Dietary Restriction

Abstract

Dietary restriction (DR), often referred to as calorie restriction (CR), denotes limiting calorie intake by an individual. Since first reported by McClay and Crowell in 1934 that DR increases the life span of rats, interest in the effects of DR on diseases and aging has grown steadily. Studies in last two decades have shown that DR has extensive beneficial effects, including reduced inflammation, reduced cardiovascular problems, improved metabolic fitness, increased stress resistance, and decreased incidence of cancer. DR is also the only known lifestyle intervention that slows the aging process and increases the life span of all the animals tested. Interestingly, DR also provides protection from acute toxicity of certain chemicals. DR or CR implies reduced energy intake, and is responsible for its widespread and evolutionarily conserved benefits. Recent data indicate dietary amino acid restriction can serve as a key mediator of DR benefits, and in mammals, a reduced dietary protein or essential amino acid intake can extend longevity. Several phytochemicals have been vouched for their benefits in this regard; however, their precise role in DR remains unclear.