Regularly reducing sleep by approximately 90 minutes per night could lead to an average weight gain of about one pound over a six-week period, according to a study published in the Annals of Internal Medicine. Researchers from Columbia University Irving Medical Center observed 95 adults at risk for heart or metabolic disease, comparing periods of adequate sleep with periods of restricted sleep.
During the six-week sleep-restricted phase, participants gained approximately one pound on average and showed slightly larger waistlines. The study also noted an increase in sedentary behavior among participants, though their levels of moderate and vigorous exercise remained consistent. While weight and waist measurements changed, researchers did not find significant alterations in body fat or muscle mass. The study did not track dietary intake, making the specific drivers of the weight increase unclear.
Dr. Somi Javaid, an OB-GYN and founder of HerMD, who was not involved in the study, commented that sleep is crucial for regulating metabolism. She noted that chronic sleep deprivation can hinder weight regulation, with women experiencing menopause being particularly susceptible due to common sleep disturbances during this life stage. "We are destroying women’s sleep at the exact life stage when their metabolism is [the] least able to absorb the hit, then telling them to eat less and exercise more," Javaid stated.
The American Heart Association now includes sleep as one of its "Life’s Essential 8" metrics for heart health, recommending seven to nine hours of sleep nightly for adults. Javaid emphasized the importance of viewing sleep as a vital sign of health, rather than a mere lifestyle choice.
The study authors acknowledged several limitations, including the six-week duration, which may not have been sufficient to detect long-term changes in body fat. The relatively small sample size also limited comparisons between different participant groups. Additionally, some hormone measurements were taken only in the morning, potentially missing daily fluctuations.