dl-fenfluramine challenge to nutrient-specific textural preference conditioned by concurrent presentation of two diets.

Effects of the ingestion of protein and carbohydrate conditioned a preference for one size of chow particle over another, which was triggered by need for a specific nutrient. This learned elicitation of nutrient-specific dietary selection was not changed by injection of dl-fenfluramine HCl (2.5 mg/kg). This indicates that previously observed effects of fenfluramine on differential intakes of dextrin- and casein-rich diets do not depend on nutrient-specific self-selection.