1) To determine the degree of oxidation of two biosynthetically derived triglycerides containing a high proportion of 13C-labeled oleic acid as compared to the oxidation of a synthetic triglyceride containing all 1-13C- oleic acid, a more expensive 13C substrate. 2) Characterization of fat oxidation by the study population with respect to total body fat as determined from total body measurement and by quantification of lipoprotein lipase activity.