Hunger/craving responses and reactivity to food stimuli during fasting and dieting.

One group of fasting obese patients and one group of dieting obese patients were instructed to report their feelings of hunger and craving on a continuous basis before and during a three-week treatment period. Once a week they were also exposed to food slides to measure their reactivity to food stimuli. The frequency of hunger/craving responses and reactivity to food stimuli showed radically different changes over time in the fasting and dieting groups. During the last week of fasting, reactivity to food slides was completely abolished, and the frequency of hunger/craving responses was close to zero. Only slight changes of frequency of hunger/craving responses and reactivity to food stimuli were observed in the dieting group. The results suggest that the frequency of hunger/craving responses and reactivity to food stimuli show parallel decreases during fasting, but no changes during dieting.