Dietary restriction in aging and longevity.

Different types of dietary restriction (DR) have been practiced by humans for religious and medical purposes for millennia, but only during the past three decades has the scientific study of DR at cellular and molecular levels proliferated. Here we review the evidence testing a variety of DR paradigms in the context of aging, focusing on mammalian findings. We discuss potential DR mimetics that modulate autophagy, FGF21, AMPK, mTORC1, NAD+ metabolism, SIRTs, GLP-1R and other pathways as well as organismal and cellular adaptations to DR, including the roles of fasting, hunger, changes in body temperature and fat loss. We also consider the potential negative effects of DR such as increased vulnerability to infections and impaired wound healing. Further, we discuss preclinical evidence evaluating the potential of DR to improve healthspan and treat, prevent or delay age-related diseases including cancer, cardiovascular diseases and neurodegeneration. Finally, we consider the future opportunities for translation, and the challenges inherent to this complex research field.