Effects of Experimental Sleep Restriction on Energy Intake, Energy Expenditure, and Visceral Obesity.
Level 2 - randomized trial
Randomized controlled crossover trial in humans
PubMed 35361348 · doi:10.1016/j.jacc.2022.01.038
What was done
Twelve healthy, nonobese individuals (9 males, age range 19 to 39 years) completed a randomized, controlled, crossover, 21-day inpatient study with ad libitum food access. The protocol comprised 4 days of acclimation, 14 days of either experimental sleep restriction (4-hour sleep opportunity) or control sleep (9-hour sleep opportunity), and a 3-day recovery segment. Researchers measured energy intake, energy expenditure, body weight, body composition, fat distribution, and circulating biomarkers.
What was found
Compared to control sleep, sleep restriction significantly increased caloric intake (P = 0.015), with increased protein (P = 0.050) and fat intake (P = 0.046). Energy expenditure did not change (all P > 0.16). Participants gained significantly more weight during sleep restriction (P = 0.008). While total body fat changes did not differ between conditions (P = 0.710), total abdominal fat increased only during sleep restriction (P = 0.011), with significant increases in both subcutaneous abdominal fat (P = 0.047) and visceral abdominal fat (P = 0.042). Absolute numerical changes and effect sizes were not provided in the abstract.
Why it matters
This study provides direct experimental evidence that sleep restriction promotes excess caloric intake and specifically increases visceral abdominal fat accumulation.
Limits
The sample size was very small (n = 12) and predominantly male (9 of 12). The inpatient setting with extreme restriction (4 hours) may not fully reflect free-living conditions, and the abstract omits exact numerical values for calories consumed and fat gained.
Cited by
- supports Restricting sleep to about 5 hours per night for two weeks causes individuals to gain approximately half a kilogram (one pound) of weight.