“Getting More Sleep Reduces Caloric Intake, a Game Changer for Weight Loss Programs”
(University of Chicago press release revised by Dale Schoeller, co-author of the JAMA paper and Director of the Isotope Ratio Mass Spectrometry (IRMS) Laboratory)
A new study about how sleep affects caloric intake could change how people think about – and approach – weight loss. In a randomized clinical trial of 80 adults, a team of researchers from University of Chicago and the University of Wisconsin–Madison found that overweight adults who increased their nightly sleep duration by about an hour reduced their daily caloric intake by an average of 270 calories, to the point where they were burning more calories than they were taking in overall.
The study’s findings, published Feb. 7 in JAMA Internal Medicine, found that young, overweight adults who habitually slept fewer than 6.5 hours a night were able to increase their sleep duration by an average of 1.2 hours per night after a personalized sleep hygiene counseling session. The sleep intervention, which was intended to extend time in bed duration to 8.5 hours, reduced participants’ overall caloric intake by an average of 270 calories per day compared to controls.
“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,” said lead investigator Esra Tasali, MD, director of the Sleep Center at the University of Chicago Medicine. “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?’”
This study was only possible due the ability to accurately and objectively measure energy intake. To do this, Dale Schoeller measured the sum of energy expenditure plus change in body energy stores. Energy expenditure was measured using the stable isotope, doubly labeled water method. Schoeller was the first to use method in humans. Water labeled with 2H and 18O is orally administered to the participant. The 18O is distributed across the body water pool and the bicarbonate pool and is eliminated as water and CO2. The 2H distributes in body water and is eliminated only as water. The difference between the two elimination rates is proportional to CO2 production and hence the rate of energy expenditure. A major advantage of the doubly labeled water method is that an investigator does need to collect expire CO2, but can simply measure that 2H and 18O enrichments in the person’s blood or urine at the start and end of the metabolic period. The change in body energy stores was measured over the same two weeks by serial DXA measurements.
“This was too short to qualify as weight-loss study,” said Tasali. “But we have quantified evidence showing a decrease in caloric intake and a negative energy balance — caloric intake is less than calories burned. If healthy sleep habits are maintained over longer duration, this would lead to clinically important weight loss over time. Many people are working hard to find ways to decrease their caloric intake to lose weight and by just sleeping more, you may be able to reduce it substantially.”