Study objectives: To investigate the relation between sleep duration and energy consumption in an adolescent cohort.
Setting: Free-living environment.
Participants: Two hundred forty adolescents (mean age 17.7 +/- 0.4 years).
Measurements and results: Daily 24-hour food-recall questionnaires and wrist-actigraphy measurements of sleep duration were employed to test the hypothesis that shorter weekday sleep duration (< 8 h) is associated with altered nutrient intake. Nutrition parameters included total calories, calories from meals and snacks, and proportions of caloric intake from fat and carbohydrates. Compared with adolescents sleeping 8 or more hours on average on weekdays, those sleeping less than 8 hours consumed a higher proportion of calories from fats (35.9% +/- 6.7% vs 33.2% +/- 6.9%; mean +/- SD; P = 0.004) and a lower proportion of calories from carbohydrates (49.6% +/- 8.2% vs 53.3% +/- 8.3%; P = 0.001). After adjusting for potential confounders, shorter sleep duration was significantly associated with an average daily increase of calories consumed from fat of 2.2 percentage points and an average daily decrease in percentage of calories from carbohydrates of 3.0 percentage points. In unadjusted analyses, shorter sleep duration was also associated with a 2.1-fold increased odds (95% confidence interval: 1.03, 4.44) of daily consuming 475 or more kcal from snacks.
Conclusion: Quantitative measures of macronutrient intake in adolescents were associated with objectively measured sleep duration. Short sleep duration may increase obesity risk by causing small changes in eating patterns that cumulatively alter energy balance.