How might a diet plan that is kcalorie restrictive actually help slow the aging process?

Answer 1

In their efforts to understand longevity, researchers have not only observed people but have also manipulated influencing factors, such as diet, in animals. This research has produced some interesting and suggestive findings. For example, animals live longer and have fewer age-related diseases when their energy intakes are restricted. These life-prolonging benefits become evident when the diet provides enough food to prevent malnutrition and an energy intake of about 70 percent of normal; benefits decline as the age at which energy restriction begins is delayed.

Exactly how energy restriction prolongs life remains unexplained, although gene activity appears to play a key role. Energy restriction in animals prevents alterations in gene expression that are associated with aging. Food restriction may also extend the life span by preventing damaging lipid oxidation, thereby delaying the onset of age-related diseases such as cancer and atherosclerosis. Other research suggests that energy restriction beneficially alters several aspects of fat cell metabolism, which may play a role in reducing chronic disease risk and extending life. Experiments with food restriction and longevity in animals have not suggested any direct applications to human nutrition.

Moderate energy restriction (80 to 90 percent of usual intake) in human beings may be valuable. When people restrict energy intake moderately, body weight, body fat, and blood pressure drop, and blood lipids and insulin response improve—favorable changes for preventing chronic diseases. The reduction in oxidative damage that occurs with energy restriction in animals also occurs in people whose diets include antioxidant nutrients and phytochemicals. Diets such as the Mediterranean diet that include an abundance of fruits, vegetables, olive oil, whole grains, and legumes—with their array of antioxidants and phytochemicals—support good health and long life.