It doesn’t take a dramatic all-nighter to tip the scales — just a modest, chronic sleep shortfall may be enough, according to a new study from Columbia University Irving Medical Center that adds fresh evidence to the link between sleep and body weight.
Researchers pooled data from two randomized crossover trials involving 95 adults age 20 and older, all of whom had elevated cardiometabolic risk factors and typically slept at least seven hours a night. Each participant spent six weeks sleeping their usual amount and six weeks with sleep intentionally curtailed by about 90 minutes nightly — mimicking the kind of routine sleep loss many adults experience from work, parenting, or screen time rather than a formal sleep disorder.
Using wrist-worn actigraphy to track sleep objectively, the team found participants actually lost an average of 78 minutes of sleep per night during the restriction phase. The result: participants gained close to a pound of body weight on average, along with a modest increase in waist circumference, compared with their well-rested phase.
“Our study shows that getting adequate sleep may help reduce the risk of weight gain and obesity-related conditions like heart disease and diabetes,” said Marie-Pierre St-Onge, a professor of nutritional medicine at Columbia and the study’s senior author. “People tend to gain weight over the course of their adulthood, and obesity is a major risk factor for heart disease.”
What stood out to researchers was not a surge in appetite, but a drop in movement. Sedentary time rose by an average of 17 minutes a day during the sleep-restricted phase — and by nearly 30 minutes a day among men and postmenopausal women — even after accounting for the extra waking hours sleep loss created. Total daily calories burned, measured using the gold-standard “doubly labeled water” method in a subset of participants, stayed essentially flat, reinforcing that reduced activity, not increased eating, appeared to be driving the modest weight change. Fasting levels of leptin, a hormone that helps regulate hunger and energy balance, also rose in step with the added weight.
Study lead author Faris Zuraikat, an assistant professor of nutritional medicine at Columbia, said the findings are especially notable given the study’s short time frame. “While the one-pound weight gain observed with modest sleep curtailment is not overwhelming, it is important to remember this is occurring over just six weeks,” he said. “When extrapolated to a full year, we would expect that losing less than an hour and a half of sleep per night could result in clinically meaningful weight gain.”
The findings, published in the Annals of Internal Medicine, add to a growing body of Columbia research linking mild sleep loss to worsening metabolic markers, including increased insulin resistance and inflammatory changes in the heart. Researchers say the takeaway for clinicians is straightforward: sleep duration deserves a routine place in conversations about weight management, alongside diet and exercise.
