Aging is a critical risk factor for the major causes of morbidity and mortality in the western world, including cardiovascular disease, diabetes, cancer, and neurodegenerative disorders. Although the causes of aging are not known, it can be delayed experimentally in rodents by decreasing energy intake in the absence of malnutrition (caloric restriction, CR) and by a growing list of genetic and small molecule interventions. Our work is centered on elucidating the molecular mechanism(s) that mediate these improvements in health and delays in multiple age-related diseases, with a particular focus on nicotinamide adenine dinucleotide (NAD) metabolism and mTOR signaling.