A low-calorie diet, even in people who are not obese, can lead to changes in metabolism and body chemistry that have been linked to better health and longer life, researchers are reporting.

A six-month study published today in The Journal of the American Medical Association found that calorie restriction led to decreases in insulin levels and body temperature. Both are considered signs of longevity, partly because an earlier study by other researchers found both traits in long-lived people. The diet also led to a drop in thyroid hormones and declines in DNA damage.