In young adults sleep deprivation has been found to cause fat accumulation in the belly for the first time.
Naima Covassin from the Mayo Clinic Rochester Minnesota studied 12 healthy slim young people aged between 19 and 39. The poor souls were randomised to two weeks of just 4 hours sleep a night or 9 hours sleep followed by a three day recovery period. During this time the subjects were kept in hospital and factors such as calorie intake and energy output were measured.
Over the two weeks of sleep deprivation, the subjects put on an average of a pound or half a kilogram and all of it on the belly.
This was because they consumed an extra 308 calories a day compared to the 9 hours a night group.
Despite stopping the study after two weeks and then during recovery sleeping more, eating fewer calories and their total weight coming down, their bellies continued to get bigger, by an average of 3 cm by day 21 of the study.
This could be why shift workers are so prone to gaining fat around the belly.
The continued rise in belly fat could have been missed if body weight, BMI and overall body fat percentage were the only factors measured.
Dr Harold Bays who is an endocrinologist and president of the Louisville Metabolic and Atherosclerosis Research Centre says “Sleep disruption results in fat dysfunction and this may result in increased cardiovascular risk factors and unhealthy body composition including an increase in visceral fat.”