This presentation will summarize some of the key literature on neurological mechanisms and changes seen with bariatric surgery. In addition to the general literature, the talk will offer insights from an fMRI study we conducted related to sleeve gastrectomy. Using 18 sleeve candidates, fMRI was completed prior to surgery and then again one year following the procedure. Baseline activity in the NAcc and hypothalamus during desire for palatable food enhancement was significantly predictive of %TWL at 12 months (P (FWE)<0.05), superior to behavioral and hormone predictors, which did not significantly predict %TWL (P>0.10). Using stepwise linear regression, left NAcc activity accounted for 54% of the explained variance in %TWL at 12 months. Conclusions: Consistent with previous obesity studies, reward-related neural circuit activity may serve as an objective, relatively robust predictor of postsurgery weight loss. We now have follow-up analysis as well demonstrating that resting state functional connectivity in these patients is similarly predictive of post-surgical results.