Despite the enormous interest in discovering longevity genes in humans, the results have been elusive, while the effects of physical activity in delaying aging are promising and the importance of caloric restriction is now being systematically investigated. At present, there is enough evidence to define the components of a healthy diet and physical activity lifestyle at the population level and it is clear that lack of exercise is associated with increased risk of premature chronic disease and death. Currently, research aims at defining the type and frequency of genetic variation and its influence on dietary response as well as the impact of diet and exercise on gene expression. The book also provides detailed critical reviews of the relationship between mood changes and the amount of protein, amino acids, carbohydrates and polyunsaturated fatty acids, and the effects of genetic and environmental factors in bone turnover and bone density. This publication will be of great interest to researchers, physicians, exercise physiologists, geneticists, dietitians, food scientists, policy makers in government, private industry and international organizations, and public health workers worldwide.