Improved Function With Enhanced Protein Intake per Meal: A Pilot Study of Weight Reduction in Frail, Obese Older Adults

BACKGROUND: Obesity is a significant cause of functional limitations in older adults; yet, concerns that weight reduction could diminish muscle along with fat mass have impeded progress toward an intervention. Meal-based enhancement of protein intake could protect function and/or lean mass but has not been studied during geriatric obesity reduction. METHODS: In this 6-month randomized controlled trial, 67 obese (body mass index ≥30kg/m(2)) older (≥60 years) adults with a Short Physical Performance Battery score of 4–10 were randomly assigned to a traditional (Control) weight loss regimen or one with higher protein intake (>30g) at each meal (Protein). All participants were prescribed a hypo-caloric diet, and weighed and provided dietary guidance weekly. Physical function (Short Physical Performance Battery) and lean mass (BOD POD), along with secondary measures, were assessed at 0, 3, and 6 months. RESULTS: At the 6-month endpoint, there was significant (p < .001) weight loss in both the Control (−7.5±6.2kg) and Protein (−8.7±7.4kg) groups. Both groups also improved function but the increase in the Protein (+2.4±1.7 units; p < .001) was greater than in the Control (+0.9±1.7 units; p < .01) group (p = .02). CONCLUSION: Obese, functionally limited older adults undergoing a 6-month weight loss intervention with a meal-based enhancement of protein quantity and quality lost similar amounts of weight but had greater functional improvements relative to the Control group. If confirmed, this dietary approach could have important implications for improving the functional status of this vulnerable population (ClinicalTrials.gov identifier: NCT01715753).