People who do not get enough sleep at night are more likely to overeat during the day, scientists have found.
British researchers discovered sleep deprivation can be linked to taking on an extra 385 calories a day – enough to pile on the pounds – as people ate more fatty food and protein.
Even though they spent more time awake, they did no more physical activity than people who had a full night’s sleep and so did not burn up any more calories.
The researchers, from King’s College London, suspect that getting too little sleep affects the body’s hormones, meaning people need to eat more to feel full. The team, whose work has just been published in the European Journal Of Clinical Nutrition, found that sleep-deprived people – those who get less than five and a half hours a night – consumed an average of 385 calories per day more than those who had more than seven hours.
That is equivalent to eating an extra four and a half slices of bread.
King’s College London researcher Dr Gerda Pot said: ‘If long-term sleep deprivation continues to result in an increased calorie intake of this magnitude, it may contribute to weight gain. The main cause of obesity is an imbalance between calorie intake and expenditure, and this study adds to accumulating evidence that sleep deprivation could contribute to this imbalance.’
Getting a full night’s sleep can help you stay slim, the study by scientists at King’s College London found
She added: ‘Reduced sleep is one of the most common and potentially modifiable health risks in today’s society in which chronic sleep loss is becoming more common.’
The research team suspect sleep was tied to calorie intake by the circadian rhythm or body clock, which synchronises bodily functions to the 24-hour pattern of the Earth’s rotation and the way the eye perceives light and dark. It also has a strong influence on our metabolism, including the way we feel hunger and when we feel full.
Experts think disturbing the body clock affects the way key hormones such as leptin, which tells us when we are full, and ghrelin, the ‘hunger’ hormone, are regulated.
Experts think disturbing the body clock affects the way key hormones such as leptin, which tells us when we are full, and ghrelin, the ‘hunger’ hormone, are regulated
A previous study of 26 sleep-deprived adults found that the part of the brain associated with reward went into overdrive when they were exposed to food.
Haya Al Khatib, who led the latest research, said: ‘Our results highlight sleep as a potential third factor, in addition to diet and exercise, to target weight gain more effectively. We are currently conducting a trial in habitually short sleepers to explore the effects of sleep extension on weight gain.’
A large study published in 2014 suggested people in the UK get two hours less sleep a night than they did 60 years ago. The authors of that study, from Oxford, Cambridge, Harvard, Manchester and Surrey universities, warned against ignoring the importance of sleep.
Russell Foster, professor of circadian neuroscience at the University of Oxford, said at the time: ‘We are the supremely arrogant species. We feel we can abandon four billion years of evolution and ignore the fact we have evolved under a light-dark cycle. What we do as a species is override the clock. And long-term acting against the clock can lead to serious health problems.’
Those who get less than five and a half hours a night consumed an average of 385 calories per day more than those who had more than seven hours.