Food sensory preferences and aversions and therefore the selective intake of nutrients are conditioned by the post-ingestive nutritive or deleterious effects of foods. Like the selective response to carbohydrates is permitted by a common sweet taste, it could be suspected that a common fatty odor or a common greasy texture could represent a “fat flavor” allowing the selective intake of fats. The method of “illness-induced-aversion” was used on groups of normal and anosmic rats. Rats were offered stock powdered diet mixed with 20% of a fat (Butter B, Margarine M, Vaseline V, Lard L) on the conditioning day and the same or different fat on the test day. Results obtained in normal rats indicated that the conditioned aversion against L, B and M was generalized from one to the others but it was not generalized to V. Results in anosmic compared to intact rats displayed that a proximity of the greasy texture of L, B and M and of the odor of B, M, V explains the various levels of generalization observed in intact rats. However the existence of a family of fatty odors was not confirmed by the results.