Military personnel face many physiological challenges, including sustained physical activity and prolonged periods of negative energy balance. Chronic energy deficiency often results in a loss of skeletal muscle mass and can reduce overall bone health. Recent evidence suggests that dietary interventions that provide protein in excess of the current national dietary recommendation may confer protection against the negative effects of energy deficiency on the musculoskeletal system. The primary objective of this randomized, controlled study is to assess the effects dietary protein intake spanning the current acceptable macronutrient distribution range on musculoskeletal health following prolonged energy deficiency. Findings from this investigation will improve current understanding of dietary conditions necessary to reduce the damaging effects of caloric deficiency on musculoskeletal health in warfighters. Furthermore, given the rise in obesity in military populations, findings may aid in the development of nutritional weight management strategies that promote healthy weight loss without compromising musculoskeletal health.

Inclusion Criteria:

• Weight stable with body mass index 22-29 kg/m2
• Physically active
• Refrain from NSAIDS and other aspirin containing medications
• Refrain from alcohol and nicotine

Exclusion Criteria:

• Metabolic or cardiovascular abnormalities, gastrointestinal disorders
• Disease or medication that affects metabolism and/or exercise
• Allergies or intolerance to foods, vegetarian practices, or medications to be used in the study
• Anemia and Sickle Cell Anemia/Trait; abnormal PT/PTT test or problems with blood clotting
• Present condition of alcoholism, use of nutritional/sports supplements, anabolic steroids, or other substance abuse issues
• Musculoskeletal injuries that compromise the ability to exercise
• Blood donation within 8 weeks of beginning the study
• Pregnancy and women not on contraceptives