BackgroundObesity remains a leading serious chronic disease and cause of death in the U.S. Despite previous research in diets (i.e., caloric restriction), physical activity levels, and biochemical markers, no studies to date have investigated the combination of an obesity medicine physician with a health coach alongside a commercial program for reducing body weight. As a result, this pilot study aims to assess the relationship between a commercial diet program and health and wellness coaching (HWC) for weight reduction outcomes when delivered in conjunction with an obesity medicine physician chronic disease care model, as a proof-of-concept study. MethodsThis 24-week proof-of-concept study was pragmatic, being an unblinded, unrandomized, uncontrolled, longitudinal, observational study. Its purpose was to assess participant weight reduction from a commercial weight reduction program using a pre-packaged portion-controlled reduced-calorie diet while meeting with a health coach and obesity medicine physician for counseling and support. Participants in the sample underwent a commercial weight reduction program through dietary control while meeting with an HWC. A repeated measures ANOVA was conducted to determine the weight reduction trends across a 24-week program. ResultsThis study included n=53 participants; a majority were white females (n=45; 85%), with an average (SD) age of 50.3 (12.2) years. There was a significant improvement in weight reduction (21.8±9.4 lbs. WL) seen throughout the 24-week program (F (7, 364) = 33.129, p<.001), with a large effect (η2 = 0.922). ConclusionThis proof-of-concept project found that Obesity Medicine Physician-directed, portion-controlled meals and HWC can improve weight reduction across a 24-week program using portioned-controlled meals. Confirmation of these findings and their clinical significance requires a follow-up randomized, controlled clinical trial using validated assessment tools.