If your clients are trying to lose or maintain weight, let them know about this new research. Sleep deprivation may lead to higher calorie consumption the next day, according to a systematic review and meta-analysis led by researchers at King’s College London. The meta-analysis found that sleep-deprived people consumed an average of 385 extra kilocalories per day, equivalent to about 4.5 slices of bread.
Published in the November 2, 2016, issue of the European Journal of Clinical Nutrition, the study combined the results of 11 smaller studies with a total of 172 participants. The studies that were included had compared partial sleep restriction with unrestricted sleep (control group) and measured energy intake over the following 24 hours.
Partial sleep deprivation had no significant effect on how much energy participants expended in the subsequent 24 hours. Therefore, there was a net energy gain of 385 calories per day. If long-term sleep deprivation continued to result in a calorie intake of this magnitude, it could contribute to weight gain. The researchers also observed a small shift in what sleep-deprived people ate—they ate proportionately more fat and less protein, but their carbohydrate intake didn’t change.
Dr. Gerda Pot, senior author from the Diabetes & Nutritional Sciences Division at King’s College London and Vrije Universiteit Amsterdam, 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.’
“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. 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.”
A previous small study in 26 adults found partial sleep deprivation resulted in greater activation of areas in the brain associated with reward when people were exposed to food. A greater motivation to seek food could be an explanation for the increased intake seen in sleep-deprived study participants, the authors suggested. Other possible explanations include disruption of the internal body clock, thus affecting the regulation of leptin (the “satiety” hormone) and ghrelin (the “hunger” hormone).
The amount of sleep restriction varied between the studies, with the sleep-deprived participants sleeping 3.5–5.5 hours in the night. The control subjects spent 7–12 hours in bed.
The authors suggested that more intervention studies are needed—over longer periods and in everyday-life settings—as most studies included in this analysis took place in controlled laboratory conditions over periods of 1 day to 2 weeks.
Haya Al Khatib, lead author and PhD candidate at King’s College London, 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 randomized controlled trial in habitually short sleepers to explore the effects of sleep extension on indicators of weight gain.”