Dietary self-selection and intake of protein and energy is altered by the form of the diets.
The technique of dietary self-selection has been widely used to investigate proposed mechanisms of protein and carbohydrate regulation and to substantiate theories relating nutrients, brain chemistry and behaviour. These experiments have produced conflicting results which might be accounted for by differences in experimental variables or in the different techniques used to measure self-selection. The possibility that the sensory qualities of diets might alter dietary self-selection was examined in three groups of rats self-selecting protein and carbohydrate from pairs of isocaloric diets in which the physical form (finely-milled casein/corn starch powder, granular casein/corn starch powder and gelled finely-milled casein/corn starch), but not the nutrient composition of each pair was varied. In addition, since the serotonergic drug fenfluramine has been frequently used to influence dietary selection, the effects of this drug on the selection of protein and carbohydrate from the three diets were also examined. The selection of particular diets and consequently protein and carbohydrate intake was markedly altered by the form of the diet. Furthermore, the effects of fenfluramine on diet selection were also modified significantly by the form of the diet. These results suggest that intake of certain nutrients is not strictly regulated at a particular fixed value and that drug-induced changes of self-selection behaviour must be interpreted cautiously.
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000378:metabolism; D002149:Energy Intake; D005277:Fenfluramine / Q000494:pharmacology*; D005518:Food Preferences / Q000187:drug effects; D008297:Male; D051381:Rats
D004044:Dietary Proteins; D005277:Fenfluramine