Caloric Restriction

Calorie restriction, or caloric restriction, or energy restriction, is a dietary regimen that reduces calorie intake without incurring malnutrition or a reduction in essential nutrients. "Reduce" can be defined relative to the subject's previous intake before intentionally restricting calories, or relative to an average person of similar body type.

In a number of species calorie restriction without malnutrition may slow the biological aging process, resulting in longer maintenance of youthful health and an increase in both median and maximum lifespan. However, the life-extending effect of calorie restriction is not shown to be universal. In humans, the long-term health effects of moderate caloric restriction with sufficient nutrients are unknown.

Using rhesus monkeys, a collaboration of the United States National Institute on Aging and the University of Wisconsin found that caloric restriction without malnutrition extended lifespan and delayed the onset of age-related disorders; older age, higher diet quality, and female sex were positive factors affecting the benefits realized from lower caloric intake.