Columbia Study Links Just 90 Minutes Less Sleep to Weight Gain and Health Risks
A recent study from Columbia University reveals that reducing nightly sleep by just 90 minutes over six weeks can lead to weight gain and negatively impact lifestyle habits. Nearly 100 adults who typically slept seven to eight hours were asked to delay their bedtime by 90 minutes each night without changing their daily routines. Despite being awake longer, participants did not increase physical activity; instead, they spent an average of 17 more minutes daily sitting or inactive. Among men and postmenopausal women, groups already at higher risk for weight gain, sedentary time increased by nearly 30 minutes per day.
Dr. Paris Zourakiet from Columbia's Department of Medicine noted that even with extended waking hours, participants remained largely inactive. By the end of the six weeks, average weight increased by about half a kilogram. Researchers warn that while this gain is moderate, prolonged sleep reduction over months or years could lead to significant weight gain and heightened obesity risk. The study also tracked sleep and activity patterns via smartwatches and measured weight, waist circumference, body composition, and hunger-related hormone levels.
This research aligns with previous findings showing chronic sleep deprivation raises insulin resistance, a key risk factor for type 2 diabetes, increases inflammation, and may elevate cardiovascular disease risk. Professor Marie-Pierre Saint-Onge, a study contributor, emphasized that insufficient sleep raises the risk of obesity-related conditions including diabetes and heart disease. The mechanism involves increased ghrelin, the hunger hormone, which boosts cravings for calorie-dense foods, while fatigue reduces daytime activity and energy expenditure.
Health guidelines recommend seven to nine hours of sleep per night, yet about one-third of adults fail to meet this. Beyond weight gain, chronic sleep deprivation is linked to higher accident risk, impaired concentration, slower reaction times, and greater chronic disease susceptibility. The researchers conclude that adequate sleep is essential not only for alertness and mood but also for maintaining healthy weight and metabolic and cardiovascular health over time.
