The nature and mechanisms of altered food acceptability during adherence to a reduced-fat diet have not been characterized. These issues were assessed in healthy adults assigned to a reduced-fat diet excluding discretionary fat sources (n = 9), a similar diet permitting fat-modified products (n = 9) or no dietary modification (n = 9). Sensory responses to foods, body composition, and dietary intake were determined at baseline, monthly during 12 wk of diet adherence, and 12 followup wk. Marked and comparable reductions of fat intake were achieved in the experimental groups. Hedonic (ie, pleasantness) ratings for high-fat foods and preferred fat content of selected foods declined, but only in the group deprived of sensory exposure to fats. Thus, the frequency of sensory exposure to fats exerts a stronger influence on hedonic ratings of foods containing fat than total fat intake. The hedonic shift may promote long-term compliance with a reduced-fat diet.