title: Nutrition and the circadian system.
abstract: The human circadian system anticipates and adapts to daily environmental changes to optimise behaviour according to time of day and temporally partitions incompatible physiological processes. At the helm of this system is a master clock in the suprachiasmatic nuclei (SCN) of the anterior hypothalamus. The SCN are primarily synchronised to the 24-h day by the light/dark cycle; however, feeding/fasting cycles are the primary time cues for clocks in peripheral tissues. Aligning feeding/fasting cycles with clock-regulated metabolic changes optimises metabolism, and studies of other animals suggest that feeding at inappropriate times disrupts circadian system organisation, and thereby contributes to adverse metabolic consequences and chronic disease development. 'High-fat diets' (HFD) produce particularly deleterious effects on circadian system organisation in rodents by blunting feeding/fasting cycles. Time-of-day-restricted feeding, where food availability is restricted to a period of several hours, offsets many adverse consequences of HFD in these animals; however, further evidence is required to assess whether the same is true in humans. Several nutritional compounds have robust effects on the circadian system. Caffeine, for example, can speed synchronisation to new time zones after jetlag. An appreciation of the circadian system has many implications for nutritional science and may ultimately help reduce the burden of chronic diseases.
authors.affiliation: 1LIGHT Laboratories,Division of Epidemiology and Biostatistics,University of Leeds,LeedsLS2 9JT,UK.
authors.forename: Gregory D M
authors.identifier: http://orcid.org/0000-0003-1995-7040
authors.initials: GD
authors.lastname: Potter
authors.affiliation: 2Nutritional Epidemiology Group,School of Food Science and Nutrition,University of Leeds,LeedsLS2 9JT,UK.
authors.forename: Janet E
authors.initials: JE
authors.lastname: Cade
authors.affiliation: 3LIGHT Laboratories,Division of Cardiovascular & Diabetes Research,University of Leeds,LeedsLS2 9JT,UK.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Grant
authors.affiliation: 1LIGHT Laboratories,Division of Epidemiology and Biostatistics,University of Leeds,LeedsLS2 9JT,UK.
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Hardie
mesh_terms: D000818:Animals; D057906:Circadian Clocks / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D059305:Diet, High-Fat / Q000009:adverse effects; D005247:Feeding Behavior; D006801:Humans; D009747:Nutritional Physiological Phenomena; D009752:Nutritional Status / Q000502:physiology*; D009765:Obesity / Q000209:etiology* / Q000503:physiopathology
keywords: CLOCK circadian locomotor output cycles kaput; Chrononutrition; FAA food anticipatory activity; HFD high-fat diet; Metabolism; Obesity; SCN suprachiasmatic nuclei; SIRT SIRTUIN; TRF time-of-day-restricted feeding; Time-restricted feeding