The global diabesity epidemic is arguably more pronounced in certain high risk groups. Those with enduring severe mental illness are one such risk group. Greater than 50% are obese by BMI and about 80% have waist circumferences exceeding gender and ethnically adjusted IDF cutoffs. Patients in this high risk group respond to exercise interventions with greater facility than dietary interventions. To explain this neuropsychiatric models of reward and addiction can be used to show that where there is primary and secondary (neuroleptic-induced) anhedonia, and reduction in the motivational salience of everyday rewards, smoking and food become primary targets for maintaining motivation. As in standard addiction models, only food and nicotine are able to drive ventral striatal dopamine systems adequately. This is further exacerbated by the very high ingestion of fructose-laden soft drinks (~1.5 L/day) which further stimulates the hedonic associations with food ingestion through its extra sweetness. This talk will focus on aspects of the behavioural and neuroscience underlying ‘food addiction’.