Food Deprivation Sensitizes Pain Perception

While food deprivation has known effects on sympathovagal balance, little is known about hunger’s influence on the perception of pain. Since autonomic activities influence many cognitive and emotional processes, this suggests that food deprivation should interact with the perception of pain. This study analyzed the possible effects of short-term food deprivation on pain sensitivity in healthy female participants. This study was comprised of 32 healthy female participants who underwent a 48-hr inpatient hospital investigation. Prior to testing, heart rate and heart rate variability were assessed. After a standardized breakfast, day 1 measurements were taken. Food intake was then not allowed again until the following evening for 22 participants (experimental group), while 12 participants were served standard meals (control group). Pain threshold and tolerance were assessed at 10:00 a.m. on both days using a pressure algometer. Additionally pain experience was examined. Food deprivation significantly reduced pain thresholds and tolerance scores in the experimental group. Additionally, the sympathovagal balance changed, characterized by a decrease in parasympathetic activation. Higher vagal withdrawal after food deprivation was associated with higher pain sensitivity in the experimental group. Furthermore, perceived unpleasantness and pain intensity increased for threshold and tolerance stimuli in the experimental group. We conclude that short-term food deprivation sensitized pain perception in healthy females. An imbalance in sympathovagal activation evoked by food deprivation accounted for this effect. Our results might be a pathogenic mechanism for the development of emotional difficulties associated with disturbed eating behavior.