Insufficient sleep undermines dietary efforts to reduce adiposity
Abstract
Background
Sleep loss can modify energy intake and expenditure.
Objective
To determine whether sleep restriction attenuates the effect of reduced-calorie diet on excess adiposity.
Design
Randomized two-period two-condition crossover study.
Setting
University clinical research center and sleep laboratory.
Patients
10 overweight nonsmoking adults (3F/7M); mean (SD) age 41 (5) y; body mass index 27.4 (2.0) kg/m2.
Intervention
14 days of moderate caloric restriction with 8.5 or 5.5-hour nighttime sleep opportunity.
Measurements
Primary: loss of fat and fat-free body mass. Secondary: changes in substrate utilization, energy expenditure, hunger, and 24-h metabolic hormone concentrations.
Results
Sleep curtailment decreased the fraction of weight lost as fat by 55% (1.4 vs. 0.6 kg with 8.5 vs. 5.5-h sleep opportunity, P=0.043) and increased the loss of fat-free body mass by 60% (1.5 vs. 2.4 kg, P=0.002). This was accompanied by markers of enhanced neuroendocrine adaptation to caloric restriction, increased hunger, and a shift in relative substrate utilization towards oxidation of less fat.
Limitations
The nature of the study limited its duration and sample size.
Conclusions
The amount of human sleep contributes to the maintenance of fat-free body mass at times of decreased energy intake. Lack of sufficient sleep may compromise the efficacy of typical dietary interventions for weight loss and related metabolic risk reduction.
