Two Years on a High-Protein Diet: Much Ado About Nothing

Nova Southeastern University, Davie, Florida, USA

Objective. The purpose of these case reports was to do a follow-up investigation of five subjects on a high-protein diet over another 1-year period. Background: The long-term effects of a high-protein diet are not well established particularly in well-trained athletes. Methods. Five healthy resistance-trained men (mean ± SD; age 30 ± 5 yr; height 177.9 ± 5.5 cm) volunteered to continue to consume a high-protein diet (>2.2 g/kg/d over another 12-month period). Subjects came to the lab every 6 months to assess body composition. Subjects continued to provide dietary self-reports via the MyFitnessPal mobile app (>150 diet recalls per year). No other instructions were given. Each subject was provided with protein powder so they could attain their protein intake goals. A basic metabolic panel was assessed in a fasted state. Results. Two years on a high-protein diet have no harmful effects. Conclusion. Consuming a high-protein diet for 2 years in resistance-trained men has no deleterious effects on liver or kidney function. Subjects also demonstrated above average bone mineral density.