Meal-induced thermogenesis and macronutrient oxidation in lean and obese women after consumption of carbohydrate-rich and fat-rich meals.
OBJECTIVE
To examine differences in meal-induced thermogenesis and macronutrient oxidation between lean and obese women after consumption of two different isocaloric meals, one rich in carbohydrate (CHO) and one rich in fat.


METHODS
A total of 19 lean and 22 obese women were studied on two occasions, 1 wk apart. In one visit they consumed a CHO-rich meal and in the other visit a fat-rich meal. The two meals were isocaloric and were given in random order. Resting energy expenditure and macronutrient oxidation rates were measured and calculated in the fasting state and every hour for 3 h after meal consumption.


RESULTS
Meal-induced thermogenesis was not different between lean and obese subjects after the CHO-rich (P = 0.89) or fat-rich (P = 0.32) meal, but it was significantly higher after the CHO-rich compared with the fat-rich meal in the lean and the obese individuals (P < 0.05). Protein oxidation rate increased slightly but significantly after the test meals in both groups (P < 0.01). Fat oxidation rate decreased after consumption of the CHO-rich meal (P < 0.001), whereas it increased after consumption of the fat-rich meal in both groups (P < 0.01). CHO oxidation rate increased in both groups after consumption of the CHO-rich meal (P < 0.001). Oxidation rates of protein, fat, and CHO during the experiment were not significantly different between lean and obese participants.


CONCLUSIONS
Meal-induced thermogenesis and macronutrient oxidation rates were not significantly different between lean and obese women after consumption of a CHO-rich or a fat-rich meal.
Tentolouris
Nicholas
N
First Department of Propaedeutic Medicine, Athens University Medical School, Laiko General Hospital, Athens, Greece. ntentol@med.uoa.gr
Alexiadou
Kleopatra
K
Kokkinos
Alexander
A
Koukou
Eustathia
E
Perrea
Despoina
D
Kyriaki
Despoina
D
Katsilambros
Nicholas
N
D000328:Adult; D004040:Dietary Carbohydrates / Q000378:metabolism*; D004041:Dietary Fats / Q000378:metabolism*; D005260:Female; D006801:Humans; D015227:Lipid Peroxidation; D009765:Obesity / Q000378:metabolism / Q000503:physiopathology*; D010084:Oxidation-Reduction; D050050:Protein Carbonylation; D012016:Reference Values; D022722:Thermogenesis / Q000502:physiology*
D004040:Dietary Carbohydrates; D004041:Dietary Fats