Energy restriction with protein restriction increases basal metabolism and meal-induced thermogenesis in rats.
We previously observed an increased sympathetic nervous system (SNS) activity that was partly responsible for a defect in the insulin secretion response to glucose after postweaning protein-energy restriction (PER) in female rats. These results, together with other data on low-protein feeding, suggested that a low protein-to-energy ratio (P/E) in the diet could stimulate energy expenditure (EE), but direct measurements of EE have never been reported under conditions of PER. The goal of the present study was thus to quantify the changes induced by PER to body composition, the various parameters of EE, and plasma triiodothyronine levels. PER induced severe growth retardation, but the subcutaneous white and interscapular brown adipose tissue masses were preserved. Basal metabolism, meal-induced thermogenesis, and triiodothyronine levels were increased, but substrate utilization by the working muscles was unaffected. Meal-induced thermogenesis was increased by spontaneous activity in PER rats only. These results suggest that rats adapt to a low P/E in the diet by burning part of their excess nonprotein energy and storing the remaining excess in subcutaneous adipose tissue.
Even
Patrick C
PC
Laboratoire de Physiologie de la Nutrition et du Comportement Alimentaire, Unité Mixte de Recherche 914, Institut National de la Recherche Agronomique, Institut National Agronomique Paris-Grignon, 75231 Paris Cedex 05, France. even@inapg.fr
Bertin
Eric
E
Gangnerau
Marie-Noelle
MN
Roseau
Suzanne
S
Tome
Daniel
D
Portha
Bernard
B
D000818:Animals; D001481:Basal Metabolism; D001823:Body Composition; D001835:Body Weight; D004044:Dietary Proteins / Q000008:administration & dosage*; D004435:Eating / Q000502:physiology*; D004734:Energy Metabolism; D005260:Female; D018482:Muscle, Skeletal / Q000378:metabolism; D019518:Postprandial Period; D051381:Rats; D017208:Rats, Wistar; D012143:Respiratory Physiological Phenomena; D022722:Thermogenesis / Q000502:physiology*; D014284:Triiodothyronine / Q000097:blood
D004044:Dietary Proteins; D014284:Triiodothyronine