The Correlation between Sleep Duration and Weight Gain
There’s no doubt that sleep is important. After all, everyone needs at least 6 hours of it every day. That’s seriously a long time of doing nothing. However, there’s something interestingly important everyone should know about sleep duration—you need enough of it to avoid weight gain.
A study conducted by researchers from Shanghai Jiao Tong University (China) and Indiana University (USA) found moderate evidence that sleep duration is inversely and longitudinally related to the risk of becoming overweight or obese among children and adolescents.(1) This study found that those who sleep longer were less likely to become overweight. The study compared more than 56,000 children and adolescents who sleep (shorter) with a duration of fewer than 10 hours and (longer) and approximately 12.2 hours.
2 Ways Sleep Duration can Impact Weight Gain
What could be the possible reason for this relationship between sleep duration and weight gain? A related research was conducted by researchers from Kao Corporation’s Health Care Food Research Laboratories and Waseda University.(2) They observed the effects of sleep duration on metabolism and appetite by observing 9 healthy men who were made to sleep a 3.5-hour duration and a 7-hour duration for three consecutive nights. They were then given a “recovery sleep night” (with 7 hours of sleep) after the three-night study period.
The researchers found that restricting sleep (shortening the duration of sleep) results in the reduction of gut hormones PYY (plasma peptide YY) and GLP-1 (plasma glucagon-like peptide). Sleep reduction can also lead to increased appetite or food craving. However, sleep deprivation does not appear to affect energy expenditure and substrate utilization although it tends to reduce core body temperature. These findings suggest that reduction of sleep duration impacts energy balance and circadian rhythms, that in turn leads to increased risk of obesity.
Simply put, shortened sleep duration raises weight gain risk as it makes the body crave for food while reducing metabolism (as manifested by the reduction in core body temperature). The body tends to have positive energy balance when sleep time is reduced.