Preabsorptive factors are not the main determinants of intake depression induced by a high-protein diet in the rat.
The factors involved in the depression of food intake produced by a high-protein diet are still poorly understood. The aim of this study was to assess the role of several preingestive or preabsorptive factors likely to influence food intake when rats were fed ad libitum. Food intake was measured after modifying the composition of the high-protein diet, i.e., the type of proteins, or carbohydrates. Moreover, correlations between high-protein diet intake and the quantity of fluid ingested or stomach volume were studied. By varying the carbohydrate composition (sucrose/cornstarch) and the protein source (soy or gluten or total milk protein) of high-protein diets, we modified the orosensory properties of these diets. However, no differences in food intake were observed between these groups of rats during the transition phase or after adaptation, except during the first day of soy- or gluten-based diets when the depression of food intake was intensified. The depression of high-protein diet intake was neither the consequence of any delay necessary to increase the fluid intake induced by eating a high-protein diet nor due to a marked increase in stomach volume, which might explain enhanced satiety and decreased food intake through the activation of vagal afferent fibers. Our experiments do not indicate a preponderant role for oropharyngeal or preabsorptive factors in the depression of food intake induced by a high-protein diet.
L'Heureux-Bouron
Diane
D
Institut National de la Recherche Agronomique, Unité INRA-INAPG 914 de Physiologie de la Nutrition et du Comportement Alimentaire, Institut National Agronomique Paris-Grignon, 16 rue Claude Bernard, F75231 Paris Cedex 05, France.
Tomé
Daniel
D
Bensaid
Ahmed
A
Morens
Céline
C
Lacroix
Magali
M
Huneau
Jean François
JF
Fromentin
Gilles
G
D000818:Animals; D004032:Diet; D004040:Dietary Carbohydrates / Q000494:pharmacology; D004044:Dietary Proteins / Q000494:pharmacology*; D004326:Drinking / Q000502:physiology; D004435:Eating / Q000187:drug effects* / Q000502:physiology*; D002149:Energy Intake / Q000187:drug effects / Q000502:physiology; D005518:Food Preferences / Q000187:drug effects / Q000502:physiology; D007408:Intestinal Absorption / Q000502:physiology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013270:Stomach / Q000033:anatomy & histology; D013395:Sucrose / Q000494:pharmacology; D013549:Sweetening Agents / Q000494:pharmacology
D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D013549:Sweetening Agents; D013395:Sucrose