Circadian Changes in Gut Peptide Levels and Obesity

Disruptions in biological rhythms that conflict with the normal light-dark cycle, such as occurs in jet lag, shift work, or altered meal timing, have a significant effect on energy homeostasis and often lead to obesity. A significant contributing factor to circadian-induced alterations in energy homeostasis is due to changes in the levels or rhythms of gut peptides. Gut peptides are produced in and secreted from specialized endocrine cells of the gastrointestinal tract and pancreas and coordinate digestion, absorption, and the metabolism of nutrients across the tissues of the body. Changes in the patterns of sleep or mealtimes can alter the release and action of these hormones and lead to increased food intake and aberrant nutrient processing and thus, perpetuate negative metabolic consequences. In this review, we discuss the biological clock, rhythmic phenomenon of gut peptide secretion, possible mechanisms of circadian regulation of gut peptides, and the negative health effects of abnormal rhythms as it relates to obesity.