Increased Energy Intake Following Sleep Restriction in Men and Women: A One-Size-Fits-All Conclusion?

Objective: This study assessed the degree of interindividual responses in energy intake (EI) to an imposed sleep restriction versus habitual sleep duration protocol. It also investigated participant (age, sex, ethnicity, and BMI) and study (study site and protocol order) characteristics as potential contributors to the variance in EI responses to sleep restriction between individuals. Methods: Data from two randomized crossover trials were combined. All participants (n=43; age: 31 +/- 7 years, BMI: 23 +/- 2kg/m(2)) were free of medical/sleep conditions, were nonsmokers, reported not performing shift work, and had an average sleep duration of 7 to 9 hours per night. Ad libitum, 24-hour EI was objectively assessed following sleep restriction (3.5-4 hours in bed per night) and habitual sleep (7-9 hours in bed per night) conditions. Results: Large interindividual variations in EI change (DEI) between restricted and habitual sleep conditions were noted (2813 to 1437 kcal/d). Only phase order was associated with Delta EI (beta=-568 kcal/d, 95% confidence interval for beta=-921 to -15 kcal/d; P=0.002); participants randomized to the habitual sleep condition first had greater increases in EI when sleep was restricted (P=0.01). Conclusions: Large interindividual variations in Delta EI following sleep restriction were noted, suggesting that not all participants were negatively impacted by the effects of sleep restriction.