Who told us that we are supposed to exercise, eat right and get a good night’s sleep? On average, people need between seven and nine hours of sleep per night. Unfortunately, according to the National Sleep Foundation, only 63% of American adults do not get the recommended eight hours of sleep. How much sleep do Americans get? The same study found the average adult gets 6.9 hours of sleep during the week and 7.5 hours on the weekends yielding an average of 7 hours per night. How much sleep do you get?
Recent media attention has brought to light research suggesting a link between sleep and hormones that influence eating behavior. Multiple studies have found sleep deprivation increases levels of a hunger hormone (ghrelin) and decrease levels of a hormone that makes a person feel full (leptin). What does this mean? Sleep deprivation leads to a stimulated appetite.
Leptin and ghrelin work together in a “checks and balances” type system. Ghrelin is an appetite-stimulating hormone released mostly by the stomach and makes a person feel hungry when levels are elevated. Leptin is a satiety or fullness hormone released by fat cells and sends messages to the brain about current body energy balance.
A study at the University of Wisconsin found that people who regularly slept five hours per night had a 14.9% higher level of ghrelin and a 15.5% lower level of leptin than those who slept eight hours—leaving them feeling unsatisfied and hungry. In a separate study at the University of Chicago restricted sleep led to lowered levels of leptin and increased ghrelin with participants’ appetites increasing proportionately. These participants reported a 45% increase in desire for high carbohydrate, calorie-dense foods. Finally, researchers at Columbia university reviewed data on 6,115 individuals and found people who slept 2-5 hours per night were 63% more likely to be obese than those who got 7-9 hours. Those who got 5 hours were 50% more likely and those who got 6 hours, respectively, were 23% more likely to be obese than “normal” sleepers.
The take home message: exercising, eating right, and getting good sleep matter!