Gastric bypass surgery is an effective long-term weight loss intervention. Key to its success appears a putative shift in food preference away from high-energy-density foods associated with a reduced appetitive drive and loss of neural reactivity in the reward system of the brain towards food. Post-prandial exaggerated satiety gut hormone responses have been implicated as mediators. Whilst the positive impact of bariatric surgery on both physical and psychological outcomes for many patients is clearly evident, a subset of patients appear to be detrimentally affected by this loss of reward from food and by a lack of alternative strategies for regulating affect after surgery. Mindfulness training has emerged as a potential tool in reducing the need for immediate reward that underpins much of eating behaviour. Further research is needed to help identify patients who may be more vulnerable after gastric bypass and which forms of support may be most beneficial.