Twenty-four types of well-known biscuits and cakes were sampled to represent as much as possible the wide range of products available on the French market and their variations in fat and sugar contents. First, 62 consumers recorded their liking while tasting the products in laboratory conditions. Then, they judged the sweetness and fattiness of the products in two manners: (1) using a home-based questionnaire showing product pictures (expected intensities), (2) after tasting the products in laboratory conditions (perceived intensities). To compare nutritional contents with intensity scores, Pearson correlations were calculated. Furthermore, expected and perceived intensities were linearly transformed into relative fat and sugar contents. Gaps between nutritional, expected and perceived data were examined. For both fat and sweetness, expected and perceived intensities were strongly correlated (r=0.95 and 0.93, respectively) meaning that people either know the taste of most products by experience or base their sensory perception on beliefs about the products. Additionally, for both fat and sweetness, actual contents were highly correlated with expected intensities (r=0.72 and 0.69) and perceived intensities (r=0.77 and 0.73). Consumers appear to be relatively good at estimating fat and sugar contents in biscuits; product tasting improves these estimations by only a small extent. Correlations between liking and actual, expected and perceived data were equal to 0.47, 0.48 and 0.57 for fat and 0.34, 0.45 and 0.53 for sweetness. These increasing figures suggest that people mainly like biscuits perceived as fat and sweet or, to a smaller degree, expected as such. Moreover, the analysis of gaps between nutritional, expected and perceived data for each product showed that there were significant differences between products (figure 1), probably due to sensory dissimilarities. Overall, this study is a clear justification for trying to keep the fatty and sweet sensations as high as possible in new low-fat, low-sugar food products.