Exercise and nutrient interactions: Effects on skeletal muscle and body fat mass

The worldwide prevalence of overweight and obesity continues to rise and will soon place unsustainable demands on the healthcare systems of most developed nations. Sarcopenia, the age-related loss of muscle mass, is commonly exacerbated in overweight/obese individuals causing loss of function and independence. Accordingly, a critical goal for overweight/obese adults is to lose fat mass while preserving lean mass to prevent the deleterious effects of inactivity and age-related metabolic diseases. Although numerous studies have manipulated combinations of diet and/or exercise training to promote weight loss, the optimal diet to improve body composition remains controversial. Furthermore, the composition of tissue losses (i.e. fat versus lean mass) is not always examined and individual responses to weight loss interventions have, to date, received little scientific enquiry. Further, the success of a weight loss intervention should be determined not only acutely, but also in terms of its efficacy in maintaining body composition changes. This thesis comprised a series of independent but related studies that investigated the role of exercise and energy-restricted diets of varying macronutrient composition on the maintenance of skeletal muscle mass and body composition...