Physical activity and nutrient intake are important determinants of health throughout life. Many of the alterations in physiological structure and function that occur with age may result from disuse and disability as well as from diets deficient in energy, protein or other specific nutrients. Although a healthy diet can provide significant health benefits, diet alone, is not sufficient to provide optimal health, nor protect us from the hazards of sedentary habits. Nor is physical activity alone. The ideal combines sufficient exercise and a healthy diet.