Evaluating a Remotely Delivered Plant-Based Behavioral Weight Loss Treatment

Many individuals do not achieve clinically significant weight loss following traditional lifestyle modification interventions, potentially because weight loss is dependent upon calorie tracking compliance (to achieve calorie prescriptions), which decreases over time for most. By contrast, non-energy-restricted whole food plant-based diets (WFPBD) have been demonstrated to promote clinically significant weight loss even without calorie prescriptions. The present pilot trial represents the first, to the knowledge of our study team, to empirically test a remotely delivered WFPBD behavioral weight loss intervention for adults with overweight or obesity. Over 12-weeks, participants (N = 21) will follow a non-energy-restricted WFPBD and received nutritional counseling and behavioral weight loss intervention. Participation will occur in two phases (Phase 1: n = 7; Phase 2: n = 14), between which iterative changes to the intervention will be made. Assessments will occur at baseline, mid-treatment, post-treatment, and 3-month follow-up. Data will be analyzed using an intent-to-treat approach. The primary aims of the study will be to assess retention feasibility and acceptability. The secondary aims will be to evaluate the preliminary effectiveness of the intervention on: (1) percent weight loss; (2) dietary intake (i.e., increased intake of low-fat plant-based whole foods and decreased in intake of processed foods and animal products); and (3) waist circumference. The exploratory aims will be to evaluate the preliminary effectiveness of the intervention on physical- and mental health-related quality of life, and to examine potential moderators of treatment success (plant-based diet history, internal disinhibition, social support vs. social sabotage, self-compassion, and psychological flexibility).