Comparison of the effects of high-carbohydrate and low-carbohydrate meals on drowsiness and biological indices

Abstract

The contents of a meal may affect postprandial performance, e.g., by causing drowsiness. Therefore, we investigated the effects of a low-carbohydrate meal (LCM) on drowsiness and performance. We evaluated postprandial drowsiness, wakefulness, and concentration level by eye tracking analysis, monitored blood glucose levels over time, and measured autonomic nervous system activity and cognitive function before and after the meal. In addition, participants subjectively evaluated their condition with a visual analogue scale. We found that the postprandial rise in blood glucose level was significantly lower after an LCM than after a high-carbohydrate meal (HCM), but the results of the eye tracking test showed no statistically significant differences between the LCM and HCM. However, it tended to decrease blink duration and increase pupil diameter and fixed gaze duration after the LCM compared to HCM. The findings suggest that postprandial blood glucose levels and the eye tracking indices were possibly related.