Akin to addictive behaviours, alterations in dopaminergic and opioid pathways, involved in the expectancy, appraisal and receipt of food reward appear to be important in the development and maintenance of obesity. Several components of the reward system, including the striatal nucleus accumbens and caudate nucleus (key to dopaminergic reward conditioning, expectancy and motivation), amygdala (emotional responses to rewarding stimuli), anterior insula (integrating gustatory and other sensory information) and OFC (reward value appraisal, cognitive control and attention) have been implicated. Activation in these areas to food cues not only predicts food consumption and choice, and prospective weight gain, but may be altered in obesity, predict the success of weight loss strategies, changes with successful weight loss, including surgical treatments, and is altered in specific eating behaviour psychopathology such as dietary restraint, dietary disinhibition, binge eating and hyperphagia in genetic obesity. Interestingly modulation of activation of these reward systems both at rest and in response to food stimuli by gut hormones has been described. Functional MRI offers a validated method of testing the effects of different bariatric surgeries on brain reward and cognitive control systems. Preliminary data from longitudinal fMRI studies suggest that RYGB may have beneficial effects on food hedonics including brain food reward systems, which may favour increased weight loss over BAND surgery. The differential effects of RYGB and BAND on brain food reward systems has not been tested, nor the relationship of these with behavioural and metabolic phenotypes (including exaggerated gut hormone release in RYGB) found in these two surgeries for obesity. The differential effects of RYGB and BAND surgery on brain structure including grey matter volume and white matter tract integrity has also not been examined. Understanding how different surgeries differentially affect eating behaviour and food reward on a functional and anatomical level in the brain may help establish the mechanism by which RYGB achieves greater success in treating obesity. This not only highlights the importance of gut-brain food hedonics in the treatment of obesity, including the development of novel, non-surgical treatments, but also raises the potential of more personalized approaches to surgical obesity treatments, according to relevant clinical, behavioural and metabolic phenotypes.