Remotely Delivered Behavioral Weight Loss Using an Ad Libitum Plant-Based Diet Versus a Balanced Calorie Deficit Diet

Evaluating a Remotely Delivered Behavioral Weight Loss Intervention Using an Ad Libitum Plant-Based Diet Versus a Balanced Calorie Deficit Diet

This pilot randomized controlled trial will compare a remotely delivered behavioral weight loss program with a balanced calorie deficit diet (the current gold-standard) to a behavioral weight loss program with an ad libitum whole food plant-based diet (WFPBD) amongst adults with overweight/obesity (N = 52). The 6-month intervention will consist of 3 months of moderate-intensity intervention (weekly online modules and brief coaching calls), then a low-intensity period (3 calls over 3-months). Assessments will occur at baseline, 6-weeks, 12-weeks, and post-treatment (6-months). Acceptability, dietary adherence, weight, quality of life, depressive symptoms, and subjective appetite will be assessed.

Inclusion Criteria:

• BMI 27-50 kg/m2
• Ages 18-75 years
• Resides in the U.S.
• Consistent access to internet at home
• Proficient skill level in speaking, writing, and understanding English
• Reporting a desire to lose weight
• Consistently available for 15-minute once-weekly video appointment between the hours of 8 AM and 7 PM EST
• Willing to follow a whole food plant-based diet or a traditional calorie-reduced diet for the study duration
• Individuals must provide consent for the research team to contact their personal physician if necessary, to provide clearance or to consult about rapid weight loss

Exclusion Criteria:

• Currently pregnant or breastfeeding or planned pregnancy within the study period
• Recent weight loss (≥ 5% weight loss in 3-months prior to the study)
• History of bariatric surgery
• Currently following a low-fat plant-based diet
• Medical condition (e.g., cancer, type I diabetes, renal failure), current substance use problem, or psychiatric condition (e.g., active substance abuse, eating disorder) that may pose a risk to the participant during intervention or cause a change in weight
• Recently began or changed the dose of a medication that can cause significant change in weight
• Planning on quitting cigarette smoking over the program period
• Participation in a concurrent weight loss program during the study period
• Medical diagnosis currently influencing weight or appetite
• Medical condition that would limit ability to participate in this program (for example, mild stroke, diabetes if taking insulin, head trauma, cognitive disorder)
• Acute suicidality
• Currently meets criteria for regular loss-of-control eating (i.e., ≥ 9 binge episodes in past 3 months
• Currently reports engaging in a compensatory behavior