Action of food restriction in delaying the aging process.

Food restriction has long been known to prolong life in rodents, and recent studies have shown it to have antiaging effects in regard to a variety of physiologic and pathologic processes. It has been suggested that these actions of food restriction relate to the reduction of metabolic rate per unit of body mass brought about by this dietary regimen. Data are presented in this report showing that food restriction can have a marked life-prolonging action in rats without reducing caloric intake per gram of body weight. Moreover, the food-restricted rats consumed a greater number of calories per gram of body weight during their lifetimes than did the rats fed ad lib, yet they lived longer. Thus, the data in this report do not support the concept that food restriction slows the rate of aging by decreasing the metabolic rate.