A study that tracked 68,183 middle-aged women for a period of 16 years found that compared to women who slept 7 hours per night, women who slept for 5 hours per night were 32% more likely to experience major weight gain (an increase of 33 pounds or more) and 15% were more likely to become obese. Women who slept for 6 hours were 12% more likely to have major weight gain and 6% more likely to become obese.
Another study by Finnish researchers that followed more than 7,300 40-60 year olds between 2000-2002 for seven years found was that women who reported they had trouble falling asleep or difficulty staying asleep on at least 14 nights gained weight verus those women who didn’t. At the outset of the study 20% of women reported to having frequent sleep problems and those same women also reported a major weight gain of 11 pounds or more by the studies end.
The most recent study funded by the National Institutes of Health, Minnesota Obesity Center and the Mayo Clinic provides a glimpse into the reason why weright gain and lack of sleep may by linked. The study followed 17 healthy young men and women for eight nights with half of the participants sleeping normally and the other half sleeping only 2/3 of their normal sleep time. Both groups were allowed to eat whatever they wished during the experiment.
What researchers discovered was that the group that slept 1 hour and twenty minutes less than the control group consumed 549 additonal calories per day. Researchers also found that the amount of energy used wasn’t significantly different between the 2 groups, suggesting that those who slept 1 hour and twenty miniutes less didn’t burn additional calories.
The focus of the study was to determine whether lack of sleep affected hormone levels of leptin and ghrelin. Leptin is the hormone that tells you that you are full and to stop eating. When you are sleep deprived, you have LESS leptin. Gherlin is the hormone that tells your body that it is hungry and when you are sleep deprived you have MORE gherlin. More gherlin + less leptin =weight gain.
Even though this was a small study it’s implications are large, especially for people who don’t make sleep a priority or for those people who expereince difficulty falling asleep or staying asleep. Read some tips here for getting a good nights sleep.