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How Sleep Can Help You Lose Weight
We all know that sleep is an important part of our lives; it rejuvenates us during the night and is central to a healthy metabolism. Without it we get cranky, our reflexes are less sharp and our brains do not perform as quickly. Sleeping well also contributes to maintaining a healthy weight. How? The answer is in your hormones.
Early findings of a study led by Professor Francesco Cappuccio at the University of Warwick Medical School in 2006 have linked lack of sleep with weight gain. Involving over 28,000 children and 15,000 adults, the study found that people who get less than five hours of sleep per night actually double their risk of becoming obese. Continued short sleep habits contributed to a greater Body Mass Index and a wider waist circumference over time. Professor Cappuccio identifies the greater risk of obesity to changes in hormone levels, specifically ghrelin and leptin. He is planning further studies to see whether fewer hours of sleep influences other diseases like diabetes or hypertension.
This is not the first study that has linked lack of sleep to obesity. In 2006, the Division of Kinesiology Department of Social and Preventive Medicine at Laval University in Quebec conducted a study based on similar hypotheses and found that children who slept even an hour or two less than other children became more obese. In 2004, Dr. Shahrad Taheri of the University of Bristol carried out a study on over 1000 adults, collecting data on sleep habits, and measuring ghrelin and leptin levels. These hormones are important for energy use and appetite regulation. It was discovered that individuals who slept fewer hours had higher ghrelin levels and lower leptin levels, and these fluctuations occurred during sleep.
Ghrelin and leptin are hormonal counterparts; ghrelin primarily stimulates appetitie, while leptin does the opposite. Ghrelin is produced by cells lining the stomach, usually in greater amounts before meals, and decreasing levels after. Ghrelin sends signals to the hypothalamus, in the brain, stimulating increased foot intake and fat mass. The hormone is also responsible for activating brain areas that respond to feel-good rewards like food. Lack of sleep increases the levels of ghrelin in the body, increasing your appetite and food intake. Leptin, on the other hand is produced by fat tissue. This hormone is responsible for regulating energy intake and use, by stimulating decreased appetite and increased metabolism. Leptin binds uniquely to the satiety centre of the hypothalamus, telling your brain you feel full. Higher leptin levels helps control appetite.
These sleep studies are analyzing one aspect of a broad range of lifestyle issues contributing to increasing obesity rates worldwide. Linking lack of sleep to increased weight may seem surprising. However, sleep and rest are times of intense healing and recuperation. Cutting those processes short can only do our bodies more harm than good. Without the proper R&R, it makes sense our bodies will need more energy, and thus more food. So add getting a good night's sleep to your weight-maintenance program!
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