MORNINGSIDE HEIGHTS, N.Y., July 28 (Our New York News) — Cutting sleep by about an hour and a half a night may sound like a small sacrifice, but Columbia University researchers in New York City say it can add up. In a study published in Annals of Internal Medicine, adults who slept less for six weeks gained about 1 pound on average, saw a slight increase in waist size and spent more time being sedentary.
For people trying to manage weight, the takeaway is simple: sleep may matter more than many routines give it credit for. The change the Columbia team measured was modest over six weeks, but the researchers said the pattern could become more meaningful over time.
What the study found
The Columbia team reported that participants who shortened sleep by roughly 80 to 90 minutes per night gained about 1 pound on average during the sleep-restriction phase. Their waist circumference, a tape-measure estimate around the midsection, rose by about 0.52 centimeters, or about half a centimeter.
The study also found that participants became more sedentary. Columbia said sedentary time rose by an average of 17 minutes a day overall. Among men and postmenopausal women, the increase was nearly 30 minutes a day.
Why researchers say that matters
The study was designed to reflect sleep patterns many adults live with chronically, according to Columbia University Vagelos College of Physicians and Surgeons. Faris Zuraikat, an assistant professor of nutritional medicine at Columbia, said the short-term gain was not dramatic, but it came from only six weeks of less sleep.
“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,” Zuraikat said in Columbia’s release.
He added: “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.”
What this does and does not show
The findings come from a specific group of adults already at elevated risk for heart or metabolic disease, so they should be read as evidence from that group rather than a guarantee for every adult.
The study shows that shorter sleep was linked with more sitting and small weight gain over a six-week period. It does not show that one short night by itself causes pounds to pile on.
Still, for everyday weight management, the research suggests that sleep is not just about feeling rested the next day. Over time, Columbia’s team says, losing a little sleep each night may quietly nudge weight and waist size in the wrong direction.
