Effectiveness of the Fun for Wellness Online Behavioral Intervention to Promote Well-Being Actions in Adults With Obesity or Overweight: A Randomized Controlled Trial

Physical activity self-efficacy online intervention for adults with obesity: protocol for a feasibility study

BACKGROUND

Even without weight loss, adults with obesity can greatly benefit from regular physical activity. The Physical Activity Self-efficacy (PAS) intervention is an online behavioral intervention newly developed to promote physical activity in adults with obesity by providing capability-enhancing learning opportunities. The objective of this manuscript is to describe the protocol for a feasibility study designed to investigate the feasibility and acceptability of implementing the PAS online intervention for adults with obesity recruited from a local weight management center in the United States of America (USA).

METHODS

The study design is a prospective, double-blind, parallel-group individual randomized pilot trial. Thirty participants will be randomly assigned to the PAS group or usual care group to achieve a 1:1 group assignment. Recruitment of participants is scheduled to begin on 1 March 2024 at a local weight management center within a private healthcare system in the USA. There are six eligibility criteria for participation in this study (e.g., a body mass index ≥ 25.00 kg/m2). Eligibility verification and data collection will be conducted online. Three waves of data collection will take up to 14 weeks depending on participants' progress in the study. The primary feasibility outcomes in the study will be: (a) participation rate, (b) engagement behavior, and (c) a preliminary effect size estimate for the effect of the PAS intervention on physical activity. Instruments designed to measure demographic information, anthropometric characteristics, self-efficacy, and acceptability will be included in the survey battery. A research-grade accelerometer will be used to measure free-living physical activity objectively. Data will be analyzed using descriptive statistics and inferential statistical models under an intention-to-treat approach.

DISCUSSION

Results are intended to inform the preparation of a future definitive randomized controlled trial.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05935111, registered 7 July 2023.

Mechanisms by Which the Fun for Wellness Intervention May Promote Subjective Well-Being in Adults with Obesity: a Reanalysis Using Baseline Target Moderation

Fun For Wellness (FFW) is a self-efficacy theory-based online behavioral intervention that aims to promote growth in physical activity and well-being. The FFW conceptual model for the promotion of subjective well-being posits that FFW exerts both a positive direct effect, and a positive indirect effect through well-being self-efficacy, on subjective well-being. Subjective well-being is defined in FFW as an individual's satisfaction with their status in seven key domains of their life. Well-being self-efficacy is defined in FFW as the degree to which an individual perceives that they have the capability to attain a positive status in seven key domains of their life. The objective of this study was to use baseline target moderation to assess variation in the impact of FFW on subjective well-being dimensions in adults with obesity. Data (N = 667) from the Well-Being and Physical Activity Study (ClinicalTrials.gov, identifier: NCT03194854) were reanalyzed. There was evidence that well-being self-efficacy at baseline moderated the direct effect of FFW on well-being self-efficacy at 30 days post-baseline for the occupational and psychological dimensions. Both of these findings suggest a "compensatory" effect. Similarly, there was evidence that well-being self-efficacy at baseline moderated the indirect effect of FFW on subjective well-being at 60 days post-baseline through well-being self-efficacy at 30 days post-baseline for the occupational and psychological dimensions. Both of these findings suggest a "compensatory" effect. Finally, there was evidence that well-being self-efficacy at baseline moderated the direct effect of FFW on subjective well-being at 60 days post-baseline for the community, occupational, and physical dimensions. Each of these three findings suggests some version of a "rich-get-richer" effect. In summary, results provide both supportive and unsupportive (i.e., interpersonal, economic, and overall dimensions) evidence regarding variation in the impact of the FFW intervention and should impact the design of future FFW trials.

Measurement of Physical Activity Self-Efficacy in Adults With Obesity: A Latent Variable Approach to Explore Dimensionality, Temporal Invariance, and External Validity

The objective of this study was to improve the measurement of physical activity self-efficacy (PASE) in adults with obesity. To accomplish this objective, a latent variable approach was used to explore dimensionality, temporal invariance, and external validity of responses to a newly developed battery of PASE scales. Data (Nbaseline = 461 and N30 days postbaseline = 427) from the Well-Being and Physical Activity Study (ClinicalTrials.gov, identifier: NCT03194854), which deployed the Fun For Wellness intervention, were analyzed. A two-dimensional factor structure explained responses to each PASE scale at baseline. There was strong evidence for at least partial temporal measurement invariance for this two-dimensional structure in each PASE scale. There was mixed evidence that the effectiveness of the Fun For Wellness intervention exerted a direct effect on latent PASE in adults with obesity at 30 days postbaseline (i.e., external validity) of this two-dimensional structure.