Weigh Up The Benefits Of Sleep

Worried about your weight? A good night’s sleep is a great place to start, as recent research reveals some of the mechanisms that lie behind sleep deprivation, appetite and weight-gain

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It should seem straight forward; we sleep — or don’t — and we either feel rested or tired the next day as a result. Yet sleep is needed for a multitude of biological functions and when it comes to weight-gain, it seems to be almost impossible to unpick the one factor that makes all the difference.

If you have ever spent a day feeling exhausted and finding yourself drawn to all the sugary or fatty foods that you might usually avoid (or at least limit) then you are not alone. We don’t need science to tell us that being tired makes us hungry; most of us experience it — new parents in particular! As to why this happens, however, there are various informal theories including an assumption that the body needs more instant energy to keep us awake, or that the motor activity of eating helps to keep us awake. But the effects of sleep-deprivation do not appear to be so simplistic.

The pleasure zone

Have you ever wondered why we don’t crave fruit and vegetables when we’re tired, and are drawn to carbs and fat? One small study from the University of Chicago found that sleep deprivation has an effect on the brain that is similar to the ‘munchies’ caused by smoking cannabis; in that it affects activation of the endocannabinoid (eCB) system, which is important for the brain’s regulation of appetite and energy levels.

Published in the journal Sleep, the study on young, healthy volunteers found that when sleep-deprived, subjects were “unable to resist” snacks such as biscuits, sweets and crisps just two hours after eating a meal — even though the meal had contained 90 per cent of the calories that they would need for the day, and so they should not have been hungry.