Abstract Body: Introduction: Chronic sleep deprivation and circadian misalignment are associated with cardiometabolic dysfunction, but few have studied the effects of nocturnal wakefulness-induced cognitive deficits on food decision making, and whether this exacerbates obesity risk.
Hypotheses: In line with previous work, we hypothesized that short sleep would lead to greater next-day caloric intake, and nocturnal wakefulness would be associated with greater impulsive eating.
Methods: Young, healthy adults (18-25 years; n = 17; 9 female) participated in a three-week protocol in which they tracked their habitual sleep and food intake from home during weekdays and spent two consecutive weekends in the lab. During lab visits, participants completed serial neurocognitive assessments, ate ad libitum, and experienced partial sleep restriction (on Weekend 1 with an advanced wake time and on Weekend 2 with a delayed bedtime).
Results: A principal component analysis (PCA) was used to model eating behavior throughout both in-lab weekends. Energy intake (total calories) was significantly correlated with the PCA in both the advanced wake (R = 0.996; p < 0.0001) and delayed sleep (R = 0.998; p<0.0001) conditions. Thus, energy intake was shown to increase over time when partial sleep restriction occurred, regardless of nocturnal wakefulness timing. The Three Factor Eating Questionnaire Cognitive Restraint subdomain score was significantly correlated with caloric intake for both the advanced wake (R = 0.603; p = 0.01) and delayed sleep (R = 0.554; p = 0.02) conditions. Thus, lower self-reported cognitive restraint was associated with higher caloric intake. Normalized Monetary Choice Questionnaire score (an instrument used to measure delayed discounting/impulsivity) was significantly associated with caloric intake in the advanced wake (R = 0.604; p = 0.01), but not the delayed sleep (R = 0.0367; p = 0.15) condition. Pittsburgh Sleep Quality Index score was not associated with caloric intake in either condition.
Conclusions: An advanced wake time may increase the risk of obesity among young adults who exhibit greater impulsivity, though any circadian perturbations may promote greater next-day caloric intake. Impaired dietary decision-making due to circadian misalignment and sleep loss may be a previously underappreciated public health concern, with implications for early morning shiftwork schedules and college start times.