Fractional oxidation of chylomicron-derived oleate is greater than that of palmitate in healthy adults fed frequent small meals.
Differences in oxidation of individual dietary fatty acids could contribute to the effect of dietary fat composition on risk factors for non-insulin-dependent diabetes mellitus and cardiovascular disease. Using a novel stable isotope technique, we compared fractional oxidation of chylomicron-derived oleate and palmitate in 10 healthy adults in a crossover study. 1-(13)C-labeled oleate or palmitate was emulsified into a eucaloric formula diet administered each 20 min for 7 h to produce a plateau in excretion of (13)C label in breath CO(2). Unlabeled oleate and palmitate each provided 16% of dietary energy, and other fatty acids provided 8% of energy. Total dietary fat was 40% of energy, carbohydrate was 46%, and protein was 14%. Diet without tracer was fed for 2 h before beginning tracer administration to establish a baseline fed state. Relative oxidation of oleate versus palmitate was defined as fractional oxidation of oleate divided by fractional oxidation of palmitate. Relative oxidation averaged 1.21 (99.5% confidence interval = 1.03;-1.39), indicating that fractional oxidation of oleate was significantly greater than that of palmitate.
Schmidt
D E
DE
Children's Research Institute, The Ohio State University, Room W209, Children's Hospital, 700 Children's Drive, Columbus, OH 43205-2696, USA.
Allred
J B
JB
Kien
C L
CL
D000328:Adult; D002153:Calorimetry, Indirect; D002245:Carbon Dioxide / Q000378:metabolism; D002250:Carbon Radioisotopes / Q000493:pharmacokinetics; D002914:Chylomicrons / Q000737:chemistry*; D004032:Diet; D005230:Fatty Acids, Nonesterified / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D008297:Male; D019301:Oleic Acid / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*; D010084:Oxidation-Reduction; D010168:Palmitates / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*
D002250:Carbon Radioisotopes; D002914:Chylomicrons; D005230:Fatty Acids, Nonesterified; D010168:Palmitates; D002245:Carbon Dioxide; D019301:Oleic Acid