Eating Decisions Based on Alertness Levels after a Single Night of Sleep Manipulation: A Randomized Clinical Trial.

STUDY OBJECTIVES: To determine the relationship between an ecologically-relevant change in sleep behavior and its subsequent effects on daytime alertness and feeding behavior.

METHODS: Fifty healthy, young participants (10 male, 40 female) completed two 3-hour study sessions that were at least five days apart. The first session was a baseline evaluation. On the night prior to Session 2, the amount of time in bed was manipulated to be 60-130% of the individual's habitual sleep time. Within both sessions, subjective (Stanford Sleepiness Scale) and objective (Psychomotor Vigilance Test) alertness were measured. During the middle of each session, a 40-minute ad libitum meal opportunity allowed participants to eat from eight different food items. Food healthfulness, caloric density, distribution and number of calories were measured and compared to alertness levels.

RESULTS: The induced variation in time in bed resulted in induced variation in both subjective and objective (p<0.05) measures of alertness. Decreased subjective alertness was associated with increased total caloric consumption (p<0.05), and a greater number of calories consumed from less healthy food (p<0.05), as rated by both the investigators and by the participant. Decreased objective alertness was associated with less healthy food choices (p<0.05), and the consumption of more food from the calorically-dense items (p<0.05).

CONCLUSIONS: Ecologically-relevant impairments in subjective and objective alertness are associated with increased caloric intake and dysfunctional eating decisions. People experiencing reduced alertness after modest sleep loss may be more willing to eat food they recognize as less healthful, and appear to prefer more calorically dense foods.