Chronic Mild Sleep Restriction Linked to Weight Gain in Adults

The study revealed that while sleep restriction resulted in more sedentary behavior, it did not change the amount of time spent in moderate-to-vigorous physical activity (MVPA) or total daily energy expenditure. Evidence from the research rates level one, indicating excellent quality.

Most previous studies on sleep and obesity focused on severe sleep deprivation (4-5 hours per night) over short periods, typically lasting two weeks. However, this research explores chronic mild sleep restriction, defined as approximately 6 hours per night, to understand its effects on weight regulation in adults. Participants underwent two 6-week intervention periods in a randomized crossover format: one with a nightly bedtime delay of 1.5 hours leading to chronic sleep restriction, and another where they maintained at least 7 hours of sleep.

Findings showed that, in comparison to adequate sleep, chronic sleep restriction correlated with an average weight gain of 0.45 kg, an increase in waist circumference of 0.52 cm, and a rise in whole-body volume of 0.56 L. Despite increased sedentary time during the restricted sleep phase, participants did not alter their engagement in MVPA or total daily energy expenditure.

The study had several limitations, including a small sample size and a short intervention duration, which restrict the generalizability of the results. A total of 95 adults aged 20 or older participated, with 72 women (including 15 postmenopausal) involved in the trials. Both trials excluded individuals with various health issues or factors that could influence sleep or metabolism. Following a 2-week screening period, participants who typically slept at least 7 hours on 70% of nights were eligible.

Overall, the study highlights that even mild chronic sleep restrictions can contribute to weight gain and adverse body composition changes, underscoring the importance of sufficient sleep in weight management and the prevention of cardiometabolic diseases.