Scientists have found that calorie restriction a diet comprised of approximately 30 percent fewer calories but with the same nutrients of a standard diet does not extend years of life or reduce age-related deaths in a 23-year study of rhesus monkeys. However, calorie restriction did extend certain aspects of health. The research, conducted by scientists at the National Institute on Aging (NIA) at the National Institutes of Health, is reported in the August 29, 2012 online issue of Nature.