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

Perceived importance of moderate-to-vigorous physical activity as a weight control strategy in behavioral weight loss

Background

Previous research has established the importance of moderate-to-vigorous physical activity (MVPA) for weight control. One area of unexplored investigation is the relationship between individuals' perceptions of the importance of MVPA for weight control and MVPA engagement. This study examined the associations between the perceived importance of MVPA and MVPA engagement, weight loss, barriers to PA, and exercise enjoyment in adults enrolled in a long-term behavioral weight loss (BWL) intervention.

Methods

Adults (N = 301) with overweight/obesity (BMI = 27-45 kg/m2) completed an 18-month BWL intervention, followed by a no-intervention 18-month follow-up. At baseline, 6 months, 18 months (i.e., post-treatment), and 36 months (i.e., follow-up), participants ranked the importance of six strategies for weight control: keeping a food record, MVPA, light PA, self-weighing, small portions, and low-calorie diet. Observed MVPA (measured by accelerometer), percent weight loss, perceived barriers to PA, and exercise enjoyment were also measured at each assessment.

Results

Results showed that most participants perceived MVPA as a primary weight control strategy (first, second, or third most important) throughout the intervention, regardless of the weight control goal (weight loss vs. maintenance). Individuals who ranked MVPA as a primary strategy for weight control at concurrent time points, compared to those who did not, engaged in significantly more MVPA at post-treatment, had greater weight loss at follow-up, endorsed fewer barriers to PA at post-treatment and follow-up, and reported greater exercise enjoyment at baseline and post-treatment.

Conclusion

Perceived importance of MVPA was related to subjective experiences of MVPA, MVPA adherence, and weight loss in a long-term BWL intervention.

Understanding the relationship between subclinical depressive symptoms and physical activity in behavioral weight loss treatment

Introduction

Many adults with overweight or obesity experience subclinical symptoms of depression, but little is known about how such symptoms are associated with physical activity (PA) or the experience of PA during behavioral weight loss (BWL) treatment.

Methods

In the current study, adults recruited from the community (N = 320) received 18 months of group-based BWL treatment and wore accelerometers at months 0, 6, and 18 to objectively measure PA. Participants with a mood disorder that was not well controlled were not eligible for the study and were referred for individual treatment. Depressive symptoms, PA barriers, discomfort avoidance, and self-control were self-reported with validated measures.

Results

At baseline, the majority of participants indicated some depressive symptoms, mostly at subclinical levels. Results of multilevel models suggest that depressive symptoms were not significantly associated with concurrent measures of PA engagement (minutes/week) or sedentary behavior (minutes/week) at a given time point (i.e., baseline, 6 months, or 18 months). Results of cross-level interactions suggest that baseline depressive symptoms did not moderate the change in PA or sedentary behavior across time. Concurrent depressive symptoms and PA barriers were significantly and positively associated at a given time point (i.e., baseline, 6 months, or 18 months); however, baseline depressive symptoms did not moderate the improvement in perceived PA barriers across time. At baseline, higher discomfort avoidance and lower self-control each independently and partially mediated the relationship between depressive symptoms and PA barriers.

Conclusion

Results suggest that, among BWL samples in which most participants do not have clinically significant depressive symptoms, the likelihood of adopting and sustaining PA does not depend on the extent of depressive symptoms, but those with elevated symptoms may benefit from approaches that address their perception that engaging in PA is especially challenging.

Exercise for counteracting weight recurrence after bariatric surgery: a systematic review and meta-analysis of randomized controlled trials

Exercise is recommended to prevent post-surgical weight recurrence. Yet, whether exercise interventions are efficacious in this regard has not been systematically evaluated. Moreover, clinicians lack evidence-based information to advise patients on appropriate exercise frequency, intensity, time, and type (FITT) for preventing weight recurrence. Thus, we conducted a meta-analysis of randomized controlled trials (RCTs) involving exercise interventions specifying FITT and weight measurement ≥12 months post-surgery. We reviewed scientific databases up through February 2022 for RCTs comparing exercise interventions reporting FITT and a nonexercise control group on weight ≥12 months post-surgery. Procedures following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses were registered at the international prospective register of systematic reviews (PROSPERO: CRD42022342337). Of 1368 studies reviewed, 5 met inclusion criteria (n = 189; 47.8 ± 4.2 yr, 36.1 6 ± 3.8 kg·m2, 83.2 ± 9.5% female; 61.7% underwent Roux-en-Y gastric bypass). Exercise interventions were largely supervised, lasted 12-26 weeks, and prescribed 80-210 minutes/week of moderate-to-vigorous intensity combined aerobic and resistance exercise over ≤5 days. Within-group effects showed non-statistically significant weight loss for exercise (d = - .15, 95% confidence interval [CI]: -1.96, 1.65; -1.4 kg; P = .87) and weight gain for control (d = .11, 95% CI: -1.70,1.92; +1.0 kg; P = .90), with no difference between these groups (d = -2.26, 95% CI: -2.07, 1.55; -2.4 kg; P = .78). Exercise elicited an additional 2.4 kg weight loss versus control, although this effect was small and statistically non-significant. Ability to draw definitive conclusions regarding efficacy of exercise interventions for counteracting post-surgical weight recurrence was limited by the small number of trials and methodological issues. Findings highlight the need for more rigorous RCTs of exercise interventions specifically designed to reduce post-surgical weight recurrence.

Latent Profile Analysis of Physical Activity Motivation during Behavioral Weight Loss Treatment

Participants in behavioral weight loss (BWL) treatment often struggle to meet and maintain physical activity (PA) prescriptions; improving participants' motivation for the behavior is a potential intervention strategy. Self-Determination Theory (SDT) outlines a continuum of qualitatively different dimensions of motivation, suggesting that more self-determined forms of motivation should predict more PA, whereas less self-determined forms of motivation should be unrelated or negatively related to PA. Although SDT has ample empirical support, most existing research in this area has used statistical analyses that oversimplify the complex, interdependent relationships between dimensions of motivation and behavior. This study's purpose was to explore commonly occurring motivational "profiles" for PA based on the SDT dimensions of motivation (amotivation, external, introjected, integrated/identified, and intrinsic motivation) and how these profiles relate to PA behavior among participants with overweight/obesity (N=281, 79.4% female) at baseline and six months into BWL treatment. Latent profile analysis determined that three motivational profiles fit the data best at both timepoints and the profile characterized by high self-determined (i.e., integrated/identified and intrinsic) motivation and moderate introjected motivation was by far the most common. There were no differences in physical activity behavior across motivational profiles, which contrasts previous literature. Findings suggest that participants who take the initiative to sign up for intensive BWL programs may have sufficiently high PA motivation, which may be a poor predictor of their actual behavior. Future research should examine these relationships later in treatment, when motivation may have more variability, as well as among participants who initiate lower-commitment weight loss programs (e.g., self-help).

Evaluation and Treatment of Obesity and Its Comorbidities: 2022 Update of Clinical Practice Guidelines for Obesity by the Korean Society for the Study of Obesity

The goal of the 8th edition of the Clinical Practice Guidelines for Obesity is to help primary care physician provide safe, effective care to patients with obesity by offering evidence-based recommendations to improve the quality of treatment. The Committee for Clinical Practice Guidelines comprised individuals with multidisciplinary expertise in obesity management. A steering board of seven experts oversaw the entire project. Recommendations were developed as the answers to key questions formulated in patient/problem, intervention, comparison, outcomes (PICO) format. Guidelines underwent multi-level review and cross-checking and received endorsement from relevant scientific societies. This edition of the guidelines includes criteria for diagnosing obesity, abdominal obesity, and metabolic syndrome; evaluation of obesity and its complications; weight loss goals; and treatment options such as diet, exercise, behavioral therapy, pharmacotherapy, and bariatric and metabolic surgery for Korean people with obesity. Compared to the previous edition of the guidelines, the current edition includes five new topics to keep up with the constantly evolving field of obesity: diagnosis of obesity, obesity in women, obesity in patients with mental illness, weight maintenance after weight loss, and the use of information and communication technology-based interventions for obesity treatment. This edition of the guidelines features has improved organization, more clearly linking key questions in PICO format to recommendations and key references. We are confident that these new Clinical Practice Guidelines for Obesity will be a valuable resource for all healthcare professionals as they describe the most current and evidence-based treatment options for obesity in a well-organized format.

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.

Testing the Feasibility and Acceptability of an Acceptance and Commitment Therapy Intervention to Increase Physical Activity among Individuals with Depression: A Protocol Paper

Background

Engaging in regular physical activity (PA) is particularly important among individuals with depression, who are at heightened risk for a host of negative health outcomes. However, people with depression are 50% less likely to meet national guidelines for PA and face unique barriers to PA adherence, including lower distress tolerance and motivation for exercise. Acceptance and Commitment Therapy (ACT) may offer promise for increasing PA among adults with depressive symptoms due to its effects on distress tolerance and motivation. Therefore, we developed ACTivity, an ACT-based intervention designed to promote PA among low-active adults with elevated depressive symptoms. Prior to testing the efficacy of ACTivity in an RCT, an important first step is to conduct a preliminary trial to establish feasibility of study procedures for the ACTivity and comparison intervention programs, as well as to establish the credibility/acceptability of the intervention. The purpose of this paper is to describe the ACTivity intervention and the design of this feasibility trial.

Method/Design

We will conduct a feasibility RCT with two parallel groups and a 1:1 allocation ratio comparing ACTivity to a comparison intervention (relaxation training + PA promotion) among 60 low-active adults with elevated depressive symptoms. All study procedures will be conducted remotely.

Discussion

Results of this feasibility study will inform a subsequent RCT designed to test the efficacy of ACTivity. If shown to be efficacious, ACTivity will provide a treatment that can be widely disseminated to increase PA among adults with depressive symptoms and thereby decrease their risk for chronic disease.

A scoping review of behavior change techniques used to promote physical activity among women in midlife

Women in midlife experience health risks that could be mitigated by regular physical activity and reduced sedentary time, but this population rarely achieves physical activity levels that would protect their health. As a result, many behavioral interventions are designed to promote physical activity in this population, which are purportedly guided by theoretical models of health behavior (change) and activate an associated set of behavior change techniques (BCTs). The efficacy and effectiveness of these interventions appear to be limited, however, raising questions about their design and adaptation for women in midlife. Several aspects of these interventions are currently unclear. Specifically, which women they target (i.e., how “midlife” and “sedentary” or “inactive” are defined), which theoretical models or behavior BCTs are used, and how BCTs are activated in such interventions. A synthesis of this information would be useful as an initial step toward improving physical activity interventions for this at-risk group, and thus, represented the goal of the present scoping review. Eligibility required publication in a peer-reviewed journal in English between 2000 and 2021, inclusion of only women in midlife who did not have any medical or other restrictions on their physical activity (e.g., cancer diagnosis), and free-living physical activity or sedentary behavior as the target outcome (with associated assessment). Of the 4,410 initial results, 51 articles met inclusion criteria, and these described 36 unique interventions. More than half of the articles (59%) named an underlying theoretical model and interventions included an average of 3.76 identifiable BCTs (range 1–11). However, descriptions of many interventions were limited and did not provide enough detail to determine whether or how specific BCTs were activated. Interventions also used a wide range of inclusion criteria for age range and starting activity level, which has implications for targeting/tailoring and effectiveness, and many interventions focused on marginalized populations (e.g., women from racial/ethnic minority backgrounds, those un- or under-insured). The present review identifies some strengths and highlights important limitations of existing literature, as well as key opportunities for advancing the design and potential utility of physical activity interventions for women in midlife.

Subjective experiences of physical activity and forecasting bias during behavioral weight loss

Introduction

Engagement in physical activity (PA) is a critical component of behavioral weight loss (BWL) treatment. Subjective experiences surrounding PA may shape exercise decisions and need to be further understood within a BWL sample.

Methods

Participants in this study were adults with overweight/obesity enrolled in an 18-month BWL program. At baseline, six, and 18 months, participants (N = 320) predicted how they would feel during a lab-based walking task and rated their experiences mid-walk and post-walk. They also completed self-report questionnaires assessing depressive symptoms and discomfort intolerance.

Results and Discussion

Results indicated that exercise experience and expectations were more positive at later treatment points than at baseline. At each assessment point, post-walk ratings were more positive than mid-walk ratings, but pre-walk ratings did not differ from mid-walk ratings, suggesting BWL participants were relatively accurate in predicting their PA experience. These results suggest treatment-seeking adults with overweight/obesity feel most positive upon completion of PA, may not experience a forecasting bias as hypothesized and seem to have increasingly positive PA expectations and experiences as they proceed through treatment and lose weight. Lower discomfort intolerance and depressive symptoms were associated with more positive PA expectations and experiences. Understanding these individual differences in PA experience can inform intervention strategies.

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 relation of grit to weight loss maintenance outcomes

Biological, genetic, and environmental factors make weight loss very difficult. Acceptance-based behavioral treatment (ABT) supplements standard behavioral treatments (BT) for obesity by teaching skills to accept the discomfort inherent to weight control behaviors and prioritize long-term, values-based goals. Grit, the ability to persevere in goal pursuit, overlaps conceptually with ABT principles and may predict outcomes in ABT. During a randomized controlled trial comparing three weight loss interventions (BT, BT with an emphasis on physical activity [BT+PA], ABT with an emphasis on physical activity [ABT+PA]), this study examined if grit predicted weight loss, intervention engagement (session attendance and dietary self-monitoring), and perceived intervention effectiveness, and whether intervention condition moderated these relationships. Participants (N=309) with overweight/obesity enrolled in an 18-month weight loss intervention completed the Short Grit Scale at baseline. Weight and PA were measured at baseline, during the intervention (12 and 18 months), and at follow-up (24 and 36 months). Session attendance and dietary self-monitoring were assessed throughout the intervention, and perceived intervention effectiveness at end-of-intervention. The relation of grit to several outcomes depended on condition. In ABT+PA, but not BT or BT+PA, lower grit related to higher weight loss at 12 and 24 months, session attendance, and perceived intervention effectiveness. Grit was not related to PA or dietary self-monitoring in any condition. ABT's focus on building skills to facilitate long-term goal pursuit may be unique and beneficial to those with lower grit. Those with higher grit may already possess ABT-consistent skills and benefit less from ABT. Research on trait-level characteristics like grit in relation to weight must be cautious not to reinforce weight bias; rather, this work suggests that an evidence-based intervention (ABT) may be well-suited to those with lower grit levels seeking weight loss.

Real-time fluctuations in mindful awareness, willingness, and values clarity, and their associations with craving and dietary lapse among those seeking weight loss

Background

Mindful awareness, willingness and values clarity have been examined as protective factors across a wide range of problems, including overweight/obesity. However, these variables have almost exclusively been examined at the trait-level. It is possible that these variables also fluctuate within individuals in daily life, and that these intraindividual fluctuations may in turn be related to food craving and dietary lapse. The current study used ecological momentary assessment (EMA) to examine the extent to which momentary mindful awareness, willingness, and values clarity varied within-person, and were associated with craving and likelihood of dietary lapse among weight-loss seeking individuals with overweight/obesity prior to starting a weight loss program. We also examined the extent to which craving was associated with dietary lapse.

Methods

Adults with overweight/obesity (N = 126) completed one week of EMA prior to enrolling in a randomized controlled trial of behavioral weight loss treatments. They responded to EMA questions assessing dietary lapses, craving, mindful awareness, willingness, and values clarity six-times per day.

Results

Mindful awareness, willingness, and values clarity demonstrated substantial within-person variability, and higher within-person mindful awareness, willingness, and values clarity were concurrently (but not prospectively) associated with lower craving and likelihood of dietary lapse. Higher craving was concurrently (but not prospectively) associated with higher likelihood of dietary lapse. Between-person, higher mindful awareness, willingness, and values clarity were associated with lower craving and likelihood of dietary lapse, and higher craving was associated with greater frequency of dietary lapses.

Conclusion

Mindful awareness, willingness, and values clarity vary substantially at the daily level, and may be important mechanisms to target to reduce craving and dietary lapses in the daily lives of individuals with overweight/obesity.