High protein (soy/whey) and calcium intake to be examined for weight maintenance and blood lipid effects in obese individuals

Maintaining weight loss is a significant challenge for individuals with obesity, often leading to weight regain after initial success. Current strategies frequently fall short in providing sustainable long-term outcomes. Dietary protein intake is hypothesized to play a crucial role in appetite regulation, satiety, and diet-induced thermogenesis (DIT), potentially aiding in weight maintenance and preserving lean body mass. Additionally, calcium's influence on body weight and blood lipid profiles warrants further investigation, as it may offer an adjunctive benefit in metabolic health.

This parallel randomized controlled trial (RCT) will enroll 200 overweight/obese subjects into an 8-week very low calorie diet (VLCD) weight loss period, followed by a 24-week weight maintenance period. Participants will be randomized to daily supplementation with placebo (maltodextrin), soy protein, whey protein, or calcium-enriched whey protein. Body weight and composition will be measured at baseline (week 0), post-VLCD (week 8), and post-maintenance (week 24). Blood samples will be collected at these time points for lipid profiling. Meal tests will be performed at week 0 and week 24 to assess appetite regulation and DIT. Dietary counseling will be provided regularly.