Abstract Introduction The foods you choose at night may make or break your sleep. Prior research reveals a relationship between diet and sleep, where dietary composition affects sleep quality. High intake of saturated fat and simple carbohydrates, in combination with late-night or irregular eating patterns, has been linked to impaired sleep architecture and circadian disruption. We hypothesized that greater calories and grams of sugar, and carbohydrates consumed from the last meal would reduce sleep efficiency, with caloric intake showing a non-linear effect. Methods 28 adolescents completed a one-week protocol assessing links between dietary intake and sleep. Sleep efficiency was measured with actigraphy watches, and dietary intake was collected using the Automated Self-Administered 24-Hour Dietary Assessment Tool (ASA-24). Multiple recalls per participant provided 94 dietary data points, which matched 65 next-night sleep actigraphy data. We ran separate regressions examining how kilocalories, carbohydrates, and sugar intake before bedtime predicted sleep efficiency. Second, a quadratic regression tested the non-linear relationship between kcal and sleep efficiency. Results Kilocalories, fat, protein, sugar, and carbohydrates consumed before bed significantly predicted sleep efficiency (F(5,59)=2.90, p=0.0207), accounting for 20% of its variance (R²=.20). Kilocalories alone did not significantly predict sleep efficiency (b=-0.73, p=0.51). However, sugar consumption significantly predicted sleep efficiency (F(1,63)=10.51, p=0.002), with higher sugar linked to poorer sleep efficiency (b=-.07, 95%CI-.12, -.03). Carbohydrate consumption also significantly predicted sleep efficiency (F(1,63)=4.30, p=0.04), with higher intake reducing efficiency (b=-.03, 95%CI-.06, -.001). A third regression with a quadratic term (F(6,58)=2.45, p=0.0355, R²=.20) indicated that neither the linear (b=-0.77, p=0.498) nor quadratic term was significant (b=0.00, p=0.576). Conclusion Altogether, our analyses showed that it is not the total amount of energy consumed before bed, but rather the composition of that intake that shapes adolescent sleep efficiency. Kilocalories did not uniquely predict sleep efficiency when other macronutrients were considered; however, higher sugar and carbohydrate consumption independently predicted poorer sleep efficiency. These findings point to metabolic and glycemic-related pathways as more salient for sleep disruption than overall caloric intake. Future sleep promotion interventions may benefit from targeting nutritional quality, including limiting simple sugars and refined carbohydrates before bed. Support (if any)
d'Hulst et al. (Fri,) studied this question.