New research has identified a possible way to lose calories without closely monitoring diets or exercising more — simply by spending a little more time in bed, in fact.
In an experiment with 80 overweight adults who typically slept less than 6.5 hours per night, adding an average of 1.2 hours of extra sleep per night resulted in a reduction in overall caloric intake of an average of 270 calories per day.
Within two weeks of the experiment, caloric intake — the energy consumed via food and drink — decreased to less than the amount of calories burned by participants, which in the longer term would lead to weight loss.
The research takes the opposite approach to several previous studies that have successfully linked sleep deprivation to additional weight gain.
“Over the years, we and others have shown that sleep restriction affects appetite regulation, which leads to increased food intake and thus puts you at risk for weight gain over time,” says Esra Tasali, director of the University of Chicago. Sleep Center.
“More recently, the question everyone was asking was, ‘Well, if that’s what’s happening with sleep loss, can we prolong sleep and reverse some of these adverse effects?’ ”
If this reduction in caloric intake was maintained over three years, it would result in a weight loss of about 12 kilograms or 26 pounds over that time, the researchers said.
One advantage of the study is that it was conducted in a real-world environment, not a laboratory. Participants slept in their own beds, using wearable devices to track their sleep, and went through their days as usual, including what they ate and how much they exercised.
The volunteers used a urine test to track their caloric intake, currently considered the gold standard for measuring daily energy expenditure outside the laboratory. This involved drinking water in which hydrogen and oxygen atoms were replaced with other easily traced natural isotopes.
By comparing labeled water consumed by volunteers with unlabeled water from decomposed glucose, it is possible to accurately estimate calories taken in outside the lab.
Another notable part of the research was how quickly the group adjusted their sleep schedules — after just one counseling and advice session led by the research team, overall sleep duration was increased.
“We simply coached each individual on good sleep hygiene and discussed their own personal sleep environment, providing personalized advice on changes they could make to improve their sleep duration,” Tasali explains.
“It is important to note that to blind participants to the sleep intervention, the recruitment materials did not mention the sleep intervention, allowing us to capture true habitual sleep patterns at baseline.”
The researchers say that limiting the use of electronic devices before bed was one of the main ways to improve sleep behavior in the study. Participants were not informed that they were participating in a sleep intervention study when they enrolled.
What is not yet clear is exactly why this is happening, although, as noted, previous studies have found links between less sleep and increased appetite, so it is possible that the reverse is happening. In this case, most participants who slept more ate less.