Biomarkers suggest a very low-calorie diet might slow human aging. Compared to a control group, people who ate 25 percent fewer calories than the recommended daily allowance (and people who ate 12.5 percent fewer calories than the RDA while getting 12.5 percent more exercise) developed lower body temperatures and significantly lower insulin levels and DNA damage, which correlate with longevity. This follows previous studies in which 1) a very low-calorie diet apparently slowed heart aging in humans and 2) animals on such diets exceeded their species' maximum life spans.

jama.ama-assn.org/cgi/conte...95/13/1539