A new study led by the University of Chicago and the University of Wisconsin-Madison has found that getting more sleep can reduce caloric intake, and thus lead to weight loss, without sustained control over dietary habits or increases in the frequency or intensity of physical exercise.
In a randomized clinical trial with 80 adult participants, a team of researchers led by Dr. Esra Tasali, the director of the University of Chicago’s Sleep Research Center (SRC), has helped young, overweight adults who habitually slept fewer than 6.5 hours per night to increase their sleep duration by an average of 1.2 hours per night through a personalized sleep hygiene counselling session.
“We saw that after just a single sleep counseling session, participants could change their bedtime habits enough to lead to an increase in sleep duration,” said Dr. Tasali. “We simply coached each individual on good sleep hygiene, and discussed their own personal sleep environments, providing tailored advice on changes they could make to improve their sleep duration. Importantly, to blind participants to sleep intervention, recruitment materials did not mention sleep intervention, allowing us to capture true habitual sleep patterns at baseline.”
Dr. Tasali and her colleagues monitored participants’ caloric intake both before and after the change in their sleeping patterns, and found that the increase in sleep duration helped participants reduce this intake by an average of 270 kilocalories per day – which would translate to roughly 12 kg of weight loss over three years if the effects were maintained over a long term.
“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 Dr. Tasali. “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?”
Further research is needed to clarify the underlying mechanisms explaining these results, and to design larger studies on weight control to determine if extending sleep could be of use in weight-loss programs and help prevent or reverse obesity.
“Many people are working hard to find ways to decrease their caloric intake to lose weight – well, just by sleeping more, you may be able to reduce it substantially,” concluded Dr. Tasali.
The study is published in the journal JAMA Internal Medicine.