Is it possible to live a good deal longer by eating a good deal less? Proponents of a strict dietary regimen called calorie restriction (CR) claim that it can extend your life and prevent diseases associated with aging. The diet consists of eating a very low-calorie but nutritionally balanced diet that meets 100% of vitamin, mineral, protein and essential fat needs. But can such a lifestyle, which means a dramatic change in eating habits for most Americans, be the "fountain of youth" its followers claim?
CR gained momentum in the 1930s after studies on mice showed that reducing their normal food intake by about 40% increased their maximum life span by 30% to 40%. Since then, research on worms and monkeys has shown that CR works in other species.
In humans, CR has been shown to improve markers of cardiovascular aging. According to a recent study in the Journal of the American Medical Association, calorie restriction reduces certain markers of aging and disease. The subjects who participated in the six-month study were all overweight. They cut their daily calories by 25% either through diet alone or through diet and exercise. Biomarkers associated with longevity—core body temperature and fasting insulin levels decreased. —were decreased in overweight subjects, but not in other groups. These findings suggest that calorie restriction may help prolong life by preventing diseases and aging in overweight people. Whether people who have normal body weight can show similar improvements has not been proven.
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