You snooze, you lose - really
Sept. 12, 2006 12:00 AM
The back story: Strange as it may seem, researchers are finding that if you snooze, you'll lose pounds. Americans have been losing sleep for years. On average, they sleep one to two fewer hours per night than they did 40 years ago. At the same time, rates of obesity have skyrocketed. Coincidence? Researchers think not.
What advocates claim: Sleep affects a variety of hormones related to weight regulation. When you don't get enough sleep, your body produces less growth hormone and leptin. Growth hormone inhibits weight gain and controls proportions of fat and muscle. Leptin tells the body when it has had enough to eat. People with low levels of leptin not only want to eat more, they also crave more carbohydrates. In addition, insufficient REM sleep may increase cortisol, a stress hormone that increases appetite.
What we know: A number of large studies have found a correlation between sleep loss and weight gain.
In a study published in 2004, Emmanuel Mignot of Stanford University investigated the effects of sleep loss on body mass index as part of a sleep disorder study involving 1,024 Wisconsin state employees. During the 15-year study, those getting three hours of sleep had a 5 percent increase in body weight.
The largest investigation to date was part of the Nurses' Health Study, which included more than 68,000 healthy women. Over the course of 16 years, women who reported sleeping five hours or less per night gained 2.3 pounds more than those who slept seven hours. Major weight gain, of about 30 pounds, was most common among women who slept five hours per night. They were followed by the six-hour-a-night sleepers.
In their analysis, researchers adjusted for age, physical activity and dietary behaviors.
Researchers don't completely understand how sleep and weight gain are related. Nor do they know which comes first: unhealthy sleep habits or weight gain. It's possible that people who get plenty of sleep at night have other factors that keep their weight lower.
Until these questions are answered, some experts remain skeptical. But most agree that if you are dieting, logging in a few extra hours of sleep a week isn't a bad idea.
Sept. 12, 2006 12:00 AM
The back story: Strange as it may seem, researchers are finding that if you snooze, you'll lose pounds. Americans have been losing sleep for years. On average, they sleep one to two fewer hours per night than they did 40 years ago. At the same time, rates of obesity have skyrocketed. Coincidence? Researchers think not.
What advocates claim: Sleep affects a variety of hormones related to weight regulation. When you don't get enough sleep, your body produces less growth hormone and leptin. Growth hormone inhibits weight gain and controls proportions of fat and muscle. Leptin tells the body when it has had enough to eat. People with low levels of leptin not only want to eat more, they also crave more carbohydrates. In addition, insufficient REM sleep may increase cortisol, a stress hormone that increases appetite.
What we know: A number of large studies have found a correlation between sleep loss and weight gain.
In a study published in 2004, Emmanuel Mignot of Stanford University investigated the effects of sleep loss on body mass index as part of a sleep disorder study involving 1,024 Wisconsin state employees. During the 15-year study, those getting three hours of sleep had a 5 percent increase in body weight.
The largest investigation to date was part of the Nurses' Health Study, which included more than 68,000 healthy women. Over the course of 16 years, women who reported sleeping five hours or less per night gained 2.3 pounds more than those who slept seven hours. Major weight gain, of about 30 pounds, was most common among women who slept five hours per night. They were followed by the six-hour-a-night sleepers.
In their analysis, researchers adjusted for age, physical activity and dietary behaviors.
Researchers don't completely understand how sleep and weight gain are related. Nor do they know which comes first: unhealthy sleep habits or weight gain. It's possible that people who get plenty of sleep at night have other factors that keep their weight lower.
Until these questions are answered, some experts remain skeptical. But most agree that if you are dieting, logging in a few extra hours of sleep a week isn't a bad idea.