Biological sex and glucoregulation modulate postprandial cognition following dairy milk and fruit juice in healthy school-age children.

Objectives: Recent work suggests potential postprandial benefits for cognition and on-task behavior in children, depending on the macronutrients consumed, as well as individual differences such as sex and glucoregulation. We examined the effects of 1% milk versus apple juice on cognition and on-task behavior among healthy school-age children, predicting that milk would promote better performance and a greater presence of on-task behavior compared to juice. We also examined how sex and glucoregulation influenced cognition and behavior following each beverage.Methods: Eighty-four English-speaking children ages 8-12 (45 female, 39 male) attended two 0800 testing sessions after fasting overnight in a crossover design. Participant sessions were counterbalanced to include 237 mL of 1% milk or apple juice. Behavioral measures and complex attentional and executive function tasks were assessed at baseline, 30, 90, and 120 min post-ingestion. Outcomes were analyzed using repeated measures mixed models.Results: Participants with fasting glucose levels above 89.91 mg/dL responded more quickly in an inhibitory control paradigm following milk. Females performed faster on a vigilance task, but less accurately in a working memory paradigm after milk versus juice. No effects were found for on-task behavior.Discussion: Results demonstrated modulatory effects of glucoregulation and sex on postprandial cognition. Milk may improve cognitive performance in school-aged children with higher fasting glucose, and may be the optimal choice for speed among females, whereas juice may be better for accuracy. Future work should utilize designs incorporating glucoregulation and sex, and consider additional biological variables to better understand postprandial cognition and behavior in children.