Daytime sleepiness affects prefrontal regulation of food intake

► Functional magnetic resonance imaging data were acquired in healthy men and women. ► During imaging, participants viewed images of high- and low-calorie foods. ► Sleepiness correlated negatively with ventromedial prefrontal cortex activity. ► Prefrontal cluster activation predicted the tendency to overeat during meals. ► Sleepiness may contribute to overeating by reducing prefrontal brain functioning.