Chocolate craving and hunger state: implications for the acquisition and expression of appetite and food choice.

The importance of hunger state for the acquisition and expression of chocolate craving was investigated. Seventeen chocolate cravers and 12 non-cravers were supplied with chocolate and instructed to eat some twice a day for 14 days. Within each group, subjects were allocated to one of two conditions, hungry- or full-trained. Hungry-trained subjects were asked to eat the chocolate exclusively at least 2 h after last eating; full-trained subjects were asked only to eat the chocolate 15-30 min after eating a meal. A diary was kept to encourage and allow assessment of compliance. At the start and end of the 2 weeks, subjects rated their craving for and anticipated intake of chocolate prior to eating it; then, on initial tasting, pleasantness of the taste was rated. All subjects made these ratings on one day when hungry and on another when full, as defined above. For cravers and non-cravers who ate chocolate exclusively when hungry, chocolate craving increased post-training, but, at least for cravers, only when ratings were made while hungry. For full-trained subjects, chocolate craving decreased post-training, but this decrease did not depend on whether subjects were currently hungry or full. A similar pattern of results was found for anticipated intake and pleasantness of taste, except that pleasantness did not increase in hungry-trained subjects. The results are interpreted with reference to learned control of appetite and in particular to recent findings on incentive learning processes. Craving for chocolate or other foods may be an expression of a strong appetite elicited by hunger that has been acquired by repeated experience of eating the craved food when hungry.