Lack of Sleep Leads to Excess Calories

Recent research from King's College shows that not getting enough sleep can make you eat more calories than you burn.

Quite a lot more.

On average, a whopping 385 calories, that would take most people more than an hour of pretty intense exercise to burn off. And would be enough for an extra lunch - not what you want if you're trying to keep your weight under control.

If it happened every day, that's more than enough calories to put on over half a pound a week. The researchers found no significant increase in energy expenditure in the sleep deprived. So, weight gain is an almost inevitable outcome.

There’s a body of evidence building up showing that lack of sufficient sleep can lead to weight gain. For an in depth look at the evidence see our article Sleep and Weight Loss.

The Study

For the Kings College study, researchers reviewed and analysed the results of 11 studies involving 172 participants.

The amount of sleep restriction varied between the studies. Sleep deprived participants sleeping between three and a half and five and a half hours a night, and consumed an extra 385 calories.

The researchers also found there was a small shift in the types of food sleep deprived people ate. They had higher fat and lower protein intakes, but no change in carbohydrate intake.

Study author Dr Gerda Pot 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."

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 food intake seen in sleep deprived people in this study, the authors suggest.

Other possible explanations include a disruption of the internal body clock affecting the body's regulation of leptin (the 'satiety' hormone) and ghrelin (the 'hunger' hormone).

"Our results highlight sleep as a potential third factor, in addition to diet and exercise, to target weight gain more effectively." Said lead author Haya Al Khatib, PhD candidate at King's College London.

References and Sources

Kings College London Press Release

The effects of partial sleep deprivation on energy balance: a systematic review and meta-analysis European Journal of Clinical Nutrition