[Chronological nutrition and prevention of lifestyle-related diseases].

Lifestyle controls the circadian rhythms produced by clock genes and affects telomere length that regulates healthspan. Biological clocks are classified into oscillatory (clock genes) and hourglass clocks (telomeres). Clock genes align behavioral and biochemical processes with the day/night cycle. Telomeres, the repeated series of DNA sequences that cap the ends of chromosomes, become shorter during cell division. Shortened telomeres have been documented in various pathological states in lifestyle-related diseases, such as atherosclerosis and diabetes. Human activity is driven by NADH and ATP produced from nutrients, and the resulting NAD and AMP play a predominant role in energy regulation. Caloric restriction and proper exercise increase both AMP and NAD, and extend the healthspan. SIRT1, the NAD-dependent deacetylase, attenuates telomere shortening, while PGC-1alpha, a master modulator of gene expression, is phosphorylated by AMP kinase and deacetylated by SIRT1. Prevention of lifestyle related diseases by chronological nutrition is described based on these mechanisms.