 For treatment-naïve patients, we are targeting 32 subjects for each group; however, we are going to include 37 in each group to allow for estimated drop-outs rate of 15. Subjects will be randomly assigned to 4 groups as follows: Group 1 includes non-obese controls BMI 25. They will receive one session of dietary and behavioral education. Groups 2, 3 and 4 include obese subjects BMI 30. Group 2 includes obese controls who will receive one session of dietary and behavioral education. Groups 3 and 4 will receive up to 6 weekly sessions followed by 12 monthly sessions of dietary and behavioral education. Orlistat and placebo will be prescribed for Groups 3 and 4 respectively. 