Oxidative and nonoxidative macronutrient disposal in lean and obese men after mixed meals.
Oxidative and nonoxidative macronutrient disposal rates were measured in lean and obese males randomly fed mixed meals containing 0, 33, 67, 100, and 134 kJ/kg fat-free mass (0, 8, 16, 24, and 32 kcal/kg). Body composition, preprandial and postprandial energy expenditure, and macronutrient concentrations in the extracellular space were measured. Relationships among carbohydrate, fat, and protein disposal rates; body weight; and body composition were examined. Oxidative and nonoxidative disposals of macronutrients were not different between the lean and obese groups. Glucose was preferentially oxidized and fat was preferentially stored after nutrient ingestion. Macronutrient storage increased linearly with caloric intake. Oxidative and nonoxidative macronutrient disposals were completed within 8 h after ingesting the meals. Serum insulin concentrations rose to 3000-6000 pmol/L in two obese men after their two largest meals. Eight hours after nutrient ingestion, concentrations of macronutrient substrates, metabolic products, and insulin were indistinguishable from preprandial values.
Owen
O E
OE
Department of Internal Medicine, Southern Illinois University School of Medicine, Springfield 62794-9230.
Mozzoli
M A
MA
Smalley
K J
KJ
Kavle
E C
EC
D'Alessio
D A
DA
D000328:Adult; D001806:Blood Urea Nitrogen; D001823:Body Composition; D002153:Calorimetry, Indirect; D004040:Dietary Carbohydrates / Q000378:metabolism*; D004041:Dietary Fats / Q000378:metabolism*; D004044:Dietary Proteins / Q000378:metabolism*; D002149:Energy Intake; D004734:Energy Metabolism; D005110:Extracellular Space / Q000378:metabolism; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005502:Food; D005947:Glucose / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D009765:Obesity / Q000378:metabolism*; D010084:Oxidation-Reduction
D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D005947:Glucose