Eating to improve body composition

For optimal health and athletic performance, gaining lean skeletal muscle mass and losing body fat mass is one ideal outcome of a nutritional/exercise intervention desired by athletes and fitness competitors alike. While achieving a lean muscular physique based on proper diet and intense training may be a goal of bodybuilding and fitness populations, it may not be the primary goal of competitive athletes. Athletes training and competing for specific events are often judged on sport-specific performance affected by a number of interactive variables including but not limited to excellent body composition (i.e. high degree of muscularity and low body fat levels). With these elements in mind, this chapter focuses on various clinical trials that have examined body composition changes through various diet and/or exercise interventions. Issues surrounding the mechanisms governing why substituting carbohydrate for protein and/or fat can enhance body composition are also discussed.