FIG. 1.

Interactive regulation of food intake and metabolic function by circadian clock genes. Central and peripheral clocks interact with each other to regulate food intake and specific metabolic pathways in key organ systems (1,2,9). Disruption of central or peripheral circadian rhythms can cause an increase in food intake and obesity, which in turn can affect central and peripheral circadian rhythm activity and directly impair metabolic function. Individual organs have their own clocks that directly affect metabolic pathways. The study by Shostak et al. (17) in this issue of Diabetes has identified a new function of clock genes in the regulation of lipolytic activity in white adipose tissue.