Veterans Achieving Weight Loss and Optimizing Resilience-Using Protein

This study examines an evidence-based obesity intervention as a means of reducing the impact of prediabetes on muscle function in obese older men of white and black race. A total of 64 obese (BMI 30 kg/m2) male Veterans aged 55 + yrs, with mild to moderate functional impairments (Short Physical Performance Battery score of 4 to 11 units) and prediabetes, will be randomized to a higher-protein weight loss treatment (HP-WL) or an RDA-level protein control weight loss treatment (C-WL). All participants receive individualized calorie prescriptions calculated to achieve a weight loss of \~1-2 pounds per week and attend weekly group support sessions designed to enhance diet compliance with goal setting, self-monitoring, stress management, and daily diet journaling. They will also attend a weekly low impact, chair exercise class. HP-WL participants are provided a supply of chilled/frozen high-quality protein foods (lean meats, low fat dairy products) sufficient to give 30 g high quality protein for two of three meals daily to help assure diet compliance. C-WL participants are provided 1 serving per day of high quality protein to avoid unintentional bias. Treatment responses will be compared for the primary outcome of functional performance by Short Physical Performance Battery and important secondary measures, including muscle quantity and composition, glucose handling, lean body mass, recent falls and fear of falling, and quality of life at 0, 3 and 6 months. An exploratory aim examines potential mediators of racial differences in treatment responses and documents the most successful intervention strategies. This randomized controlled trial of a balanced, higher-protein diet during a metabolic challenge (caloric restriction) in those with prediabetes also considers racial differences in responses of obese older men to this regimen. Study findings will fulfill the RR\&D mission by advancing interventions to improve physical function in older Veterans, yield novel information about the impact of balanced, higher protein on muscle and glucose handling, and explore racial differences in responses to obesity interventions.