Work pressure, competition, shift works and hectic lifestyle, fueled with sleep loss is increasing the obesity charts; according to a new study. It concludes that the lack of sleep brings about physiological changes in the hormonal signals that promote hunger and perhaps leads to obesity.
Another similar study concludes that chronic sleep loss triggers hormones which can lower the appetite control hormone called leptin. Lower levels of leptin are associated with obesity. The researchers call it as “Ying Yang” of appetite control. The hormone ghrelin is produced in the stomach that triggers hunger. Leptin is produced be fat cells and signals satiety, telling the brain when we have eaten enough. The researchers investigated the effects of sleep loss on body mass index (BMI), an indirect measure of body fat. This was part of an ongoing sleep disorder study involving 1024 people, all between 30 and 60 years old.
Every four years, each volunteer came to a sleep laboratory for an overnight stay, with blood sampling and a check of BMI and weight. Every five years, each completed a questionnaire about sleep habits; they also kept a six-day “sleep diary”. During the 15-year study period researchers found that short sleep was associated with low leptin levels. The study shows a 15% increase in ghrelin and a 16% decrease in leptin in people who consistently got only five hours of sleep.
The researchers said, “it shows that there is a regulatory problem. Earlier when people are more active they needed to eat more calories, so it was a natural reaction of increased appetite and sleep as compared to today’s lifestyle, where people aren’t as physically active yet burning the candle at both ends, either in traffic or in front of the T.V. and also food is readily available. All these factors have caused increase in weight.”
The study also shows an association between sleep duration and BMI. Those getting three hours of sleep has a 5% increase in body weight. Getting a better night’s sleep and more exercise may well become a part of our future approach in combating obesity.