Predictors of Lorcaserin-Induced Weight Loss

In phase 1, at Weeks 1 and 5, participants will take the weight loss drug lorcaserin or placebo for 7 days. At Week 5 participants will receive whichever treatment they did not receive at Week 1. At the end of Weeks 1 and 5, participants will have a lumbar puncture (spinal tap) to collect cerebrospinal fluid (CSF) for neuropeptide and hormone analyses, including proopiomelanocortin (POMC), Agouti-related protein (AgRP) and cortisol. Blood will also be obtained for neuropeptide and hormone analyses. Breakfast will be served to participants who will then complete an eating behavior profile. A laboratory test meal will be performed 4h after breakfast. After completing both the 7 day lorcaserin and placebo studies, participants will then continue on Phase 2 of the study, which includes treatment with lorcaserin for 24 weeks. Subjects will receive nutritional counseling to reduce their daily caloric intake to 600 kcal below their calculated caloric requirement and will be encourage to exercise moderately for 30 minutes daily. Participants will visit the clinic monthly during the 24 week study period for nutritional counseling, review of food diaries, vital signs and safely labs. Blood will also be obtained for neuropeptide peptide and hormone analyses. At the end of the 24 week period subjects will come for a final study visit, including a lumbar puncture, blood sample, breakfast, an eating behavior profile and a test meal.