Circadian rhythms, eating patterns, and sleep: A focus on obesity

In mammals, the biological clock is driven by circadian rhythms, a particular type of biological rhythm that last about 24 hours. There is a close relationship between the functioning of the circadian system, eating and metabolic regulation, which is currently an area of intense research. Alteration of circadian rhythmicity from genetic, behavioral or dietary modifications, leads to behavioral and metabolic disorders, and excessive weight gain. Factors that contribute to circadian disruption include, among others, jet lag, shift work, mistimed and restricted sleep, and irregular eating patterns. This review summarizes the evidence regarding the influence of circadian rhythms on eating processes and the metabolic consequences of circadian disruption. Special focus is on the consequences of disruption of regular eatingfasting and sleep-wake rhythms, and relationships with excessive weight gain, obesity and obesity-related metabolic disorders that are highly prevalent in westernized societies.