Effects of Diurnal Intermittent Fasting on Daytime Sleepiness Reflected by EEG Absolute Power

Purpose: We hypothesized that diurnal intermittent fasting would not increase slow frequency EEG waves, which reflect increased sleepiness. Therefore, this study aimed at performing a quantitative EEG analysis of young healthy volunteers with and without diurnal intermittent fasting while controlling for potential confounders. Methods: Eight young healthy volunteers (mean age: 24.4 ± 3.7 years) reported to the laboratory during the following five occasions: (1) adaptation, (2) 4 weeks before Ramadan while performing diurnal intermittent fasting (fasting from dawn to sunset) for 1 week (fasting outside Ramadan), (3) 1 week before Ramadan (nonfasting baseline), (4) during the second week of Ramadan while fasting (Ramadan), and (5) 2 weeks after Ramadan (recovery). Frontal, central, and occipital EEG signals were monitored four times (09:15, 11:15, 13:15, and 15:15 for 15 minutes each time) while the participants were awake to assess EEG spectral power of the delta, theta, alpha, and beta frequency bands. Results: During wakefulness, no difference in EEG slowing was observed between nonfasting baseline and fasting during and outside Ramadan. There were no differences in the mean absolute power of each band in any studied brain region in any of the four study periods. Moreover, there was no difference in EEG absolute powers in the delta, theta, alpha, and beta frequency bands for any individual brain region during the four study periods. Conclusions: Spectral analysis of EEG power indicates that diurnal intermittent fasting does not increase sleepiness. Future larger studies are needed to confirm the current findings.