Are High-Protein Diets Really Bad to the Bone?

Nova Southeastern University, Davie, Florida, USA

Objective. The purpose of this investigation was to determine if a high-protein diet affected various parameters of whole body and lumbar bone health in exercise-trained women. Background. It has been posited that consuming a high-protein diet causes calcium to leach from your skeleton; thus promoting demineralization. Methods. Twenty-four women volunteered for this investigation (n=12 control, n=12 high-protein). The control group was instructed to consume their habitual diet; however, the high-protein group was instructed to consume >2.2 grams of protein per kilogram body weight daily (g/kg/d). Body composition was assessed via dual-energy x-ray absorptiometry (DXA). Subjects were instructed to keep a food diary via the mobile app MyFitnessPal®. Results. During the 6-month treatment period, there was a significant difference in protein intake between the control and high-protein groups (control: 1.5±0.3, high-protein: 2.8±1.1 g/kg/d); however, there were no differences in the consumption total calories, carbohydrate or fat. Furthermore, there were no changes in any measure of body composition (i.e., lean body mass, fat mass, bone mineral content, bone mineral density, and body fat %). Conclusion. Despite an 87% higher protein intake (high-protein versus control), 6 months of a high-protein diet had no effect on any measures of bone health or body composition.