Evaluation of a new causal chain model for predicting embedded psychosocial and behavioral relationships in a community-based obesity treatment seeking maintained weight loss

Behavioral and Psychosocial Mediators of the Effects of Increased Self-Regulation on Short- and Long-Term Weight Loss in Women Within Community-Based Obesity Treatments

The aim of this study was to evaluate behavioral mediators of relationships between increased self-regulation of eating and weight loss so that findings on psychosocial correlates of treatment-associated weight change could be extended. Participants were women enrolled in 6-month community-based obesity treatments using primarily self-regulatory (SR-treatment, n = 52) or education-focused (Didactic training, n = 54) methods. Changes from baseline in self-regulation of eating, self-efficacy for controlled eating, emotional eating propensity, exercise, and the diet were first calculated. There were significant overall improvements in each psychosocial and behavioral measure, and weight. Except for emotional eating change from baseline-Month 12, improvements were each significantly greater in the SR-treatment group. Mediation of the relationships of change in self-regulation with 6-, 12-, and 24-month weight changes, by changes in self-efficacy and emotional eating, were significant, R2s = .19-.26, ps < .001. Only changes in emotional eating over 6 and 12 months were significant mediators. Mediations of the same self-regulation-weight change relationships by changes in exercise and the diet were also significant, R2s = .19-.28, ps < .001, and only changes in exercise over 12 and 24 months were significant mediators. Although group membership did not moderate effects on weight, substitution of sweets for the (composite) diet demonstrated it to be a significant mediator over 6 and 12 months. In women with obesity, self-regulation improvement was associated with short- and longer-term weight loss through changes in emotional eating, exercise, and sweets consumption. Thus, behavioral treatments will benefit from targeting those variables.

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

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

The Role of Change in Self-efficacy in Maintaining Exercise-Associated Improvements in Mood Beyond the Initial 6 Months of Expected Weight Loss in Women with Obesity

BACKGROUND

Although mechanisms are unclear, there is a robust association between exercise and mood improvements. However, beyond ~ 6 months of expected weight loss, weight-management behaviors such as exercise wane as weight gradually regains in most adults. The amount of exercise required to maintain mood improvement is unknown, as is the possible role of theory-based psychosocial changes associated with treatment such as in self-efficacy.

METHODS

Women who volunteered for a community-based cognitive-behavioral obesity treatment emphasizing exercise and building self-efficacy via self-regulating through lifestyle challenges/barriers, and were of the 86% who reduced their negative mood during its initial 6 months, were allocated into groups who either maintained their negative mood reduction (Sustain group, n = 43) or reverted toward initial levels of negative mood (Revert group, n = 73) during months 6-24. A binary stepwise logistic regression analysis assessed whether exercise amount and/or change in self-efficacy significantly classified Sustain vs. Revert group membership.

RESULTS

Change in exercise amount was not significantly associated with group membership. However, after additional entry of change in exercise self-efficacy, a significant association was found - successfully classifying 70% and 42% of the Revert and Sustain group participants, respectively. When self-efficacy change was entered as the sole independent variable, group membership was classified with 62% accuracy, overall (96% in the Revert group).

CONCLUSIONS

Consistent with behavioral explanations of the exercise-mood change relationship, it was interpreted that self-efficacy, rather than exercise amount, was an important correlate of mood change beyond month 6. Suggestions for bolstering self-efficacy later in behavioral obesity treatments were provided.

Theory to treatment to theory: Evolving a community-based obesity intervention

Within weight-loss treatments, a better understanding of psychosocial correlates of exercise and controlled eating is required to improve lagging outcomes. Within this two-phase study, women with obesity participating in community-based treatments with educational (Phase 1 n = 57, Phase 2 n = 44) and behavioral (Phase 1 n = 80, Phase 2 n = 53) formats were contrasted on psychosocial variables over 3 and 6 months and their interrelations based on the mood-behavior-model and coaction theory. Phase 1 findings informed curricular extensions in Phase 2. In Phase 1, there were significant overall improvements in total mood disturbance, self-regulation of exercise, self-regulation of eating, and weight, which were more pronounced in the behavioral vs. educational format group (-3.5 % vs. -1.4 % weight loss, respectively). Mediation analyses indicated that change in self-regulation of exercise mediated the prediction of change in self-regulation of eating by mood change. Phase 2 findings were similar; however, effect sizes were greater (-6.2 % vs. -2.9 % weight loss, respectively). Within both phases, increased self-regulation of eating significantly predicted weight reduction. Paths from changes in mood→self-regulation of exercise→self-regulation of eating suggested future program attention focus on treatment-associated mood change reinforcing self-regulation, and self-regulation generalizing from an exercise to eating context. Methods of progressing treatment curricula via theory-testing were suggested.

A 2.5-Year Weight Management Program Using Noom Health: Protocol for a Randomized Controlled Trial

BACKGROUND

Overweight and obesity are serious public health concerns. As the prevalence of excess weight among individuals continues to increase, there is a parallel need for inexpensive, highly accessible, and evidence-based weight loss programs.

OBJECTIVE

This weight loss trial will aim to examine the efficacy of the Noom weight loss program in comparison to a digital control after a 6-month intervention phase and a 24-month maintenance phase, with assessments continuing for 2 years beyond the intervention (to 30 months-after the baseline). The secondary outcomes include quality of life, psychosocial functioning, sleep quality, physical activity, diet, and health status. This trial will also examine the severity of obesity-related functional impairment, weight loss history, and demographic moderators, along with adherence and self-efficacy as mediators of the outcome.

METHODS

A total of 600 participants were randomized in a parallel-group, controlled trial to either Noom Healthy Weight Program (intervention) or Noom Healthy Weight Control (control) for a 6-month intervention. Both intervention and control groups include diet and exercise recommendations, educational content, daily logging capabilities, and daily weigh-in entries. The Noom Healthy Weight Program also includes a coach support for weight loss. Remote follow-up assessments of eating, physical activity, psychosocial factors, app use data, and weight will be conducted at 1, 4, 6, 12, 18, 24, and 30 months after baseline. Weight is measured at each follow-up point during a Zoom call using the participants' scales.

RESULTS

Enrollment began in March 2021 and the 6-month intervention phase ended in March 2022. Data collection for the final assessment will be completed in March 2024.

CONCLUSIONS

This study tests commercially available digital lifestyle interventions for individuals with overweight and obesity seeking weight loss support. Data obtained from the study will evaluate whether the Noom Healthy Weight Control Program can help individuals overcome weight loss, achieve long-term maintenance, adhere to lifestyle changes, and feature use barriers that are present in other traditional weight loss treatments.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04797169; https://clinicaltrials.gov/ct2/show/NCT04797169.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/37541.

Weight Maintenance after Dietary Weight Loss: Systematic Review and Meta-Analysis on the Effectiveness of Behavioural Intensive Intervention

After a low-calorie diet, only 25% of patients succeed in maintaining the result of weight loss for a long time. This systematic review and meta-analysis aims to explore whether patients undergoing intensive intervention during the maintenance phase have a greater preservation of the weight achieved during the previous slimming phase than controls. A bibliographic search was conducted using PubMed, Scopus, and Cochrane databases for clinical trials and randomised, controlled trials investigating the role of choice in weight-loss-maintenance strategies. Only studies with a follow-up of at least 12 months were considered. A total of eight studies, for a total of 1454 patients, was identified, each comparing a group that followed a more intensive protocol to a control group. Our metanalysis highlighted that an intensive approach even in the maintenance phase could be important to ensure greater success in the phase following the weight-loss period. However, it should be pointed out that the improvement was not so different from the trend of the respective controls, with a non-statistically significant mean difference of the effect size (0.087; 95% CI −0.016 to 0.190 p = 0.098). This finding, along with the observation of a weight regain in half of the selected studies, suggests this is a long work that has to be started within the weight-loss phase and reinforced during the maintenance phase. The problem of weight control in patients with obesity should be understood as a process of education to a healthy lifestyle and a balanced diet to be integrated in the context of a multidisciplinary approach.