CalorieLab Calorie Counter News today reported on an article in the Center for Science in the Public Interest newsletter that suggests sleep time - or lack of adequate sleep - is correlated with a higher body weight. In a study conducted in New York, researchers found that those who slept 6-hours or less a night were 23% more likely to be obese than those who slept 7 to 9-hours a night.
One possible explanation is hormones - specifically leptin and ghrelin - that regulate eating. Sleep affects the production of both hormones and a lack of sleep may be affecting how the two are regulated in the body. The article also puts forth the possibility that more awake time provides more time to eat as a possible explanation, along with potential skewing of the data with sleep apnea in more obese people than normal weight people.
Quite frankly the article failed to dig deeper into the role sleep plays in our weight and health. There is ample evidence available to provide more insight to readers about the importance of sleep and the potential reasons lack of sleep may increase weight and have a negative impact on overall health.
We know, for example, that it is during sleep that the body takes time to repair and build tissue - something it cannot do effectively during waking hours. If we short-change the body of sleep, it will make due with the sleep it has, but will not be working at optimal levels for health.
We also know that it is through sleep that the body addresses inflammation, something that in the long-term is detrimental to the body. Without adequate sleep, inflammation may persist and continue to do damage or grow worse.
Lack of sleep time is also associated with higher incidence of diabetes and insulin resistance, both associated with a much higher prevalence of obesity. In a study published back in April in the Archives of Internal Medicine, researchers found a similar association in sleep time as noted above with the association tied to diabetes and insulin resistance, not simply weight. In that study, those who slept less than 6-hours a night had an increased prevalence of diabetes and insulin resistence when compared with those who slept 9-hours a night. The researchers noted, Because this effect was present in subjects without insomnia, voluntary sleep restriction may contribute to the large public health burden of DM.
Sleep is important to our health - it allows the body to recharge and regenerate; reduce overall stress and inflammation; and wake with the body ready for the day instead of trying to just make do with too little sleep.