatigue, β = -.19, p =.01. A reciprocal relationship between the mediators of that relationship, which were changes in self-regulation and fruit and vegetable intake, was identified. There was significantly greater weight loss over six months in the behavioral nutrition group when contrasted with the nutrition education group. Self-regulation for eating and fruit and vegetable intake were significant predictors of weight loss over both three and six months. Findings enabled a better understanding of psychosocial effects on temporal aspects of weight loss and may lead to more effective behavioral treatments for weight loss.

Managing paediatric obesity: a multidisciplinary intervention including peers in the therapeutic process

BACKGROUND

Adolescent obesity epidemic is one of the major health priorities as it tracks into adult life. There is widespread need for new creative strategies and lifestyle programs. This study was designed to investigate the possible impact of including peers on the weight management program and assess the long-run adherence to behaviour change, with a potential positive impact on body mass index, body composition, and physical activity. Peer influence is major at this age and it is expected that adolescents will be better motivated and engaged in the behaviour changes when they are accompanied by their friends.

METHODS/DESIGN

The study is a non-randomised, non-blinded controlled trial, including two groups: 1) Comparison group (n = 35), which will receive a 12 month standard treatment at the hospital setting plus a weekly interactive and physical activity session; 2) Experimental group (n = 99), which will receive the standardized treatment at the hospital plus a weekly session together with a peer of their choice. The sample size calculations for the primary outcomes showed that we will have power to detect effect sizes of 0.25. Measures include: a) Dual-energy x-ray absorptiometry (for body composition assessment); b) Anthropometric evaluations; c) Assessment of physical activity levels by accelerometers; d) Psychosocial mediators (motivation and peer support) assessed with a package of psychometric questionnaires; and e) Outcomes (quality of life and well-being).

DISCUSSION

Adolescence is a crucial period for the development of a healthy lifestyle, especially among those who reach this age with an obesity condition. Obesity management programs directed to adolescents are often an adopted version of programs developed for children, most of them with a strong focus on the family, or an adopted version of adult programs, not recognizing the specificities of this age group. This study is designed taking into account the unique characteristics of this life-cycle stage, with the main objective of testing an innovative treatment for adolescent obesity.

TRIAL REGISTRATION

This trial is registered in the clinicaltrials.gov with the number NCT02024061.

Reciprocal effects of treatment-induced increases in exercise and improved eating, and their psychosocial correlates, in obese adults seeking weight loss: a field-based trial

BACKGROUND

A better understanding of interrelations of exercise and improved eating, and their psychosocial correlates of self-efficacy, mood, and self-regulation, may be useful for the architecture of improved weight loss treatments. Theory-based research within field settings, with samples possessing high probabilities of health risks, might enable rapid application of useful findings.

METHODS

Adult volunteers with severe obesity (body mass index [BMI] 35-50 kg/m²; age = 43.0 ± 9.5 y; 83% female) were randomly assigned to six monthly cognitive-behavioral exercise support sessions paired with either group-based nutrition education (n = 145) or cognitive behavioral methods applied to improved eating (n = 149). After specification of mediation models using a bias-corrected bootstrapping procedure, a series of reciprocal effects analyses assessed: a) the reciprocal effects of changes in exercise and fruit and vegetable intake, resulting from the treatments, b) the reciprocal effects of changes in the three psychosocial variables tested (i.e. self-efficacy, mood, and self-regulation) and fruit and vegetable change, resulting from change in exercise volume, and c) the reciprocal effects of changes in the three psychosocial variables and exercise change, resulting from change in fruit and vegetable intake.

RESULTS

Mediation analyses suggested a reciprocal effect between changes in exercise volume and fruit and vegetable intake. After inclusion of psychosocial variables, also found were reciprocal effects between change in fruit and vegetable intake and change in mood, self-efficacy for controlled eating, and self-regulation for eating; and change in exercise volume and change in mood and exercise-related self-regulation.

CONCLUSION

Findings had implications for behavioral weight-loss theory and treatment. Specifically, results suggested that treatments should focus upon, and leverage, the transfer effects from each of the primary weight-loss behaviors (exercise and healthy eating) to the other. Findings on psychosocial correlates of these behavioral processes may also have practical applications.