# Even Mild Sleep Deprivation May Lead to Weight Gain Columbia University study reveals chronic sleep deficiency can cause measurable weight increase. - **Source:** [Science Latest](https://brifing.si/source/ebc20f22-8d1a-4ae4-ba4c-efcd0853ba19) - **Published:** 2026-07-20 - **Original article:** - **On Brifing:** https://brifing.si/s/d993d3ec-196b-4289-abc2-0ebcd619cd94 ## Sleep-Weight Connection While severe sleep deprivation's link to weight gain was known, new Columbia research shows even 80 minutes less sleep daily can lead to increased weight. This highlights how chronic sleep deficiency - affecting 30% of adults - poses significant health risks, challenging common perceptions about 'mild' sleep loss. ## Study Methodology Researchers tracked 95 adults normally sleeping 7+ hours, delaying their bedtime by 90 minutes for 6 weeks. Monitoring revealed an average 0.45kg (1lb) weight gain during sleep restriction. Projected annually, this suggests substantial weight accumulation from chronic mild sleep deprivation, with implications for obesity prevention strategies. ## Reduced Physical Activity Surprisingly, participants sat 17 minutes more daily during sleep restriction - increasing to 30 minutes for men/postmenopausal women. This indicates sleep loss doesn't just extend wakefulness but actually decreases movement. The sedentary behavior compounds metabolic risks beyond simple calorie calculations from extra awake time. ## Unexpected Hormonal Changes Contrary to severe sleep deprivation studies, appetite-suppressing leptin levels increased during mild sleep restriction. This challenges existing 'hormonal disruption-overeating' theories, suggesting mild sleep loss affects weight through different mechanisms. Researchers speculate energy expenditure changes may play greater role than appetite hormones here. ## Broader Health Impacts Prior studies with these participants showed sleep reduction increased insulin resistance (diabetes risk) and made immune cells more inflammatory. These multidimensional effects demonstrate how chronic mild sleep deficiency simultaneously impacts metabolic, cardiovascular and immune systems - making it a multifaceted public health concern. ## Modern Lifestyle Warning The research proves accumulated minor sleep deficits create measurable health risks, questioning sleep-deprioritizing modern lifestyles. Next steps involve quantifying health benefits from sleep extension. As obesity-related diseases rise globally, these findings position sleep hygiene as a modifiable risk factor in preventive healthcare strategies. ## Sources covering this story - https://www.wired.com/story/even-mild-sleep-deprivation-may-lead-to-weight-gain/ — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._