February 07, 2022
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Going to bed at the same time each night, regardless of whether it falls on a weeknight or weekend, can help people get better sleep.
Diet and exercise are the gold-standard weight loss solutions, but getting enough sleep also may help.
Scientists have known chronic sleep deprivation can contribute to weight gain. A new study suggests that getting just an extra hour of sleep could reduce daily caloric intake by 270 calories. Some participants ate as much as 500 fewer calories a day.
"The current obesity epidemic, according to experts, is mostly explained by an increase in caloric intake, rather than lack of exercise," said Dr. Esra Tasali, director of the UChicago Sleep Center at the University of Chicago Medicine.
Sleep loss is one of the risk factors for obesity, according to the Sleep Foundation.
Sleep deprivation affects the balance of leptin and ghrelin, two hormones that regulate appetite. This leads to increased feelings of hunger and overeating. Poor sleep also can slow down the body's metabolism. Plus, people with poor sleep habits tend to be too tired to exercise regularly.
All this creates a perfect storm for unwanted weight gain, experts say. Obesity itself can cause sleep issues, which in turn leads to more weight gain, creating a frustrating cycle for people trying to lose weight.
The study focused on increasing the sleep duration of 80 young, overweight adults who slept less than 6.5 hours per night. They ultimately increased their sleep duration by 1.2 hours per night after a personalized counseling session on sleep hygiene. And this extra sleep decreased their overall caloric intake.
These new sleep routines would result in the loss of 26 pounds over three years – if they were maintained, researchers said.
"Over the years we and others have shown that sleep restriction has an effect on appetite regulation that leads to increased food intake, and thus puts you at risk for weight gain over time," Tasali said. More recently, the question that everyone was asking was, 'Well, if this is what happens with sleep loss, can we extend sleep and reverse some of these adverse outcomes?'"The researchers hailed their findings as game-changing because the study was conducted in a real-world setting rather than a laboratory. The participants slept in their own beds and followed their normal lifestyles without any special diets or exercise instructions.
"Most other studies on this topic in labs are short-lived, for a couple of days, and food intake is measured by how much participants consume from an offered diet," Tasali said. "In our study, we only manipulated sleep, and had the participants eat whatever they wanted, with no food logging or anything else to track their nutrition by themselves."
The researchers said they were most surprised that it just took one sleep counseling session for participants to substantially change their bedtime habits. The researchers simply coached each individual on good sleep hygiene and discussed ways to improve their sleep environments.
The study was conducted over four weeks. During the first two, the research team gathered baseline data on sleep and caloric intakes. During the next two weeks, they monitored the effects of the sleep intervention.
Their sleep was tracked using wearable devices. Their caloric intakes were measured with a urine-based test considered the gold standard for objectively measuring daily energy expenditure in real-world settings.
If improved sleep duration is maintained over a longer period of time, a person could lose a significant amount of weight simply by sleeping more, Tesali said.
The U.S. Centers for Disease Control and Prevention recommends several tips for improving sleep hygiene. Among them:
• Be consistent. Try going to bed at the same time every night, regardless of whether it falls during the middle of the week or weekend. Also try to get up at the same time each morning.
• Remove electronic devices, including computers, televisions and smart phones, from the bedroom.
• Get regular exercise. Physical activity can help people fall asleep more easily at night.
The researchers plan additional studies to better understand the underlying mechanisms behind their findings. Because this was not a weight-loss study, Tesali said larger studies will be needed on whether extending sleep can support weight-loss programs and help prevent or reverse obesity.
The study findings were published in JAMA Internal Medicine.
