The statistics are alarming: About 65% of Americans are now overweight or obese, according to the Centers for Disease Control and Prevention. The number of obese adults jumped from 15% in 1980 to 27% in 1999. This trend doesn’t seem to be changing anytime soon: the estimate is that 75% of the U.S. population will be overweight or obese by 2020.
The basic problem has been growing for a long time: an energy imbalance due to the availability of caloric-rich food and decreasing energy expenditures as a result of sedentary lifestyles in an industrialized society.
“A hundred and fifty years ago, a sedentary lifestyle was considered to be that of a farmer’s wife,” says Richard Simon, MD, a sleep specialist in Walla Walla, WA. “Our levels of physical activity have plummeted, along with our caloric expenditure, yet our caloric intake has not declined. When caloric expenditure declines and caloric intake does not decline, weight gain occurs.
But that’s not the entire picture. Scientists have learned about another important factor that was not evident until recently: insufficient sleep. They found compelling evidence that sleep loss leads to metabolic disturbances which increase the positive energy imbalance and result in weight gain.
“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. “There are epidemiology studies and population studies that show that the success of a weight loss diet is compromised when sleep is insufficient. To try to reduce dietary intake and reduce calories while sleep deprived is like rollerblading uphill. You can do it, but it takes a lot more effort and your chances of arriving there are compromised”.
Recent studies of healthy volunteers with normal weights show that even short periods of sleep deprivation lead to metabolic disturbances of sugars as well as increased appetites.Kenneth Wright, director of sleep and chronobiology laboratory at the University of Colorado in Boulder, notes, “When people are sleepy, they make poor food choices and are more likely to eat more than they need.”
Additionally, researchers at BYU found strong links between getting high-quality, sufficient sleep and lower body fat. Getting less than 6.5 hours of sleep and more than 8.5 hours of sleep was linked to higher body fat. The quality of sleep also matters because high quality sleep was associated with lower body fat while poor sleep correlated with higher body fat. The strongest link to lower body fat was consistency — waking and going to sleep at the same time every day.
We need to change our relationship to sleep and see it as an essential component of fitness and physical health. Weight-loss is not just about nutrition and physical exercise – it’s also about taking care of your body with proper rest.
Find out more about how you can reach your weight-loss goals through better sleep with our Sleep-Life Balance Program.