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Delaying meal times could limit impact of jet lag and shift work

Altering meal times could curb health problems caused by disturbed circadian rhythms.

Altering mealtimes could offer a drug-free solution to dealing with the impact of jet lag and shift work, a study suggests.

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Researchers from the University of Surrey examined the impact of delaying mealtimes on the circadian rhythms of ten volunteers. Circadian rhythms are 24-hour changes governed by the body’s internal clocks and determine many physiological processes.

Volunteers were provided with breakfast, lunch and dinner. In the first phase of the study, the first meal was provided 30 minutes after waking, with later meals at subsequent five-hour intervals. In the second phase, each meal was delayed by five hours.

Immediately after each phase, blood samples and fat biopsies were taken to allow measurement of internal circadian rhythms.


Postponing mealtimes by five hours delayed rhythms of blood sugar by the same time frame. This discovery demonstrates that mealtimes synchronise internal clocks that control rhythms of blood-sugar concentration.

Lead investigator of the study Jonathan Johnston said: ‘Regular jet lag and shift work have adverse effects on the body, including metabolic disturbances. Altering mealtimes can reset the body clocks regulating sugar metabolism in a drug-free way.

‘This will help us design feeding regimes to reduce the risk of developing health problems such as obesity and cardiovascular disease in people with disturbed circadian rhythms.’

Wehrens SMT et al (2017) Meal timing regulates the human circadian system. Current Biology. doi: 10.1016/j.cub.2017.04.059




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