Chronic, mild sleep restriction—cutting sleep by just 80 to 90 minutes per night—can lead to measurable weight gain and increased sedentary behavior, according to research published in the Annals of Internal Medicine. A study led by researchers at the Columbia University Vagelos College of Physicians and Surgeons found that adults who reduced their sleep for six weeks gained an average of one pound and increased their daily inactivity.
Impact of Mild Sleep Restriction on Body Weight
While much of the scientific literature on sleep has historically focused on extreme sleep deprivation—such as limiting participants to four hours of sleep—the Columbia University team sought to replicate the patterns of the roughly 30% of adults who chronically get insufficient sleep.
In a study involving 95 adults who typically slept seven to eight hours nightly, researchers observed participants over two six-week periods. In one phase, participants delayed their bedtime by 90 minutes; in the other, they maintained their regular schedule. By the end of the sleep-restricted phase, participants had gained an average of one pound.
Sleep Loss and Sedentary Behavior
Beyond weight gain, researchers identified a significant shift in physical activity levels. During the weeks of restricted sleep, participants spent an average of 17 additional minutes per day being sedentary. This effect was more pronounced among men and postmenopausal women, who recorded nearly 30 minutes of additional inactivity daily.
Faris Zuraikat, the study’s first author and an assistant professor of nutritional medicine, noted that this increase in sedentary time occurred even when accounting for the extra hours participants were awake. Because sedentary behavior is an established risk factor for chronic conditions, this finding highlights a potential behavioral mechanism by which poor sleep exacerbates health risks.
Connection to Obesity-Related Conditions
The findings published in the Annals of Internal Medicine build upon a body of research linking sleep quality to cardiometabolic health. In related investigations by the same team, participants with elevated heart disease risk showed an influx of inflammatory cells in the heart after periods of mild sleep restriction. Additionally, women with increased cardiometabolic risk demonstrated higher levels of insulin resistance—a precursor to type 2 diabetes—after reducing their sleep by 80 minutes nightly for six weeks.
The study, "Skimping on Sleep and Its Impact on Body Weight and Composition: A Pooled Analysis of Randomized Trials," suggests that addressing sleep duration may be a vital component in preventing obesity-related diseases, independent of traditional diet and exercise interventions.
Key Findings at a Glance
- Study Duration: Participants were monitored over two six-week phases.
- Weight Gain: A consistent reduction of roughly 80–90 minutes of sleep led to an average weight gain of one pound.
- Inactivity: Sedentary time increased by an average of 17 minutes daily, with higher increases in men and postmenopausal women.
- Metabolic Risks: Sleep restriction is linked to increased insulin resistance and inflammatory responses, both of which are associated with heart disease and type 2 diabetes.
The research was supported by funding from the American Heart Association and the National Institutes of Health. The study authors reported no conflicts of interest.