Early Sleep Midpoints are Associated with Increased Fruit, Water, and Fiber Intakes and Decreased Discretionary Calories in a Young Adult Cohort

Abstract

Previous research suggests a link between poor sleep quality and increased consumption of energy dense foods. However, little is known about the timing [midpoint] of sleep and whether or not it affects dietary intake. The purpose of this study was to determine if early, middle, or late sleep midpoints were associated with healthier diets among students participating in the ongoing College Health and Nutrition Assessment Survey at the University of New Hampshire between 2012‐14 [n= 1,302; 69.6% female; mean age=19 years]. Sleep behaviors were collected from an online questionnaire and dietary intakes were assessed using three‐day food records and nutrient analysis software (Diet Analysis Plus). Sleep midpoints were calculated from self‐reported bed times and rise times on usual weekdays and subsequently divided into tertiles. On average, students reported 8.14 hours of sleep and had a sleep midpoint time of 3:54 am. As compared to those in the latest sleep midpoint tertile, students in the earliest tertile had higher intakes of fruit (1.5±.1 vs. 1.3±.1 cups, p<0.05), fiber (23.1±.4 vs. 19.8±.4 grams, p<0.05), total water (2.1±.1 vs. 1.8±.1 L, p<0.05), and a lower ratio of discretionary calories to total calories (28.9±.5 vs. 30.8±.5%, p<0.05). No differences were seen in total fat or carbohydrate intake between tertiles. Findings from this project suggest college students with earlier sleep midpoints consume healthier diets, including more fruit and less discretionary calories.