Summary: A pooled analysis tracked 95 adults who shortened their nightly sleep by a modest 80 minutes over six weeks. The researchers discovered that this minor deprivation is a potent metabolic disruptor: over the short six-week window, participants gained an average of one pound and experienced a significant daily spike in sedentary behavior.
When extrapolated across a full year, losing less than an hour and a half of sleep per night acts as a direct catalyst for clinically meaningful weight gain, elevated insulin resistance, and cardiac inflammation.
Key Facts
- The Mimicked Chronic Reality: Unlike past studies that used unsustainable, extreme sleep limits (such as four hours of sleep opportunity), this trial intentionally delayed participants’ bedtimes by 90 minutes to mirror the common 5-to-6-hour sleep pattern chronically adopted by millions of working adults.
- The One-Pound Six-Week Compounder: By delaying their bedtimes, participants shortened their actual sleep by an average of 80 minutes a night. Over just six weeks, this subtle restriction drove an average weight gain of one full pound. Lead author Faris Zuraikat warns that when extrapolated over a full calendar year, this trend points to major, insidious weight gain.
- The Sedentary Spike: Inactivity levels rose significantly during the sleep-restriction phase, with participants spending an average of 17 extra minutes per day being entirely sedentary.
- Demographic Vulnerability: The drive toward inactivity was even more severe for specific groups: men and postmenopausal women logged an average spike of nearly 30 additional minutes of daily sedentary time when mildly sleep-deprived.
- The Inactivity Paradox: Notably, this rise in sedentary behavior could not be blamed on simply being awake longer. Even after mathematically accounting for the extra hours spent awake due to a delayed bedtime, participants still actively chose to spend more time being physically inactive.
- The Pre-Diabetes & Cardiac Risk Cascade: This study builds on a series of related findings from the same cohort. St-Onge’s team previously reported that shortening sleep by 80 minutes for six weeks heavily spiked insulin resistance (a direct precursor to type 2 diabetes), with the worst outcomes found in postmenopausal women. Additionally, the mild restriction triggered a measurable influx of inflammatory cells into the heart tissue of adults with elevated cardiac risk.
Source: Columbia University
People who shortened their sleep by around 80 minutes a night for six weeks gained weight—one pound on average—and were more sedentary, researchers at Columbia University Vagelos College of Physicians and Surgeons have found.
“Our study shows that getting adequate sleep may help reduce the risk of weight gain and obesity-related conditions like heart disease and diabetes,” says Marie-Pierre St-Onge, a professor of nutritional medicine in Columbia’s Department of Medicine and Institute for Human Nutrition and study leader. “People tend to gain weight over the course of their adulthood, and obesity is a major risk factor for heart disease. But focusing on eating a healthier diet and getting more physical activity to offset weight gain is simplistic and can be difficult to maintain.”
Studying the effects of chronic, mild sleep deficits
Much of what’s known about the link between insufficient sleep and obesity is based on small, brief studies of people who endured severe sleep restriction (usually 4 hours of sleep opportunity). Such studies show that severe sleep deprivation leads to changes in appetite and overeating, which can contribute to weight gain over time.
But most people cannot tolerate severe sleep deprivation for more than a few days.
“These studies only show us what happens under the most extreme conditions and don’t tell us if mildly sleep-deprived people, like a lot of Americans who get 5 or 6 hours of sleep a night, will gain weight,” St-Onge says.
Six weeks of short sleep = 1 extra pound
To investigate the effects of chronic mild sleep deprivation, a sleep pattern adopted by roughly 30% of adults, St-Onge and her team recruited 95 adults who usually get 7-8 hours of sleep. Participants were instructed to delay their normal bedtime by 90 minutes for one six-week phase and to get the usual amount of sleep for another six-week phase. Sleep and activity levels were measured throughout each phase with a wrist monitor, along with changes in body weight, waist circumference, body composition, and fasting levels of several hormones known to increase or suppress appetite.
“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,” says Faris Zuraikat, assistant professor of nutritional medicine in Columbia’s Department of Medicine and Institute for Human Nutrition and first author of the study. “Our study was designed to mimic sleep patterns that most adults experience chronically. 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.”
Sedentary time also increased by an average of 17 minutes per day during the sleep-restriction phase overall, and by nearly 30 minutes per day for men and postmenopausal women.
“Even when we accounted for the fact that they were awake longer when sleep was shortened, participants spent more time being inactive than when they got adequate sleep,” Zuraikat says. “This is notable, as people who are more sedentary have elevated risk for chronic diseases.”
Why does mild sleep deprivation cause weight gain?
In a previous, related study of a sub-set of the same participants, St-Onge’s team reported that women with increased cardiometabolic risk who shortened their sleep by around 80 minutes a night over six weeks had increased insulin resistance, a risk factor for type 2 diabetes. The effects were more pronounced in postmenopausal women.
In another study of this group, St-Onge found that men and women with elevated heart risk had an influx of inflammatory cells in the heart after mild sleep restriction.
“Though more research is needed to further understand how sleep restriction leads to weight gain, all of our findings suggest that insufficient sleep increases the risk of obesity-related conditions like type 2 diabetes and heart disease,” St-Onge says. “Now we need to understand the health effects of improving sleep in those who fail to get adequate sleep on a regular basis.”
Additional information
The article, titled “Skimping on Sleep and Its Impact on Body Weight and Composition: A Pooled Analysis of Randomized Trials,” was published on July 6 in Annals of Internal Medicine.
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.
Funding: The study was supported by the American Heart Association (16SFRN27950012) and the National Institutes of Health (R01 HL128226, UL1 TR001873, P30 DK026687, R01 HL173190, R01 HL155190, R01 HL153642, K01 HL145023, R01 HL169991, R01 HL106041, R35 HL155670, R01 AG071032, R56 DK136601, P30 DK048520, and R01 DK128154).
Key Questions Answered:
A: While gaining one single pound over six weeks might seem minor, you have to look at the timeline. This weight gain happened over a very brief window from a subtle, minor bedtime shift. Dr. Faris Zuraikat points out that this study was specifically designed to mirror the chronic sleep habits of millions of regular adults. When you extrapolate that one-pound six-week trajectory across a full year, losing less than an hour and a half of sleep per night can easily compound into substantial, clinically meaningful weight gain that severely stresses your metabolism.
A: You might assume that being awake for an extra 90 minutes a night would naturally lead to more moving around and burning calories. However, the study unmasked an inactivity paradox: when sleep is shortened, the body pushes back by increasing sedentary time by 17 minutes overall, and by nearly 30 minutes for men and postmenopausal women. Mild sleep deprivation inflicts a subtle, systemic fatigue that drains your spontaneous energy, leaving you significantly more inactive throughout the day regardless of how long you are awake.
A: Sleep is not just passive downtime; it is an active period where your brain regulates hormones, balances blood sugar, and clears out cellular stress. When you skimp on sleep by 80 minutes a night, you disrupt this internal maintenance cycle. Columbia’s related tracking showed that this mild restriction caused women, especially postmenopausal women, to experience a sharp rise in insulin resistance, which is a direct stepping stone to type 2 diabetes. Furthermore, in patients with elevated heart risk, it triggered a direct influx of inflammatory cells into the heart tissue, proving that minor sleep deficits deal a direct blow to cardiovascular health.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- Journal paper reviewed in full.
- Additional context added by our staff.
About this sleep and weight gain research news
Author: Helen Garey
Source: Columbia University
Contact: Helen Garey – Columbia University
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Skimping on Sleep and Its Impact on Body Weight and Composition: A Pooled Analysis of Randomized Trials” by Bin Cheng, Brooke Aggarwal, Edward L. Melanson, Faris M. Zuraikat, Justin A. Cochran, Keith M. Diaz, Marie-Pierre St-Onge, Samantha E. Scaccia, Sanja Jelic, Seth A. Creasy, Wei Shen. 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 associated with obesity. However, the causal effect on weight status of chronic, mildly insufficient sleep and its potential variability by gender and menopausal status remain unknown.
Objective:
To explore the effect of 6 weeks of sleep restriction (SR) of 1.5 hours per night on energy balance and body weight regulation.
Design:
Pooled analysis of 2 randomized crossover trials. (ClinicalTrials.gov: NCT02960776 and NCT02835261)
Setting:
Outpatient intervention with inpatient and outpatient assessments.
Participants:
Adults (n = 95) aged 20 years or older at elevated cardiometabolic risk with habitual sleep of 7 or more hours per night.
Intervention:
Six weeks of sustained adequate sleep (AS) and SR of 1.5 hours per night separated by a multiweek washout.
Measurements:
Outcome measures included adiposity (assessed using magnetic resonance imaging), body weight, waist circumference, and energy balance behaviors and biomarkers.
Results:
Sleep duration was reduced by 78.4 minutes (95% CI, −83.5 to −73.3 minutes) per night with SR versus AS. Body weight (0.45 kg [CI, 0.33 to 0.57 kg]), waist circumference (0.52 cm [CI, 0.25 to 0.79 cm]), and whole-body volume (0.56 L [CI, 0.19 to 0.93 L]) were increased with SR relative to AS. Leptin levels were elevated with SR versus AS (2.03 ng/mL [CI, 0.38 to 3.68 ng/mL]). Sedentary time was increased by 17.2 minutes (CI, 11.7 to 22.7 minutes) per day with SR versus AS.
Limitations:
The intervention duration may have been too short to identify changes in body composition, power to evaluate individual differences was limited, and effect sizes were modest.
Conclusion:
Prolonged exposure to moderately short sleep may lead to weight gain, suggesting that weight management and cardiometabolic disease prevention programs should consider incorporating sleep strategies to promote AS.
Primary Funding Source:
National Institutes of Health and American Heart Association.
