The food consumption difference between those who sleep seven or more hours per night compared with those who sleep for less than seven hours per night works out to be the equivalent of four buttered slices of toast per day. In other words, a reduced period of sleeping is likely to make you fatter. In a sense the finding matches many people’s experiences: when we’re tired we tend to eat more food in order to provide more energy (or feelings of well-being) to get us through the day. Where the research introduces something new is just how much this food consumption difference is.
Of course the figure provided are averages, highlighting what two people of similar age and health who experience different sleep patterns might consume in a typical day when carrying out employment of a similar nature.
The finding emanates from a study conducted by scientists from King’s College London. The researchers discovered that people who are sleep-deprived consume an average of 385 calories per day more than those who slept for longer. Biochemically, sleep deprivation appears to affect the hormone ghrelin, which controls hunger; and the hormone leptin, which controls feelings of fullness.
Ghrelin is a peptide hormone and it functions as a neuropeptide in the central nervous system. In addition to regulating appetite, the hormone additionally plays a significant role in regulating the distribution and rate of use of energy. Leptin is a hormone made by adipose cells that helps to regulate energy balance by inhibiting hunger. In a healthy individual, the actions of ghrelin and leptin balance each other. However, when out of sync, as is apparent from sleep loss, increased feelings of hunger can arise.
The new research was based on a review of eleven observational studies, involving volunteers. Speaking with The Daily Telegraph, the lead author Study senior author Doctor Gerda Pot, explains: “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.”
The findings are published in the European Journal of Clinical Nutrition, with the study titled “The effects of partial sleep deprivation on energy balance: a systematic review and meta-analysis.”
