Sleep Deprivation Linked to Weight Gain, Study Finds

Adults who delayed bedtime by 60 minutes nightly for six weeks, while maintaining the same wake time, gained an average of 1 pound, according to Marie-Pierre St-Onge, PhD, a professor of nutritional medicine at Columbia University Irving Medical Center.

How Does Sleep Deprivation Affect Weight Gain?

The study tracked 95 adults with elevated cardiometabolic risk, who averaged 7.5 hours of sleep per night before the trial. During the six-week shortened-sleep phase, participants slept 78 minutes less nightly on average, resulting in a 0.45 kg (1 pound) weight gain.

“Sleep is so underestimated in our society,” said Yuval Pinto, MD, an obesity and family medicine doctor at Johns Hopkins Medicine. “It’s the second most important aspect when it comes to weight loss after nutrition.”

What Are the Hormonal Impacts of Poor Sleep?

Participants showed higher leptin levels, a hormone associated with energy storage, during the shortened-sleep phase. While ghrelin (a hunger hormone) and GLP-1 (linked to fullness) remained stable, researchers noted that fasting hormone levels may not capture daily fluctuations. St-Onge’s prior research found that sleep restriction can increase food intake, contributing to weight gain.

How Does Sleep Loss Affect Metabolism?

Previous trials by St-Onge’s team found that cutting sleep by 80 minutes nightly for six weeks reduced insulin sensitivity in women. This means the body requires more insulin to regulate blood sugar, increasing prediabetes and type 2 diabetes risk over time.

What Are the Limitations of This Study?

The study’s short duration (six weeks) and small sample size (95 adults) limit broader applicability. Participants also had elevated cardiometabolic risk, so results may not reflect the general population.

What Are the Signs of Insufficient Sleep?

St-Onge identifies key indicators of sleep deprivation: yawning, difficulty staying alert, dozing during quiet activities, mood changes, unrefreshing wake-ups, and trouble concentrating. “If you’re sleeping longer when given the chance, that’s a red flag,” she said.

How Can You Improve Sleep Quality?

Pinto recommends:

• Going to bed only when tired
• Maintaining a cool, dark sleep environment
• Avoiding food 2–3 hours before bedtime
• Screening for sleep disorders like apnea

“Untreated sleep issues can sabotage weight loss efforts,” Pinto said. “If you wake up sweaty or experience daytime sleepiness, consult a healthcare provider.”

Why Does Sleep Matter for Weight Management?

Chronic sleep deprivation disrupts energy balance by increasing sedentary behavior and altering hunger hormones.