Sleeping habits linked to increase in obesity

Getting a bad night's sleep could be increasing some people's likelihood of becoming obese.‌‌ According to a study led by the University of Glasgow, and published today in the American Journal of Clinical Nutrition (AJCN), abnormal sleeping habits increase the risk of obesity for those who are genetically predisposed to being overweight. The findings, based on data from the UK Biobank, emphasise that while genetics have a large role to play in obesity, lifestyle also plays an important role. Researchers looked at the effects of abnormal sleeping habits such as short sleep duration (less than 7 hours sleep a night) and long sleep duration (more than 9 hours sleep a night), along with daytime napping and shift work. The study, which is the first of its kind to examine the interactions of sleeping habits and genes with obesity, found that in people with high genetic risk for obesity, both short sleep durations (less than 7 hours per night) and long sleep durations (more than 9 hours per night) further increased risk of carrying excess weight, compared with those who slept for normal durations (between 7 and 9 hours every night). Long sleepers with high genetic risk of obesity were about 4 kg heavier, and short sleepers were about 2 kg heavier, than those with similarly high genetic obesity risk with normal sleep durations. In contrast, there was no clear link between sleep duration and body weight in those with a low genetic risk of obesity. The negative effect of abnormal sleep on someone already predisposed to obesity happened irrespective of diet, health concerns or socio-demographic factors.