A team at King’s College London (KCL) analysed results from previous similar studies and found that bleary-eyed people consumed an average of 385 kcal per day extra, equivalent to about four and a half slices of bread, in the 24 hours following sleep deprivation.
The study, published this week in the European Journal of Clinical Nutrition, found sleep deprived people had proportionately higher fat and lower protein intakes, but no change in carbohydrate intake.
Dr Gerda Pot, senior author from the Diabetes & Nutritional Sciences Division at KCL, said: “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.
“So there may be some truth in the saying ‘early to bed, early to rise, makes a man healthy and wise’.”
If long-term sleep deprivation continues to result in an increased calorie intake of this magnitude, it may contribute to weight gain, the study concluded.
More research is needed to investigate the importance of long-term, partial sleep deprivation as a risk factor for obesity and whether sleep extension could play a role in obesity prevention, the scientists said.