Hedonic and sensory expectations related to fat-free and regular-fat pound cake, crackers and American cheese were studied with 97 subjects divided into three subgroups, each testing one type of product. Four study phases were separated by 1-month intervals: (1) a questionnaire on demographics, dietary practices and consumption of the test products, (2) intensity ratings of sensory attributes and ratings of liking of unlabeled fat-free and regular-fat samples, (3) ratings of expected attribute intensities and liking in response to product labels of "fat-free" and "regular", and subsequent ratings of these samples and (4) phase 3 repeated with opposite (incorrect) labels. Fat-free products were expected to be less liked than their regular counterparts; however, only cheese was less liked in actual taste tests. Expected liking was best predicted by familiarity with the product and, in the case of fat-free products, by the extent to which a person substituted low-fat for high-fat foods. Actual liking was best predicted by the effect of labeling and by expectations. The expected intensities of sensory attributes were uniformly higher in regular than in fat-free products. Both sensory and hedonic ratings of labeled samples changed in the direction of expectations, as compared to baseline values, supporting an assimilation model of the effect of disconfirmed expectations on sensory perception and consumer acceptance.