Eating Less to Live More Caloric restriction is the practice of
limiting calorie intake without causing malnutrition, with the
goal of improving health and slowing the aging process. It is
the only health intervention consistently shown to improve
length of life in all species studied—until recently, however,
primates, including humans, were rarely studied. Recently
released results of a 20-year, controlled, calorie-restricted
trial in 76 rhesus monkeys have filled in that knowledge gap. A
typical calorie-restricted diet reduces intake by about 30% of
what is calculated to maintain a healthy body weight for an
individual. For example, if a healthy, moderately active adult
requires 2,200 calories to maintain his or her weight, a
calorie-restricted diet would have this person eating about
1,540 calories per day. For this research, the monkeys were
randomly selected for the normal diet group (control) or the
calorie-restricted group. In the restricted group, each monkey’s
diet was individually designed to reduce