Effect of a high-fat diet on energy balance and thermic effect of food in hypothyroid rats.
We have carried out measurements of energy balance in hypothyroid rats fed a low-fat or a high-fat diet for eighteen days. We have also measured cephalic and processing thermic effect of food (TEF) after a low-fat or a high-fat meal. Body lipid gain, carcass lipid content and gross efficiency were significantly (P < 0.05) higher in hypothyroid rats fed a high-fat diet compared with hypothyroid rats fed a low-fat diet, while metabolizable energy intake and energy expenditure remained unchanged. Cephalic TEF after a low-fat meal was significantly (P < 0.05) lower in hypothyroid rats fed a high-fat diet compared with hypothyroid rats fed a low-fat diet, while it was significantly (P < 0.05) higher after a high-fat meal than after a low-fat meal in hypothyroid rats fed a high-fat diet. No significant variation was found in processing TEF after a low-fat or a high-fat meal. Our results indicate that hypothyroid rats are unable to develop increased energy expenditure and increased TEF in response to a high-fat diet.
Iossa
S
S
Dipartimento di Fisiologia Generale ed Ambientale, Università di Napoli, Italy.
Mollica
M P
MP
Lionetti
L
L
Barletta
A
A
Liverini
G
G
D000818:Animals; D001831:Body Temperature / Q000187:drug effects*; D004041:Dietary Fats / Q000008:administration & dosage* / Q000494:pharmacology; D004435:Eating / Q000502:physiology*; D004734:Energy Metabolism / Q000187:drug effects*; D007037:Hypothyroidism / Q000378:metabolism* / Q000503:physiopathology*; D008297:Male; D010101:Oxygen Consumption; D051381:Rats; D017208:Rats, Wistar
D004041:Dietary Fats