Introduction: Obesity is one of the leading causes of preventable morbidity and mortality world-wide. The behavioural nature of the condition has been highlighted by the fact that it is largely the result of an energy imbalance between calories consumed and calories expended. In that respect, obesity related morbidity and mortality can be reduced through preventive behaviours. As behavioural scientists, economists have done little to date to explain and understand why the demand for obesity preventing activities is low. The aim of this paper is to develop an economic theory-based dynamic model to gain better understanding of people’s obesity preventive behaviours. Methods: A literature search using a PICO approach was developed to identify the relevant variables considered to influence the demand for obesity preventive goods. To inform the model, a framework was developed to group variables and help determine appropriate linkages between them. Results: Anchors, anxiety and anxiety driven variables are fundamental influences of people’s risk reduction actions. The anchors, which are environmental as well as personal in character, serve as references and stimulate anxieties. However, anxiety levels are driven by many other variables including stigma and perceived health outcomes. In response to one’s anxiety an individual will take actions which can be explained, at least in part, by conventional economic theories particularly in terms of costs and utilities. Conclusions: Conventional economic theories of consumer behaviour cannot fully explain the demand for obesity preventive goods. The model demonstrates that many factors have to be considered including health economic, psychological and behavioural economic theories. The model should be tested through a well designed questionnaire before using it in a general adult population.

obesity, Behavioural Economics, preventive goods, demand, modelling