Physical activity and weight loss: does prescribing higher physical activity goals improve outcome?

Causal Relationship Between Physical Activity and Body Weight: A Maximum Likelihood Treatment Effect Model Approach Using Australian Longitudinal Data

BACKGROUND

More than two-thirds of Australians are overweight. Existing research based on non-experimental data has primarily established associations, rather than causal inferences, between physical activity (PA) and body mass index (BMI). PA and BMI likely affect each other, a reciprocal interplay most studies overlook. We investigate the causal relationship between PA and BMI using a quasi-experimental approach to overcome reverse causality bias.

METHOD

A maximum likelihood treatment effect model, a quasi-experimental method, was employed. Data was from an observational longitudinal dataset of 130,397 observations with 19,677 unique individuals aged 15-64 (52% are females) from the Household, Income, and Labour Dynamics in Australia survey 2006-2019. We first tested for the reverse relationships (whereby overweight limits PA) before estimating the effect of PA on BMI.

RESULTS

The first-stage modelling results showed that overweight and obese adults are less likely to engage in PA, as are those resource constrained (time or socioeconomically). In the second modelling stage, there was a clear and significant effect of PA on BMI. Being physically active more than three times a week led to a 2.55-point reduction in BMI (p < 0.001). For women, this effect was more pronounced, with a 2.92-point reduction (p < 0.001).

CONCLUSION

This study leverages existing longitudinal data to provide causal estimates of PA on BMI-finding that PA reduces BMI, particularly for women. As many individuals face resource constraints, campaigns to promote behavioural change need to be nuanced and shift some of the responsibility for physically activity from individuals to policy and organizational reforms.

Biopsychosocial Effects of a Conventional Exercise Program and Culturally Relevant Activities in Older Women From Mozambique

AIM

This randomized controlled trial compared the effects of a Conventional Exercise Program (CEP) and Culturally Relevant Activities (CRA) on body mass, cardiovascular risk, functional fitness (strength, flexibility, cardiorespiratory fitness, and agility), self-efficacy, and self-esteem in older women dwelling in Mozambique.

METHODS

Fifty-seven women (67 [7] y) underwent 60-minute sessions of CEP (n = 28) or CRA (n = 29) performed 3 days per week for 12 weeks. CRA included Mozambican traditional dances and games (intensity corresponding to scores 3-4 of BORG-CR10 scale), and CEP included 20-minute stationary cycling (65%-75% heart rate reserve) and a resistance training circuit (8 exercises, 15-repetition maximum).

RESULTS

CEP and CRA (P < .05) showed increased percent fat (3.4% and 5.3%), waist circumference (3.3% and 5.8%), and cardiorespiratory fitness (14.4% and 9.4%), and decreased triglycerides (-20.0% and -77.8%). In CEP (P < .05), body mass (2.9%), body mass index (3.2%), and high-density lipoprotein (10.0%) increased, while glycemia (-4.8%) and total cholesterol (-9.8%) decreased. Blood pressure slightly increased in CEP (6.2%, P > .05) and CRA (4.3%, P < .05). Self-efficacy and self-esteem increased to similar levels in both groups (15%, P < .05).

CONCLUSIONS

CEP and CRA were capable to improve biopsychosocial health-related variables in Mozambican older women. Culturally referenced PA interventions should be considered as an alternative in African countries.

Obesity-induced and weight-loss-induced physiological factors affecting weight regain

Weight regain after successful weight loss resulting from lifestyle interventions is a major challenge in the management of overweight and obesity. Knowledge of the causal mechanisms for weight regain can help researchers and clinicians to find effective strategies to tackle weight regain and reduce obesity-associated metabolic and cardiovascular complications. This Review summarizes the current understanding of a number of potential physiological mechanisms underlying weight regain after weight loss, including: the role of adipose tissue immune cells; hormonal and neuronal factors affecting hunger, satiety and reward; resting energy expenditure and adaptive thermogenesis; and lipid metabolism (lipolysis and lipid oxidation). We describe and discuss obesity-associated changes in these mechanisms, their persistence during weight loss and weight regain and their association with weight regain. Interventions to prevent or limit weight regain based on these factors, such as diet, exercise, pharmacotherapy and biomedical strategies, and current knowledge on the effectiveness of these interventions are also reviewed.

Increasing Physical Activity in Persons With Spinal Cord Injury With an eHealth-Based Adaptive Exercise Intervention: Protocol for a Sequential Multiple Assignment Randomized Trial

BACKGROUND

Participating in an adequate amount of physical activity to acquire health benefits is challenging for people with spinal cord injury (SCI) due to personal and logistic barriers. Barriers in the built and social environments may include lack of transportation, lack of accessible facilities or programs, and lack of training among fitness personnel. Low self-efficacy, lack of self-regulation skills, and improper outcome expectations are examples of personal barriers. Current approaches to investigating physical activity programs in people with SCI have been limited to traditional "one-size-fits-all" design, which has yielded low adherence rates, high dropout rates, and participants not maintaining physical activity levels at follow-up.

OBJECTIVE

The primary aim of this study is to test the feasibility of a tele-exercise program that applies an adaptive intervention design for 30 adults with SCI, targeting increases in adherence to the exercise program and physical activity participation.

METHODS

The Sequential Multiple Assignment Randomized Trial for Home-based Exercise and Lifestyle Tele-Health (SMART-HEALTH) is a 12-week, home-based, movement-to-music (M2M) program. The goal of a SMART-designed study is to develop an adaptive intervention that modifies support provisions based on response levels. In SMART-HEALTH, 2 groups of participants will undergo 3-week and 6-week asynchronous M2M interventions in the first phase. Participants who did not achieve the desired adherence rate (≥95% of video watch minutes) will be rerandomized into M2M Live (switch) or individualized behavioral coaching (augmented with the asynchronous M2M program). The study will primarily assess rates of recruitment or enrollment, adherence and retention, timing to identify nonresponders, and scientific outcomes (eg, physical activity and exercise self-efficacy). The study will qualitatively evaluate the acceptability of the study using semistructured interviews among participants who complete the 12-week intervention.

RESULTS

Recruitment procedures started in June 2022. All data are expected to be collected by September 2023. Full trial results are expected to be published by March 2024. Secondary analyses of data will be subsequently published. Results will include exercise adherence rates; changes in self-reported physical activity levels and blood pressure; and changes in secondary conditions including pain, sleep, and fatigue. Thematic analysis of semistructured interviews will include results on participant enjoyment and acceptability of SMART-HEALTH and inform modifications for future delivery of the program.

CONCLUSIONS

This study will strengthen our understanding of the potential benefits of the tele-exercise intervention for people with SCI and build upon adaptive intervention design and its delivery strategies that aim to increase adoption and sustainable exercise behavior. This pilot trial will inform future SMART-designed studies and provide new and innovative strategies for investigating intervention effects on physical activity behavior in the SCI population.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04726891; https://classic.clinicaltrials.gov/ct2/show/NCT04726891.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/47665.

The Association Between Goal Setting and Weight Loss: Prospective Analysis of a Community Weight Loss Program

BACKGROUND

Goal setting aids health-related behavior changes; however, the influence of different types of goals on weight loss remains unclear.

OBJECTIVE

We aimed to investigate the association of 3 aspects of goal setting with weight and program dropout over a 24-week period.

METHODS

This study was a prospective longitudinal analysis of participants in a 12-week digital behavioral weight loss program. Weight and engagement data for eligible participants (N=36,794) were extracted from the database. Eligible participants were adults in the United Kingdom who had enrolled in the program, had a BMI ≥25 kg/m², and a weight reading recorded at baseline. Three aspects of goal setting were self-reported at enrollment: weight loss motivation (appearance, health, fitness, or self-efficacy), overall goal preference (low, medium, or high), and percentage weight loss goal (<5%, 5%-10%, or >10%). Weight was measured at 4, 12, and 24 weeks. Mixed models for repeated measures were used to explore the association between goals and weight across the 24-week period. To measure sustained weight change, the primary outcome was weight at 24 weeks. We explored dropout rates over the 24-week period by goal and whether engagement mediated the association between goals and weight loss.

RESULTS

Of the 36,794 participants (mean 46.7, SD 11.1 years; 33,902/36,794, 92.14% female) included in the cohort, 13.09% (n=4818) reported weight at 24 weeks. Most participants set goals of 5%-10% weight loss (23,629/36,794, 64.22%), but setting goals for >10% was associated with greater weight loss (mean difference 5.21 kg, 95% CI 5.01-5.41; P<.001). There was no difference between goals of 5%-10% and <5% (mean difference 0.59 kg, 95% CI 0.00-1.18; P=.05). Appearance was the most prevalent motivational factor (14,736/36,794, 40.05%), but health and fitness were associated with greater weight losses (mean difference health vs appearance 1.40 kg, 95% CI 1.15-1.65; P<.001 and mean difference fitness vs appearance 0.38 kg, 95% CI 0.05-0.70; P=.03). Goal preference had no association with weight. Engagement was an independent predictor of weight loss but not a mediator of the effect of goal setting. At 24 weeks, those who set goals of >10% were less likely to drop out compared with 5%-10% goals (odds ratio [OR] 0.40, 95% CI 0.38-0.42; P<.001); those who liked to set overall high goals were more likely to drop out compared with medium goals (OR 1.20, 95% CI 1.11-1.29; P<.001); and those motivated by fitness or health were less likely to drop out compared with appearance (OR 0.92, 95% CI 0.85-0.995; P=.04 and OR 0.84, 95% CI 0.78-0.89; P<.001, respectively).

CONCLUSIONS

Setting higher weight loss goals and being motivated by health or fitness were associated with greater weight loss and lower likelihood of dropout. Randomized trials for setting these types of goals are required to confirm causality.

Effect of High-Intensity Interval Training vs. Moderate-Intensity Continuous Training on Fat Loss and Cardiorespiratory Fitness in the Young and Middle-Aged a Systematic Review and Meta-Analysis

OBJECTIVES

This systematic review is conducted to evaluate the effect of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on body composition and cardiorespiratory fitness (CRF) in the young and middle-aged.

METHODS

Seven databases were searched from their inception to 22 October 2022 for studies (randomized controlled trials only) with HIIT and MICT intervention. Meta-analysis was carried out for within-group (pre-intervention vs. post-intervention) and between-group (HIIT vs. MICT) comparisons for change in body mass (BM), body mass index (BMI), waist circumference (WC), percent fat mass (PFM), fat mass (FM), fat-free mass (FFM), and CRF.

RESULTS

A total of 1738 studies were retrieved from the database, and 29 studies were included in the meta-analysis. Within-group analyses indicated that both HIIT and MICT can bring significant improvement in body composition and CRF, except for FFM. Between-group analyses found that compared to MICT, HIIT brings significant benefits to WC, PFM, and VO_2peak.

CONCLUSIONS

The effect of HIIT on fat loss and CRF in the young and middle-aged is similar to or better than MICT, which might be influenced by age (18-45 years), complications (obesity), duration (>6 weeks), frequency, and HIIT interval. Despite the clinical significance of the improvement being limited, HIIT appears to be more time-saving and enjoyable than MICT.

The role of physical activity in the regulation of body weight: The overlooked contribution of light physical activity and sedentary behaviors

The role of physical activity (PA) in the regulation of body weight is still a major topic of debate. This may be because studies have essentially focused on the effects of moderate/vigorous PA (MVPA) on body weight while overlooking the other components of PA, namely, light-intensity PA (LPA, daily life activities) and sedentary behaviors (SB, too much sitting). In this review, we will (i) describe the history of changes in PA behaviors that occurred with modernization; (ii) review data from cross-sectional and longitudinal studies that examined the associations between PA, SB, and measures of obesity; (iii) review interventional studies that investigated the effects of changes in PA and SB on body weight and adiposity; and (iv) discuss experimental studies that addressed potential biological mechanisms underlying the effects of PA and SB on weight regulation. Overall recent findings support the importance of considering all components of PA to better understand the regulation of energy balance and suggest an important role for LPA and SB in addition to MVPA on body weight regulation. Longitudinal large-scale rigorous studies are needed to advance our knowledge of the role of PA/SB in combating the obesity epidemic.

A qualitative evaluation of a clinic versus home exercise rehabilitation program for adults with multiple sclerosis: The tele-exercise and multiple sclerosis (TEAMS) study

BACKGROUND

Substantial evidence supports therapeutic exercise for improving health and function in people with multiple sclerosis (MS). However, few studies have considered the patients' perspective.

OBJECTIVE

This study explored perspectives of adults with MS following participation in a 3-month clinic- and home-based exercise rehabilitation program.

METHODS

Twenty participants with MS were interviewed using a semi-structured interview guide on the design and implementation processes of the exercise programs as well as any perceived facilitators or barriers to exercise. Data analysis was conducted using a thematic analysis approach to generate themes from the transcribed interviews.

RESULTS

Key facilitators of exercise for people with MS included perceived improvements in physical health and function, activity participation, and psychosocial health. Mismatched level of exercise with their stage of post-diagnosis and/or functional ability and limited human interaction emerged as barriers to exercise.

CONCLUSIONS

Participation in the exercise program was a positive experience for people with MS. Despite the provision of a high level of adaptation and tailored exercise plan and delivery, self-directed exercise continued to present challenges for people with MS. Additionally, the importance of seeking cost-effective ways to maintain motivational support was implicit in participant responses. The findings provided an improved understanding of personal experiences and exercise perspectives that can inform future intervention strategies aimed at promoting sustained exercise participation.

A cluster-randomized controlled trial of automated internet weight-loss programs in primary care: Role of automated provider feedback

OBJECTIVE

Despite the high prevalence of obesity and associated health risks in the United States adult population, few primary care providers (PCPs) have time and training to provide weight-management counseling to their patients. This study aims to compare the effect of referral to a comprehensive automated digital weight-loss program, with or without provider email feedback, with usual care on weight loss in patients with overweight or obesity.

METHODS

A total of 550 adults (mean [SD], 51.4 [11.2] years, BMI = 35.1 [5.5] kg/m2 , 72.0% female) were enrolled through their PCPs (n = 31). Providers were randomly assigned to refer their patients to a 12-month internet weight-loss intervention only (IWL), the intervention plus semiautomated feedback from the provider (IWL + PCP), or to usual care (EUC). Weight was measured at baseline and at 3, 6, and 12 months.

RESULTS

Weight changes (mean [SE]) at 12 months were -0.92 (0.46), -3.68 (0.46), and -3.58 (0.48) kg in the EUC, IWL, and IWL + PCP groups, respectively. Outcomes were significantly different in EUC versus IWL and EUC versus IWL + PCP (p < 0.001), but not in IWL versus IWL + PCP.

CONCLUSIONS

Referral by PCPs to an automated weight-loss program holds promise for patients with obesity. Future research should explore ways to further promote accountability and adherence.

Survey of Belgian owners' perspectives on quality of life and difficulties during a weight-loss programme in obese cats

OBJECTIVES

The aims of this study were to determine owners' perception of their cats' quality of life (QoL), and whether there is a correlation with weight-loss variables, as well as to identify the main difficulties owners encounter during controlled weight loss in their obese cats.

METHODS

The study was carried out as an e-questionnaire survey addressed to owners of cats starting a weight-loss programme. The e-questionnaire was provided at a single time point after the conclusion of the study (24 weeks).

RESULTS

Nineteen completed questionnaires were included. Eighteen cats had a lower weight at the end of the weight-loss period, two of which had successfully reached their target weight. Mean weight loss was 13.84% body weight at a rate of 0.53% weight loss/week. Although the perceived QoL was not correlated with weight-loss variables (P >0.05), it increased over time, even in cats that did not reach their target weight, and was statistically correlated with increased activity (r = 0.73; P <0.01), mobility (r = 0.78; P <0.01) and play time (r = 0.61; P <0.01). The main difficulties encountered by owners were not giving (32%) or permitting the cat to eat extra food (26%). The main presumed difficulty for the cat was having its food decreased over time (53%). Most owners considered their cats happy (42%) and quite happy (53%) during the study, and no statistically significant correlations were found between the weight loss, food-seeking behaviour and stress parameters (P >0.05).

CONCLUSIONS AND RELEVANCE

Although several difficulties were encountered throughout the study, increased QoL and energy levels in their cats were noticed by owners. A positive perspective on weight-loss programmes is important to keep owners motivated and achieve the target weight in their cats. Furthermore, this survey provides insights into the perceived difficulties of weight-loss regimens in cats.

The Role of Physical Activity in Long-term Weight Loss: 36-month Results From a Randomized Controlled Trial

BACKGROUND

Physical activity (PA) may promote long-term weight loss, but facilitating high levels of PA in behavioral weight loss programs is challenging.

PURPOSE

This study reports the 36-month follow-up of a behavioral weight loss trial that tested the efficacy of increasing the emphasis on PA during treatment and using traditional or acceptance-based therapy (ABT) for this purpose. We also examined the extent to which long-term weight loss differed by PA pattern and tested if individual differences in eating behavior moderated this relationship.

METHODS

Participants (N = 320) were randomized to (1) standard behavioral weight loss treatment (BT), (2) BT with a focus on PA, or (3) ABT with a focus on PA. Weight loss and PA were measured at 24- and 36-month follow-up.

RESULTS

There were no differences between conditions in weight loss or PA at 24 or 36 months. Participants consistently engaging in high PA experienced the greatest weight losses. The positive impact of PA on weight loss was more pronounced among those with low emotional eating and those who believed that exercise did not affect their appetite.

CONCLUSIONS

Findings emphasize the difficulty of improving long-term PA among adults with overweight/obesity beyond what standard behavioral weight loss treatment achieves. This study highlights the need to develop new PA treatment strategies, and suggests that ABT for weight loss may be more effective when applied to eating behavior versus PA. Results also demonstrate the importance of addressing problematic eating behavior and cognitions to fully realize the benefits of PA for weight loss.

CLINICAL TRIAL INFORMATION

ClinicalTrials.gov identifier: NCT02363010.

The Multi-Caregiver Role and Its Relationship to Behavioral Adherence and Weight Among Treatment Engaged Black Women

PURPOSE

To examine the relationship between the multiple caregiver role and its perceived barriers to self-care on behavioral adherence in a weight loss intervention.

DESIGN

A secondary analysis of data from a behavioral weight loss intervention.

SETTING

The study was conducted in two cohorts from March 2016 to February 2017 at the University of North Carolina at Chapel Hill.

SUBJECTS

Eighty-one Black women with overweight/obesity (age = 48.4 ± 10.9 years [M ± SD], BMI = 36.4 ± 4.5 kg/m² [M ± SD]).

MEASURES

Identification with the multiple caregiver role and barriers was assessed with the Multiple Caregiving Measurement Instrument. Weight was measured with a digital scale and height with a stadiometer. The Block food frequency questionnaire evaluated dietary intake. Moderate-to-vigorous physical activity (MVPA) was measured objectively with an accelerometer. Study adherence was measured by session attendance, self-weighing, and self-monitoring (diet and physical activity) frequency.

ANALYSIS

Generalized linear models were used to examine the relationship between the multiple caregiver scales and the outcomes of interest, controlling for study arm, cohort, and income. Chi-square tests tested correlations.

RESULTS

Greater identification with the multiple caregiver role was associated with decreased session attendance (β = -.56 [SE = .27], P < .05) and a trend towards weight gain (β = .36, [SE = .19], P = .07). Greater multiple caregiver barriers score predicted a decrease in fruit/vegetable intake (β = -.17 [SE = .07], P < .05). All regression results are unstandardized. Negative correlations between multiple caregiver barriers and MVPA (r = -.24, P = .06) and daily self-weighing (r = -.19, P = .10) approached significance.

CONCLUSIONS

Participants' identification with multiple caregiving role and barriers can reduce adherence, behavior and weight change. Interventions to address Black women's multiple roles and barriers during weight loss are needed to maximize outcomes.

Facilitators, Barriers, and Structural Determinants of Physical Activity in Nulliparous Pregnant Women: A Qualitative Study

Aims & Backgrounds. Reduced physical activity in pregnant women is highly stemmed from their misconceptions and attitudes during pregnancy. This study is aimed at recognizing the facilitators, barriers, and structural factors that influence activity among pregnant women. Participants & Methods. This qualitative study was conducted from January to June 2020 in nulliparous pregnant women. Forty participants selected randomly from the Pounak Health Center of Tehran City, Iran, answered open-ended questions about the obstacles that deprived them of physical activity during pregnancy. Data were analyzed by MAXQDA 12 software. Findings. 620 primary codes, 42 secondary codes, 11 subthemes, and 6 themes were extracted. These themes were divided into the PEN-3 categories: facilitators, barriers, and structural factors. The nurture factors as facilitators had communication and support from others as subthemes. Barriers consisted of sociocultural (participate in pregnancy class with a companion, social beliefs, and culture of poverty), socioeconomic (financial problems), and individual factors (physical, psychoemotional, and spiritual dimensions), and structural factors consisted of environmental (equipment) and organizational (possibilities in health centers) factors. Conclusion. Lack of awareness and misinformation, accessibility obstacles, and economic problems are the worst physical activity barriers during pregnancy. Being among other pregnant women and the physicians' recommendations are the best facilitators of physical activity during pregnancy.

Gamified Challenges in Online Weight-Loss Communities

Gamified challenges, one of the most popular features of online weight-loss communities, enable users to set weight-loss goals and compete with other challenge participants via leaderboards. Using the data from a leading online weight-loss community, we study the effect of gamified challenges on the weight-loss outcome. Our findings indicate that participation in gamified challenges has a positive and significant effect on weight loss. We found that, on average, the participants achieved a weight loss of 0.742 kg by participating in at least one challenge a month. We found that effective challenges do not include a numeric weight goal (e.g., lose 5 kg), focus on exercise-only behavioral goals, and have a large active group size. Further, the results show that the absence (presence) of a numeric weight goal benefits users in exercise (diet) challenges. Moreover, a small active group size can help (hurt) users in exercise (diet) challenges. Our results suggest that gamification elements that induce competition should be used with caution in goal-setting environments, especially when gamifying dietary goals. Online weight-loss communities can recommend a useful combination of numeric weight goals, behavioral goals, and an optimal number of participants in each challenge to induce an encouraging level of social comparison.

The Breast Cancer Weight Loss trial (Alliance A011401): A description and evidence for the lifestyle intervention

The Breast Cancer Weight Loss (BWEL) trial is a randomized controlled trial designed to determine whether weight loss after a breast cancer diagnosis can reduce the risk of cancer recurrence in women with overweight or obesity. The BWEL trial will compare the efficacy of a telephone-based weight-loss intervention plus health education materials versus health education materials alone on invasive disease-free survival in 3,181 women with stage II or III breast cancer and BMI > 27 kg/m² . This report provides a detailed description of the goals and methods of the lifestyle intervention and the evidence supporting the intervention used in the BWEL trial. The intervention's primary goal for participants is to achieve and maintain a weight loss ≥ 10% of baseline weight through increased physical activity and caloric restriction. The evidence supporting the diet, physical activity, and behavioral components of this telephone-based weight-loss intervention, as well as strategies to promote participant engagement and retention, is described. The intervention is provided through 42 sessions delivered by trained health coaches over a 2-year period. If the BWEL lifestyle intervention is successful in improving cancer outcomes, then weight loss will be incorporated into the care of thousands of breast cancer patients.

A Pragmatic Intervention Using Financial Incentives for Pregnancy Weight Management: Feasibility Randomized Controlled Trial

BACKGROUND

Excessive gestational weight gain (GWG) is common and can result in maternal and child health complications. Pragmatic behavioral interventions that can be incorporated into standard obstetric care are needed, and financial incentives are a promising approach.

OBJECTIVE

The aim of this study is to evaluate the feasibility of recruitment, randomization, and retention, as well as treatment engagement and intervention satisfaction, in a behavioral program. The program provided small incentives for meeting behavioral goals of self-weighing and physical activity as well as larger outcome incentives for meeting GWG goals.

METHODS

We recruited 40 adult women in their first trimester of pregnancy from February 2019 to September 2019 at an obstetric clinic. Participants were randomized to 3 intervention components using a 2×2×2 factorial design: daily incentives for self-weighing (lottery vs certain loss), incentives for adhering to the Institute of Medicine's GWG guidelines based on BMI category (monthly vs overall), and incentives for reaching physical activity goals (yes vs no). Participants were asked to complete daily weigh-ins using the Withings Body wireless scale provided by the study, as well as wear a physical activity tracker (Fitbit Flex 2). Feasibility outcomes of recruitment, randomization, and retention, as well as treatment engagement and intervention satisfaction, were assessed. Weight assessments were conducted at baseline, 32-week gestation, and 36-week gestation.

RESULTS

Participants were enrolled at, on average, 9.6 (SD 1.8) weeks' gestation. Of the 39 participants who were oriented to their condition and received the intervention, 24 (62%) were Black or African American, 30 (77%) were not married, and 29 (74%) had an annual household income of less than US $50,000. Of the 39 participants, 35 (90%) completed the follow-up data collection visit. Participants were generally quite positive about the intervention components, with a particular emphasis on the helpfulness of, and the enjoyment of using, the e-scale in both the quantitative and qualitative feedback. Participants who received the loss incentive, on average, had 2.86 times as many days of self-weighing as those who received the lottery incentive. Participants had a relatively low level of activity, with no difference between those who received a physical activity incentive and those who did not.

CONCLUSIONS

A financial incentive-based pragmatic intervention was feasible and acceptable for pregnant women for promoting self-weighing, physical activity, and healthy GWG. Participants were successfully recruited early in their first trimester of pregnancy and retained for follow-up data collection in the third trimester. Participants demonstrated promising engagement in self-weighing, particularly with loss-based incentives, and reported finding the self-weighing especially helpful. This study supports further investigation of pragmatic, clinic-based financial incentive-based interventions for healthy GWG behaviors.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03834194; https://clinicaltrials.gov/ct2/show/NCT03834194.

Rapid Escalation of High-Volume Exercise during Caloric Restriction; Change in Visceral Adipose Tissue and Adipocytokines in Obese Sedentary Breast Cancer Survivors

Simple Summary

Aerobic exercise reduces risk for developing breast cancer or for breast cancer recurrence. In obese women exercise can significantly augment the effects of caloric restriction on visceral fat, reducing metabolic abnormalities and cancer. Women who are older, obese, and sedentary, especially those who have been treated for breast cancer, find it difficult to initiate and achieve the minimum or optimum levels of exercise. In a two-part pilot we found that by providing older, obese, sedentary breast cancer survivors 12 weeks of twice weekly personal training sessions, they could safely increase exercise to ≥200 min/week by 9 weeks during caloric restriction. At 24 weeks, high levels of exercise were still observed with continued behavioral support and study-provided exercise facility. Substantial improvement in visceral fat and breast cancer risk biomarkers were observed with this affordable intervention that is readily exportable to the community.

Abstract

Aerobic exercise reduces risk for breast cancer and recurrence and promotes visceral adipose tissue (VAT) loss in obesity. However, few breast cancer survivors achieve recommended levels of moderate to vigorous physical activity (MVPA) without supervision. In a two-cohort study, feasibility of 12 weeks of partially supervised exercise was started concomitantly with caloric restriction and effects on body composition and systemic risk biomarkers were explored. In total, 22 obese postmenopausal sedentary women (including 18 breast cancer survivors) with median age of 60 and BMI of 37 kg/m² were enrolled. Using personal trainers twice weekly at area YMCAs, MVPA was escalated to ≥200 min/week over 9 weeks. For cohort 2, maintenance of effect was assessed when study provided trainer services were stopped but monitoring, group counseling sessions, and access to the exercise facility were continued. Median post-escalation MVPA was 219 min/week with median 12-week mass and VAT loss of 8 and 19%. MVPA was associated with VAT loss which was associated with improved adiponectin:leptin ratio. In total, 9/11 of cohort-2 women continued the behavioral intervention for another 12 weeks without trainers. High MVPA continued with median 24-week mass and VAT loss of 12 and 29%. This intervention should be further studied in obese sedentary women.

Evaluating the efficacy of mindfulness and acceptance-based treatment components for weight loss: Protocol for a multiphase optimization strategy trial

Behavioral weight loss treatment (BT) for individuals with overweight and obesity is effective but leaves room for improvement. Mindfulness and acceptance-based treatments may bolster weight loss outcomes; yet, little is known about the efficacy of the individual components or the combinations of components that are most effective in producing weight loss above and beyond standard BT strategies for weight loss. This protocol manuscript describes the use of a multiphase optimization strategy to evaluate the independent and combinatory efficacy of three mindfulness and acceptance-based components (mindful awareness, willingness, values). Using a 2 × 2 × 2 factorial design, participants (N = 288) will be randomized to one of eight conditions, each representing a combination of core MABT strategies in addition to foundational BT strategies. Assessments occur at baseline, mid-treatment (week 24 through 26), post-treatment, and at 6, 12, and 24-month follow-up. The primary aim is to elucidate the independent efficacy of each MABT component on weight loss above gold-standard BT. The secondary aims are to evaluate the independent effect of these components on calorie intake, physical activity, and overall quality of life; evaluate target engagement (i.e., the degree to which each treatment component affects proposed mechanisms of action); and evaluate the potential moderating effect of susceptibility to internal and external food cues on outcomes. The exploratory aim is to quantify any component interaction effects (which may be synergistic, fully additive, or partially additive).

Physical activity in the management of obesity in adults: A position statement from Exercise and Sport Science Australia

This Position Statement examines the evidence for physical activity in weight and adiposity loss, prevention of weight and adiposity gain, and in weight regain in adults, and provides guidance on implications for exercise practitioners. Research evidence indicates that >150 min but preferably 300 min per week of aerobic activity of at least moderate intensity is required to prevent weight and adiposity gain, and at least the upper end of this range of activity to prevent weight regain after weight loss. For meaningful weight and total adiposity loss, a minimum of 300-420 min per week of aerobic activity of at least moderate intensity is required. The evidence around the volume of aerobic physical activity required to reduce central adiposity is emerging, and research suggests that it may be substantially less than that required for weight loss. The impact of high-intensity physical activity and resistance exercise for weight management is uncertain. During consultations for weight management, exercise practitioners should advise that metabolic and cardiovascular health benefits can be achieved with physical activity at any weight, and irrespective of weight change.

BestFIT Sequential Multiple Assignment Randomized Trial Results: A SMART Approach to Developing Individualized Weight Loss Treatment Sequences

BACKGROUND

State-of-the-art behavioral weight loss treatment (SBT) can lead to clinically meaningful weight loss, but only 30-60% achieve this goal. Developing adaptive interventions that change based on individual progress could increase the number of people who benefit.

PURPOSE

Conduct a Sequential Multiple Assignment Randomized Trial (SMART) to determine the optimal time to identify SBT suboptimal responders and whether it is better to switch to portion-controlled meals (PCM) or acceptance-based treatment (ABT).

METHOD

The BestFIT trial enrolled 468 adults with obesity who started SBT and were randomized to treatment response assessment at Session 3 (Early TRA) or 7 (Late TRA). Suboptimal responders were re-randomized to PCM or ABT. Responders continued SBT. Primary outcomes were weight change at 6 and 18 months.

RESULTS

PCM participants lost more weight at 6 months (-18.4 lbs, 95% CI -20.5, -16.2) than ABT participants (-15.7 lbs, 95% CI: -18.0, -13.4), but this difference was not statistically significant (-2.7 lbs, 95% CI: -5.8, 0.5, p = .09). PCM and ABT participant 18 month weight loss did not differ. Early and Late TRA participants had similar weight losses (p = .96), however, Early TRA PCM participants lost more weight than Late TRA PCM participants (p = .03).

CONCLUSIONS

Results suggest adaptive intervention sequences that warrant further research (e.g., identify suboptimal responders at Session 3, use PCMs as second-stage treatment). Utilizing the SMART methodology to develop an adaptive weight loss intervention that would outperform gold standard SBT in a randomized controlled trial is an important next step, but may require additional optimization work.

CLINICAL TRIAL INFORMATION

ClinicalTrials.gov identifier; NCT02368002.

Sustaining Regular Exercise During Weight Loss Maintenance: The Role of Consistent Exercise Timing

BACKGROUND

Exercising at a consistent versus variable time of day cross-sectionally relates to greater moderate to vigorous physical activity (MVPA) among weight loss maintainers. This study evaluated the relationships between exercise timing and both MVPA levels and habit strength, as well as stability in exercise timing, over 1 year among maintainers in the National Weight Control Registry.

METHODS

Participants (n = 709) completed questionnaires assessing exercise timing, MVPA, and exercise automaticity (a measure of habit) at baseline and 1-year follow-up. At each assessment, participants were labeled temporally consistent exercisers if >50% of their exercise sessions per week occurred in one time window: early morning, late morning, afternoon, or evening. Participants exercising consistently during the same window at both assessments were labeled as having stable patterns.

RESULTS

Temporally consistent exercise at baseline, regardless of its specific time, related to greater MVPA over time (Ps< .05). Approximately half of temporally consistent exercisers at baseline exhibited stable patterns. Early morning exercise and greater exercise automaticity at baseline predicted stable patterns (Ps< .005). Temporally consistent exercise, especially during the early morning, related to greater automaticity across time (Ps< .01).

CONCLUSIONS

Consistent exercise timing may help maintainers accrue more MVPA. Consistent early morning exercise was most strongly related to exercise automaticity and routine stability.

Exercise training in the management of overweight and obesity in adults: Synthesis of the evidence and recommendations from the European Association for the Study of Obesity Physical Activity Working Group

There is a need for updated practice recommendations on exercise in the management of overweight and obesity in adults. We summarize the evidence provided by a series of seven systematic literature reviews performed by a group of experts from across Europe. The following recommendations with highest strength (Grade A) were derived. For loss in body weight, total fat, visceral fat, intra-hepatic fat, and for improvement in blood pressure, an exercise training program based on aerobic exercise at moderate intensity is preferentially advised. Expected weight loss is however on average not more than 2 to 3 kg. For preservation of lean mass during weight loss, an exercise training program based on resistance training at moderate-to-high intensity is advised. For improvement in insulin sensitivity and for increasing cardiorespiratory fitness, any type of exercise training (aerobic, resistance, and combined aerobic or resistance) or high-intensity interval training (after thorough assessment of cardiovascular risk and under supervision) can be advised. For increasing muscular fitness, an exercise training program based preferentially on resistance training alone or combined with aerobic training is advised. Other recommendations deal with the beneficial effects of exercise training programs on energy intake and appetite control, bariatric surgery outcomes, and quality of life and psychological outcomes in management of overweight and obesity.

Describing the Weight-Reduced State: Physiology, Behavior, and Interventions

Although many persons with obesity can lose weight by lifestyle (diet and physical activity) therapy, successful long-term weight loss is difficult to achieve, and most people who lose weight regain their lost weight over time. The neurohormonal, physiological, and behavioral factors that promote weight recidivism are unclear and complex. The National Institute of Diabetes and Digestive and Kidney Diseases convened a workshop in June 2019, titled "The Physiology of the Weight-Reduced State," to explore the mechanisms and integrative physiology of adaptations in appetite, energy expenditure, and thermogenesis that occur in the weight-reduced state and that may oppose weight-loss maintenance. The proceedings from the first session of this workshop are presented here. Drs. Michael Rosenbaum, Kevin Hall, and Rudolph Leibel discussed the physiological factors that contribute to weight regain; Dr. Michael Lowe discussed the biobehavioral issues involved in weight-loss maintenance; Dr. John Jakicic discussed the influence of physical activity on long-term weight-loss maintenance; and Dr. Louis Aronne discussed the ability of drug therapy to maintain weight loss.

Promotion of physical activity during weight loss maintenance: A randomized controlled trial

OBJECTIVE

Behavioral weight loss (BWL) programs are not sufficiently effective at promoting high levels of moderate-to-vigorous physical activity (MVPA), despite the clear health benefits of exercise and the possibility that high levels of MVPA may improve long-term weight loss. This three-arm randomized controlled trial tested the hypotheses that 1) BWL interventions with an intensive focus on exercise would result in higher amounts of MVPA and greater long-term weight loss, compared to standard BWL, and 2) among interventions with an intensive focus on exercise, outcomes would be superior when skills for exercise promotion were taught from an acceptance-based theoretical framework (which fosters willingness to accept discomfort in the service of valued behaviors), versus a traditional behavioral approach.

METHOD

Three hundred and twenty adults with overweight/obesity received group-based BWL for induction of weight loss (Months 1-6) and were randomized to receive one of three interventions for weight loss maintenance (Months 7-18): continued standard behavioral treatment (BT), behavioral treatment with an emphasis on exercise (BT + PA), or acceptance-based treatment with an emphasis on exercise (ABT + PA).

RESULTS

MVPA and percent weight loss did not significantly differ by condition at 12 or 18 months. Participants engaging in relatively higher levels of MVPA had greater long-term weight losses compared to participants engaging in lower levels of MVPA.

CONCLUSIONS

Further clinical innovations are needed so that participants in BWL programs can more readily adopt and maintain the recommended amounts of MVPA. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

A Randomized Trial Evaluating Exercise for the Prevention of Weight Regain

OBJECTIVE

This study aimed to evaluate the effectiveness of three levels of exercise on weight regain subsequent to clinically meaningful weight loss (WL).

METHODS

Adults with overweight or obesity (n = 298) initiated a 3-month behavioral WL intervention, which included reduced energy intake, increased exercise, and weekly behavioral counseling. Participants achieving ≥5% WL (n = 235) began a 12-month behavioral WL maintenance intervention and were randomized to 150 min/wk (n = 76), 225 min/wk (n = 80), or 300 min/wk (n = 79) of partially supervised moderate-to-vigorous-intensity exercise.

RESULTS

Participants randomized to 150, 225, and 300 minutes of exercise completed 129 ± 30, 153 ± 49 and 179 ± 62 min/wk of exercise (supervised + unsupervised), respectively. Mean WL at 3 months (9.5 ± 3.1 kg) was similar across randomized groups (P = 0.68). Weight change across 12 months was 1.1 ± 6.5 kg, 3.2 ± 5.7 kg, and 2.8 ± 6.9 kg in the 150, 225, and 300 min/wk groups, respectively. Intent-to-treat analysis revealed no significant overall trend across the three treatment groups (P = 0.09), effects for group (P = 0.08), or sex (P = 0.21).

CONCLUSIONS

This study found no evidence for an association between the volume of moderate-to-vigorous-intensity exercise and weight regain across 12 months following clinically relevant WL. Further, results suggest that exercise volumes lower than those currently recommended for WL maintenance, when completed in conjunction with a behavioral weight-maintenance intervention, may minimize weight regain over 12 months.

Factors and Inequality of Underweight and Overweight among Women of Reproductive Age in Myanmar: Evidence from the Demographic Health Survey 2015-2016

(1) Background: This study aims to identify the factors of underweight and overweight/obesity among reproductive age (15-49 years) women in Myanmar, and assess the level of inequity in the double burden of malnutrition. (2) Methods: The study used Myanmar Demographic and Health Survey 2015-2016 data. Multinomial logistic regression models were fitted to identify the factors affecting underweight and overweight/obesity; and concentration indices (CI) were estimated to assess socioeconomic inequalities. (3) Results: A total of 12,643 reproductive age women were included in the analysis. Higher risk of underweight was found in women aged 20-29 years, aged 30-39 years, and 40-49 years compared to women aged 15-19 years; women who were unemployed or had manual occupation relative to those in non-manual employment. Women aged 40-49 years (compared to those who were 15-29 years); had primary education, and secondary education (compared to those who had no education); being married, and widowed/divorced/separated (compared to being never married); belonging to the poor quintile, middle quintile, richer, richest quintile (compared to the poorest quintile); having residence in urban areas (compared to rural areas) and in Kachin, Taninthayi, Yangon province (than those who lived in Naypytiaw province) had a higher risk of being overweight/obese. Socioeconomic inequalities were detected, with overweight/obesity strongly concentrated (CI: 0.19) amongst the higher quintiles and underweight concentrated (CI: -0.060) amongst the poorest. (4) Conclusions: Equity oriented nutrition interventions with a focus on improving the socioeconomic status of poor households may benefit undernourished women, while richer households should be focused to curb the overweight/obesity problem.

Early Physical Activity Adoption Predicts Longer-Term Physical Activity Among Individuals Inactive at Baseline

BACKGROUND

To examine the relationship between early physical activity (PA) adoption (2, 3, and 4 mo) and longer-term PA adherence (1 y) among individuals who were inactive at baseline and received a lifestyle intervention.

METHODS

Participants (n = 637) received weekly behavioral weight loss sessions, calorie reduction, and PA goals (50-175 min/wk progression). PA was assessed via self-reported measures at baseline, months 2 to 4, and 1 year.

RESULTS

PA at months 2 to 4 was significantly correlated with PA at 1 year (rs = .29-.35, P < .01). At all early time points, those failing to meet the prescribed PA goal (early nonadopters) engaged in significantly less PA at 1 year than those meeting the early PA goal (initial adopters). For example, using 2-month criteria, initial adopters engaged in 108.3 minutes per week more at 1 year compared with early nonadopters (P < .01) and had 2.8 times the odds (95% confidence interval, 1.9-4.2) of meeting the 1-year PA goal (≥175 min/wk, P < .01).

CONCLUSIONS

Failure to achieve PA goals at 2, 3, or 4 months results in less overall PA at 1 year. Thus, PA observed as early as month 2 may be a useful indicator for identifying at-risk individuals who may benefit from more intensive PA intervention strategies.

Behavioral Approaches to Weight Management for Health and Wellness

Obesity has become a public health crisis associated with serious health problems. It is a problem that is, by and large, remarkably simple: you gain weight as a result of consuming more calories than you burn. Applied behavior analysis and behavior therapy have produced a range of methods and technologies well-suited to address the problems of overeating and physical inactivity. These methods and technologies, and the conceptual foundations underpinning them, are the focus of this article.

Strategies for Physical Activity Interventions in the Treatment of Obesity

Physical activity contributes to body weight regulation. At least 150 minutes per week of moderate-to-vigorous intensity physical activity may be needed. When not coupled with dietary restriction, physical activity contributes to an average weight loss of approximately 2 to 3 kg in interventions up to 6 months in duration; when added to modest dietary restriction it adds 20% additional weight loss compared with modest dietary restriction alone. Physical activity is associated with enhanced long-term weight loss and attenuation of weight regain and should be included within clinical and public health approaches to prevent weight regain and to treat obesity.

Pathobiology and Reversibility of Prediabetes in a Biracial Cohort (PROP-ABC) Study: design of lifestyle intervention

INTRODUCTION

Intensive lifestyle intervention (ILI) prevents progression from prediabetes to type 2 diabetes (T2D) but reversal of prediabetes is less well studied.

RESEARCH DESIGN AND METHODS

The overall objectives of the Pathobiology and Reversibility of Prediabetes in a Biracial Cohort (PROP-ABC) Study (ClinicalTrials.gov ID: NCT02027571) are to determine the natural history and reversibility of prediabetes. The study tests specific hypotheses on the patterns of progression to prediabetes among normoglycemic African-American (AA) and European-American (EA) offspring of parents with T2D; emergence of microvascular and macrovascular complications during transition from normal to impaired glucose regulation; significance of the 'metabolically healthy' obese phenotype; and effect of duration of the prediabetic state on its reversibility with lifestyle intervention. Participants who developed incident prediabetes were offered ILI and evaluated quarterly for 5 years. The primary outcome was restoration of normal glucose regulation (fasting plasma glucose <100 mg/dL and two-hour plasma glucose (2hrPG)<140 mg/dL).

RESULTS

Of the 223 subjects enrolled in the PROP-ABC Study, 158 participants with incident prediabetes started ILI. The mean age was 53.3±9.28 years; body mass index 30.6±6.70 kg/m²; 70% were female, 52.4% AA and 47.6% EA. The ILI program used goal setting, weight-based calorie restriction, physical activity (180 min/week), self-monitoring, and meal replacement. Monthly face-to-face (F2F) counseling sessions during the initial 6 months, and quarterly visits thereafter, were supplemented with electronic and postal contacts. Attendance at F2F sessions was highly correlated with weight loss (r=0.98, p<0.0001). Meal replacement induced ~5 kg weight loss within 3 months in participants with recrudescent weight pattern. Self-reported exercise minutes correlated with pedometer step counts (r=0.47, p<0.0001).

CONCLUSION

The PROP-ABC Study has demonstrated the feasibility of executing an ILI program designed to test reversibility of incident prediabetes in a biracial cohort.

The Effect of Low-Volume High-Intensity Interval Training on Body Composition and Cardiorespiratory Fitness: A Systematic Review and Meta-Analysis

BACKGROUND

Evidence for the efficacy of low-volume high-intensity interval training (HIIT) for the modulation of body composition is unclear.

OBJECTIVES

We examined the effect of low-volume HIIT versus a non-exercising control and moderate-intensity continuous training (MICT) on body composition and cardiorespiratory fitness in normal weight, overweight and obese adults. We evaluated the impact of low-volume HIIT (HIIT interventions where the total amount of exercise performed during training was ≤ 500 metabolic equivalent minutes per week [MET-min/week]) compared to a non-exercising control and MICT.

METHODS

A database search was conducted in PubMed (MEDLINE), EMBASE, CINAHL, Web of Science, SPORTDiscus and Scopus from the earliest record to June 2019 for studies (randomised controlled trials and non-randomised controlled trials) with exercise training interventions with a minimum 4-week duration. Meta-analyses were conducted for between-group (low-volume HIIT vs. non-exercising control and low-volume HIIT vs. MICT) comparisons for change in total body fat mass (kg), body fat percentage (%), lean body mass (kg) and cardiorespiratory fitness.

RESULTS

From 11,485 relevant records, 47 studies were included. No difference was found between low-volume HIIT and a non-exercising control on total body fat mass (kg) (effect size [ES]: - 0.129, 95% confidence interval [CI] - 0.468 to 0.210; p = 0.455), body fat (%) (ES: - 0.063, 95% CI - 0.383 to 0.257; p = 0.700) and lean body mass (kg) (ES: 0.050, 95% CI - 0.250 to 0.351; p = 0.744), or between low-volume HIIT and MICT on total body fat mass (kg) (ES: - 0.021, 95% CI - 0.272 to 0.231; p = 0.872), body fat (%) (ES: 0.005, 95% CI - 0.294 to 0.304; p = 0.974) and lean body mass (kg) (ES: 0.030, 95% CI - 0.167 to 0.266; p = 0.768). However, low-volume HIIT significantly improved cardiorespiratory fitness compared with a non-exercising control (p < 0.001) and MICT (p = 0.017).

CONCLUSION

These data suggest that low-volume HIIT is inefficient for the modulation of total body fat mass or total body fat percentage in comparison with a non-exercise control and MICT. A novel finding of our meta-analysis was that there appears to be no significant effect of low-volume HIIT on lean body mass when compared with a non-exercising control, and while most studies tended to favour improvement in lean body mass with low-volume HIIT versus MICT, this was not significant. However, despite its lower training volume, low-volume HIIT induces greater improvements in cardiorespiratory fitness than a non-exercising control and MICT in normal weight, overweight and obese adults. Low-volume HIIT, therefore, appears to be a time-efficient treatment for increasing fitness, but not for the improvement of body composition.

Lifestyle modification approaches for the treatment of obesity in adults

The U.S. Preventive Services Task Force has recommended that primary care clinicians screen all adults for obesity and provide those affected intensive multicomponent behavioral interventions. Approximately 95 million U.S. adults qualify for such care, also referred to as lifestyle modification. Using the Guidelines (2013) for Managing Overweight and Obesity in Adults (hereafter, Obesity Guidelines) as a framework, this article reviews the principal components of comprehensive lifestyle modification, which include diet, physical activity, and behavior therapy. To lose weight, the Obesity Guidelines recommend participation for 6 months in high-intensity programs that provide 14 or more counseling sessions with a trained interventionist. When provided face-to-face individual or group treatment, participants lose up to 8 kg (8% of weight) in 6 months and experience improvements in cardiovascular disease risk factors and quality of life. To prevent weight regain, the Obesity Guidelines recommend participation for 1 year in weight-loss-maintenance programs that provide at least monthly counseling. High levels of physical activity, frequent monitoring of body weight, and consumption of a reduced-calorie diet are associated with long-term weight loss. Investigators currently are seeking to increase the availability of lifestyle modification by delivering it in community-based programs, as well as on digital platforms (e.g., Internet and Smartphone). Digitally delivered programs lower costs and expand treatment reach; their efficacy is likely to improve further with the addition of new technologies for monitoring food intake, activity, and weight. Ultimately, to improve long-term weight management, individual lifestyle counseling must be joined with collective and institutional efforts to improve the nation's eating and activity environments. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

The PROMOTE study (High-protein and resistance-training combination in overweight and obesity) for short-term weight loss and long-term weight maintenance for Chinese people: a protocol for a pilot randomized controlled trial

Background

It is very important for clinicians and dieticians to explore reasonable weight management strategies for obese people that address both short-term weight loss and subsequent weight maintenance. We hypothesized that resistance training combined with a high-protein diet would result in similar short-term weight loss but better long-term weight maintenance than either a conventional low-fat diet control or a high-protein diet alone.

Methods/design

This is an 8-week randomized parallel controlled trial followed by a 24-week observational follow-up study. A 48-week supplementary follow-up study will be carried out if necessary. The study will be conducted between June 2019 and October 2020. The 90 overweight or obese participants will be randomly assigned to the conventional low-fat diet group, the high-protein diet group and the high-protein diet and resistance training combination group. Primary outcomes are body weight change at week 8 and week 24 compared with the baseline level.

Discussion

High-quality research on the effect of a high-protein diet combined resistance training on weight loss and weight maintenance is limited in the Chinese population. Our study will provide a basis for obesity management in China and will promote the development of exercise- and diet-related studies.

Trial registration

Chinese Clinical Trial Registry, ChiCTR1900023841. Registered on 14 June 2019.

Eccentric Cycling Training Improves Health-Related Quality of Life in Adolescents with Obesity

INTRODUCTION

While eccentric (ECC) training appears to be more efficient than concentric (CON) training at improving body composition in adolescent with obesity, its impact on health-related quality of life (HRQOL) has never been studied.

OBJECTIVE

The aim of this study is to compare the effects of 2 cycling training modalities, i.e., ECC vs. CON, in adolescents with obesity on HRQOL and health perception (HP).

METHODS

A total of 24 adolescents with obesity, aged 12-16 years, were randomized to either a 12-week ECC or a CON cycling training program performed at the same oxygen consumption (VO2). Anthropometric measurements, body composition, maximal incremental tests, HRQOL (Vécu et Santé Percue de l'Adolescent [VSP-A], Medical Outcome Study Short Form [SF-36]), and HP were assessed at before and after training.

RESULTS AND CONCLUSION

Both CON and ECC cycling trainings promoted significant improvements in BMI, VO2peak, total fat mass, and fat-free mass, with better improvements in body composition parameters in the ECC group (p < 0.05). The VSP-A total score increased after CON (p < 0.01) and ECC (p < 0.001) training, with better enhancement for the ECC group (p < 0.05). The SF-36 physical score increased after both CON (p < 0.01) and ECC (p < 0.001) trainings. The global HP score increased only after ECC training (p < 0.001). Except for the energy-vitality item, no significant correlation was found between changes in HRQOL and its subdomains and anthropometric, body composition, and functional parameters. Both ECC and CON cycling trainings are associated with positive changes in HRQOL and HP. However, ECC seems to induce greater improvements in HRQL and HP than CON cycling training, which is probably not due to the anthropometric, body composition, and functional changes.

Comparative effectiveness of a standard behavioral and physical activity enhanced behavioral weight loss intervention in Black women

Black women typically lose small amounts of weight in behavioral weight loss interventions, partially due to low engagement in physical activity. Culturally relevant enhancement of the physical activity component may improve weight loss. This study compared the effectiveness of a culturally-relevant, physical activity-enhanced behavioral weight loss intervention to a standard behavioral weight loss intervention in Black women (n = 85) over 6 months. The study was conducted in two cohorts from March 2016 to February 2017 at the University of North Carolina at Chapel Hill. Participants had an average age of 48.30 ± 11.02 years with an average body mass index of 36.46 ± 4.50 kg/m². Standard and enhanced groups' weight change (-2.83 kg and -2.08 kg, respectively) and change in physical activity (43.93 min/ week and 15.29 min/week, respectively) did not differ between groups. Significantly more standard group participants lost 5% of baseline weight compared to enhanced group participants. This study produced typical weight loss results in Black women. Behavioral weight loss treatment remains moderately effective for Black women. Strategies to increase attendance and self-monitoring, and the inclusion of cultural contexts to weight-related behaviors are needed to improve outcomes.

An Approach to Obesity Management for Gastroenterologists and Hepatologists

PURPOSE OF REVIEW

Obesity is associated with multiple gastrointestinal and liver diseases such as gastroesophageal reflux disease, Barrett's esophagus, esophageal adenocarcinoma, cholelithiasis, colon polyps, and fatty liver disease. To effectively manage obesity, it is imperative to understand current and emerging therapies and procedures.

FINDINGS

Obesity is becoming increasingly prevalent and is associated with a growing monetary health care burden. Cardiac disease, cerebrovascular disease, and diabetes are among the leading causes of preventable and premature death of Americans related to obesity. In addition to behavioral modification (diet and exercise) and bariatric surgery, multiple pharmacotherapies and endoscopic procedures are newly approved and available for the management of obesity. This paper reviews the current literature on the treatments available for the management of obesity including behavior modification, pharmacotherapy, endoscopic weight loss procedures (endobariatrics), and bariatric surgery.

Physical Activity Intentions and Behavior Mediate Treatment Response in an Acceptance-Based Weight Loss Intervention

BACKGROUND

Acceptance-based treatment (ABT) for weight loss has shown promise for improving outcomes relative to standard behavioral treatment (SBT). One way in which ABT may improve outcomes is through increasing physical activity (PA) intentions and behavior but little research has examined these as mediators of ABT on weight change.

PURPOSE

This study sought to examine ABT's effects on intentions for PA and several objectively measured PA variables during treatment and analyze PA intentions and behaviors as mediators of ABT's effect on weight loss.

METHODS

Participants (N = 189) with overweight/obesity randomized to 1 year of either ABT or SBT completed ecological momentary assessment of PA intentions, accelerometer-based PA assessment, and had weight measured at baseline, mid-treatment, and end of treatment.

RESULTS

ABT had a significantly higher increase than SBT in PA intention minutes at mid-treatment and end of treatment (p < 0.001), and both groups had nonlinear increases in moderate-to-vigorous physical activity (MVPA) that were not significantly different. Sequential mediation models found that ABT's effect on weight loss was partially mediated by higher PA intention minutes at mid-treatment leading to increased MVPA minutes per week. Increased MVPA minutes were obtained by participants increasing the number of days with MVPA bouts.

CONCLUSIONS

ABT's effect on weight loss throughout treatment resulted, in part, from participants increasing their intentions for PA. Controlling for group, higher PA intentions were associated with more PA obtained through more days with exercise.

Mediators of Weight Loss Maintenance in the Keep It Off Trial

Background

An important step toward enhancing the efficacy of weight loss maintenance interventions is identifying the pathways through which successful interventions such as the Keep It Off trial have worked.

Purpose

This study aimed to assess the viability of mediated relationships between the Keep It Off Guided intervention, conceptually and empirically grounded potential mediators, and weight. Repeated measurement of mediators and weight enabled documentation of the temporal ordering of intervention delivery and changes in mediators and in weight among participants randomized to the Guided intervention or Self-Directed comparison group.

Methods

Total, direct, and indirect effects of the Guided intervention on weight change were calculated and tested for significance. Indirect effects were comprised of the influence of the intervention on three change scores for each mediator and the relationship between mediator changes and weight changes 6 months later.

Results

Guided intervention participants regained about 2% less weight over 24 months than Self-Directed participants. Starting daily self-weighing accounted for the largest share of this difference, followed by not stopping self-weighing.

Conclusions

Daily self-weighing mediated 24-month weight loss maintenance.

Trial Registration Number

The trial is registered withClinicalTrials.gov (Identifier: NCT00702455www.clinicaltrials.gov/ct2/show/NCT00702455).

Associations between self-monitoring and weight change in behavioral weight loss interventions

OBJECTIVE

The current study is a secondary analysis of the Live SMART trial, a randomized controlled trial comparing a behavioral weight loss (BWL) condition delivered via smartphone (SMART) to a group-based BWL condition (GROUP) and a control condition (CONTROL). Given the established importance of self-monitoring for weight loss, the aims were to evaluate bidirectional associations between adherence to self-monitoring and weight change and to examine the moderating effect of treatment condition on these associations.

METHOD

Adults with overweight/obesity (n = 276; 83% women; 92.8% White; Mage = 55.1 years; Mbody mass index = 35.2 kg/m2) were instructed to self-monitor dietary intake, daily weight, and physical activity minutes via paper diaries in GROUP and CONTROL and via a smartphone application in SMART. All participants were weighed monthly at the research center. Adherence to self-monitoring was assessed via examination of self-monitoring records.

RESULTS

Generalized linear mixed models revealed that adherence to self-monitoring of dietary intake, self-weighing, and physical activity for each month was associated with weight change throughout that month, such that increased frequency of self-monitoring led to greater weight loss (ps < .001). For the GROUP condition only, poorer weight losses in 1 month were prospectively associated with poor adherence to self-monitoring the following month (ps ≤ .01).

CONCLUSIONS

Results provide evidence of a bidirectional association between self-monitoring and weight change. Better self-monitoring was consistently associated with better weight loss across intervention and tracking modalities. Poorer weight loss was prospectively associated with poorer self-monitoring in group treatment, suggesting that social influences could drive adherence in this form of treatment. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Do we need race-specific resting metabolic rate prediction equations?

Background

Resting metabolic rate (RMR) is a key determinant of daily caloric needs. Respirometry, a form of indirect calorimetry (IC), is considered one of the most accurate methods to measure RMR in clinical and research settings. It is impractical to measure RMR by IC in routine clinical practice; therefore, several formulas are used to predict RMR. In this study, we sought to determine the accuracy of these formulas in determining RMR and assess additional factors that may determine RMR.

Methods

We measured RMR in 114 subjects (67% female, 30% African American [AA]) using IC. Along with standard anthropometrics, dual-energy X-ray absorptiometry was used to obtain fat-free mass(FFM) and total fat mass. Measured RMR (mRMR) by respirometry was compared with predicted RMR (pRMR) generated by Mifflin–St.Joer, Cunningham, and Harris–Benedict (HB) equations. Linear regression models were used to determine factors affecting mRMR.

Results

Mean age, BMI, and mRMR of subjects were 46 ± 16 years (mean ± SD), 35 ± 10 kg/m², and 1658 ± 391 kcal/day, respectively. After adjusting for age, gender, and anthropometrics, the two largest predictors of mRMR were race (p < 0.0001) and FFM (p < 0.0001). For every kg increase in FFM, RMR increased by 28 kcal/day (p < 0.0001). AA race was associated with 144 kcal/day (p < 0.0001) decrease in mRMR. The impact of race on mRMR was mitigated by adding in truncal FFM to the model. When using only clinically measured variables to predict mRMR, we found race, hip circumference, age, gender, and weight to be significant predictors of mRMR (p < 0.005). Mifflin–St.Joer and HB equations that use just age, gender, height, and weight overestimated kcal expenditure in AA by 138 ± 148 and 242 ± 164 (p < 0.0001), respectively.

Conclusion

We found that formulas utilizing height, weight, gender, and age systematically overestimate mRMR and hence predict higher calorie needs among AA. The lower mRMR in AA could be related to truncal fat-free mass representing the activity of metabolically active intraabdominal organs.

Persuasive System Design Principles and Behavior Change Techniques to Stimulate Motivation and Adherence in Electronic Health Interventions to Support Weight Loss Maintenance: Scoping Review

BACKGROUND

Maintaining weight after weight loss is a major health challenge, and eHealth (electronic health) solutions may be a way to meet this challenge. Application of behavior change techniques (BCTs) and persuasive system design (PSD) principles in eHealth development may contribute to the design of technologies that positively influence behavior and motivation to support the sustainable health behavior change needed.

OBJECTIVE

This review aimed to identify BCTs and PSD principles applied in eHealth interventions to support weight loss and weight loss maintenance, as well as techniques and principles applied to stimulate motivation and adherence for long-term weight loss maintenance.

METHODS

A systematic literature search was conducted in PsycINFO, Ovid MEDLINE (including PubMed), EMBASE, Scopus, Web of Science, and AMED, from January 1, 2007 to June 30, 2018. Arksey and O'Malley's scoping review methodology was applied. Publications on eHealth interventions were included if focusing on weight loss or weight loss maintenance, in combination with motivation or adherence and behavior change.

RESULTS

The search identified 317 publications, of which 45 met the inclusion criteria. Of the 45 publications, 11 (24%) focused on weight loss maintenance, and 34 (76%) focused on weight loss. Mobile phones were the most frequently used technology (28/45, 62%). Frequently used wearables were activity trackers (14/45, 31%), as well as other monitoring technologies such as wireless or digital scales (8/45, 18%). All included publications were anchored in behavior change theories. Feedback and monitoring and goals and planning were core behavior change technique clusters applied in the majority of included publications. Social support and associations through prompts and cues to support and maintain new habits were more frequently used in weight loss maintenance than weight loss interventions. In both types of interventions, frequently applied persuasive principles were self-monitoring, goal setting, and feedback. Tailoring, reminders, personalization, and rewards were additional principles frequently applied in weight loss maintenance interventions. Results did not reveal an ideal combination of techniques or principles to stimulate motivation, adherence, and weight loss maintenance. However, the most frequently mentioned individual techniques and principles applied to stimulate motivation were, personalization, simulation, praise, and feedback, whereas associations were frequently mentioned to stimulate adherence. eHealth interventions that found significant effects for weight loss maintenance all applied self-monitoring, feedback, goal setting, and shaping knowledge, combined with a human social support component to support healthy behaviors.

CONCLUSIONS

To our knowledge, this is the first review examining key BCTs and PSD principles applied in weight loss maintenance interventions compared with those of weight loss interventions. This review identified several techniques and principles applied to stimulate motivation and adherence. Future research should aim to examine which eHealth design combinations can be the most effective in support of long-term behavior change and weight loss maintenance.