Summary: A pooled analysis of randomized trials followed 95 adults who reduced their nightly sleep by roughly 80 minutes for six weeks. Even this modest, chronic-like sleep loss produced measurable metabolic and behavioral changes: participants gained about one pound on average and increased daily sedentary time. When projected over a year, losing less than an hour and a half of sleep per night could contribute to meaningful weight gain, higher insulin resistance, and increased cardiac inflammation.
This study models a common modern pattern—regularly getting 5–6 hours of sleep—and shows that even mild, sustained sleep restriction alters energy balance and health markers linked to obesity, diabetes, and heart disease.
Key Facts
- Real-world sleep change: Unlike older studies that forced extreme sleep deprivation (for example, four-hour sleep opportunities), this trial delayed participants’ bedtimes by 90 minutes to reproduce the more common pattern of chronically shortened sleep experienced by many working adults.
- Weight gain within weeks: Participants shortened their sleep by an average of 78–80 minutes per night. Over six weeks that modest reduction corresponded to an average weight increase of about 0.45 kg (approximately one pound).
- Rise in sedentary behavior: Daily sedentary time increased by 17 minutes on average during the sleep-restriction phase.
- Groups at higher risk: Men and postmenopausal women showed larger increases in sedentary time—nearly 30 extra minutes per day—when sleep was curtailed.
- Not simply more awake time: The increase in inactivity could not be explained only by being awake for more hours. Even after adjusting for longer wake time, participants chose to spend more of their daytime inactive when they had less sleep.
- Metabolic and cardiac signals: Related analyses from the same cohort found increased insulin resistance—especially in postmenopausal women—and evidence of inflammatory cell influx into heart tissue among adults with elevated cardiac risk after six weeks of mild sleep restriction.
Source: Columbia University
Main finding: Reducing nightly sleep by about 80 minutes for six weeks led to modest but meaningful changes: average weight gain of one pound and increased sedentary time. These shifts may accumulate and raise long-term risk for cardiometabolic disease.
“Our study indicates that maintaining adequate sleep may help prevent weight gain and reduce risk for obesity-related conditions such as heart disease and type 2 diabetes,” says Marie-Pierre St-Onge, professor of nutritional medicine at Columbia University and lead investigator. “Relying solely on diet and exercise without addressing sleep is simplistic and may not be sustainable for many people.”
Why study mild, chronic sleep loss?
Previous experimental work often used severe and short-term sleep deprivation to reveal mechanisms driving hunger and overeating. Those studies are informative but less applicable to the millions of adults who habitually sleep only 5–6 hours per night. This trial was designed to test whether a smaller, sustained reduction in sleep—more representative of everyday life—also affects body weight, activity, and metabolic health.
Study design and outcomes
Ninety-five adults with habitual sleep of seven or more hours and at elevated cardiometabolic risk participated in two six-week phases: one with sustained adequate sleep and one with sleep restricted by 1.5 hours per night, separated by a washout period. Sleep and activity were monitored continuously with wrist devices; body weight, waist circumference, body composition (including whole-body volume by imaging), hormones related to appetite, and other biomarkers were measured throughout.
Compared with adequate sleep, sleep restriction shortened nightly sleep by about 78.4 minutes (95% CI, −83.5 to −73.3 minutes). Body weight increased by 0.45 kg (CI, 0.33 to 0.57 kg), waist circumference by 0.52 cm (CI, 0.25 to 0.79 cm), and whole-body volume by 0.56 L (CI, 0.19 to 0.93 L). Leptin, a hormone linked to energy balance, rose by 2.03 ng/mL (CI, 0.38 to 3.68 ng/mL). Sedentary time increased by 17.2 minutes per day (CI, 11.7 to 22.7 minutes).
Lead author Faris Zuraikat emphasizes that a one-pound gain over six weeks may seem small in isolation, but when placed in the context of habitual sleep loss and extrapolated over months to years, it could produce clinically significant increases in body weight and cardiometabolic strain.
Key Questions Answered:
A: The concern lies in the pattern and timeline. This weight gain occurred from a modest, routine bedtime delay over a short window. Because the sleep change modeled is common and persistent for many adults, the small six-week gain can compound across months and years into substantial, clinically meaningful weight increases that strain metabolism.
A: Sleep restriction produced greater daytime fatigue and reduced spontaneous movement. Even after accounting for the extra wake time, participants spent more of their day inactive, suggesting mild sleep loss diminishes motivation and energy for physical activity—an “inactivity paradox” with health implications.
A: Sleep plays an active role in hormone regulation, glucose metabolism, and inflammation control. In related analyses from this cohort, mild sleep restriction increased insulin resistance—particularly in postmenopausal women—and promoted infiltration of inflammatory cells into heart tissue among individuals with elevated cardiac risk, linking even modest sleep loss to pathways involved in type 2 diabetes and cardiovascular disease.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- The journal article was reviewed in full by staff.
- Additional context was added by the editorial team.
About this sleep and weight gain research news
Author: Helen Garey
Source: Columbia University
Contact: Helen Garey – Columbia University
Image: Image credited to Neuroscience News
Original Research: “Skimping on Sleep and Its Impact on Body Weight and Composition: A Pooled Analysis of Randomized Trials,” Annals of Internal Medicine. DOI: 10.1016/j.scib.2026.05.040
Abstract
Skimping on Sleep and Its Impact on Body Weight and Composition: A Pooled Analysis of Randomized Trials
Background:
Insufficient sleep is linked to obesity, but the causal effect of chronic, mild sleep shortfall—and whether this effect varies by sex or menopausal status—remains unclear.
Objective:
To assess how six weeks of nightly sleep restriction by 1.5 hours affects energy balance and body weight regulation.
Design:
Pooled analysis of two randomized crossover trials.
Setting:
Outpatient intervention with both inpatient and outpatient assessments.
Participants:
Adults (n = 95) aged 20 years or older at elevated cardiometabolic risk who habitually slept seven or more hours per night.
Intervention:
Six weeks of sustained adequate sleep and six weeks of sleep restriction of 1.5 hours per night, separated by a multiweek washout.
Measurements:
Adiposity (magnetic resonance imaging), body weight, waist circumference, energy-balance behaviors, and related biomarkers were assessed.
Results:
Sleep was reduced by 78.4 minutes per night with restriction. Relative to adequate sleep, sleep restriction increased body weight by 0.45 kg, waist circumference by 0.52 cm, and whole-body volume by 0.56 L. Leptin rose by 2.03 ng/mL, and sedentary time increased by 17.2 minutes per day.
Limitations:
The intervention length may have been too short to detect larger body composition changes; power to examine subgroup differences was limited; effect sizes were modest.
Conclusion:
Sustained, moderate sleep restriction may promote weight gain. Programs for weight management and cardiometabolic disease prevention should consider incorporating strategies to promote adequate sleep.
Primary Funding Source:
National Institutes of Health and the American Heart Association.
Authors (all from Columbia unless noted): Faris Zuraikat, Samantha Scaccia, Justin Cochran, Bin Cheng, Keith Diaz, Seth Creasy (University of Colorado), Brooke Aggarwal, Sanja Jelic, and Marie-Pierre St-Onge. The authors report no conflicts of interest.