 Subjects were screened and then underwent baseline evaluation. The substudy evaluation measured 24-h energy expenditure and substrate utilization by using a whole-room indirect calorimeter. Dietary fat oxidation was measured by mixing 1-13Coleate and D31-palmitate into a breakfast meal and then collecting breath carbon dioxide and urine to measure the end products of oxidation. Subjects were then provided either 4 gd of 78 active CLA isomers 3.2 gd: 39.2 cis-9,trans-11 and 38.5 trans-10,cis-12 or 4 gd of safflower oil placebo as 1-g gel capsule supplements. The baseline evaluations were repeated 6 mo later. 