USA TODAY US Edition
Control weight by going to bed
Losing sleep doesn’t just leave you tired — it can make you fat
If you want to lose weight, be sure to get enough sleep.
Most people know they should cut calories and exercise more to trim down, but there’s now significant scientific evidence that another crucial component to weight control is avoiding sleep deprivation, sleep scientists say.
“There is no doubt that insufficient sleep promotes hunger and appetite, which can cause excessive food intake resulting in weight gain,” says Eve Van Cauter, director of the Sleep, Metabolism and Health Center at the University of Chicago. She has spent 15 years studying the topic.
Sleep deprivation probably affects every process in the body, Van Cauter says. “Our body is not wired for sleep deprivation. The human is the only mammal that does this.” Her research and that of others may help explain why so many people who are chronically sleep-deprived are also overweight, and how lack of sleep could be part of the reason college students, new parents and shift workers pack on pounds. HOW LACK OF SLEEP HURTS Studies show that when people don’t get enough sleep, they:
Have increased levels of a hunger hormone called ghrelin and decreased levels of the satiety/fullness hormone called leptin, which could lead to overeating and weight gain.
Consume 300 calories a day more than when they are rested. Overall, most of the extra calories came from high-fat foods.
Snack more and are less
Eat more than what is needed to cover the energy cost of staying awake longer, especially at night, which can lead to signifi-
“Insufficient sleep promotes hunger and appetite, which can cause excessive food intake.” Eve Van Cauter, director of the Sleep, Metabolism and Health Center at the University of Chicago.
cant weight gain.
Research has shown that when study subjects did not get enough sleep for five days, they consumed more carbohydrates and gained nearly 2 pounds in that time. “When people are sleepy, they make poor food choices and are more likely to eat more than they need,” says Kenneth Wright, director of the Sleep and Chronobiology Laboratory at the University of Colorado-Boulder.
When those folks got enough sleep, they cut their intake of carbohydrates and fats, Wright says.
Other research shows that too little sleep plays havoc with fat cells, which may lead to weight gain and diabetes, and that geting enough sleep helps fight a genetic predisposition to gain weight.
Van Cauter says sleep deprivation affects the body in many different ways. For instance, it activates a small part of the hypothalamus, the region of the brain that also is involved in appetite regulation.
In addition to ghrelin and leptin, other hormones involved in appetite regulation are affected by lack of sleep, she says. “We are looking at endocannabinoids, which are increased in the afternoon in people who are sleepdeprived. These hormones promote eating for pleasure, which is called ‘hedonic eating.’ ” FAT CELLS FEEL IT, TOO Another recent discovery: Lack of sleep reduces fat cells’ ability to respond properly to the hormone insulin, which is crucial for regulating energy storage and use, Van Cauter says. Plus, insulin promotes the release of leptin, so if your fat cells are less insulin-sensitive, you will make less leptin, which is associated with an increase in food consumption and weight gain, she says.
Insulin and leptin contribute independently to fat intake or storage, says Matthew Brady, an associate professor of medicine at the University of Chicago and the senior author of the study on sleep deprivation and fat cells. “There is a growing body of evidence that agrees that sleep deprivation can lead to greater chance of weight gain.”
Sleep needs vary, but in general, most young adults need seven to nine hours a night, says Van Cauter. There are some people who can do with less, and others who need more. With aging, sleep need decreases to about seven to eight hours a night, she says.