Current levels of obesity have been described as a 'health time bomb', with over half the population in Northern Ireland reported to have a significant weight problem. World'ide levels are also at epidemic proportions, with the World Health Organisation estimating that more than 300 million people are obese worldwidc mainly as a result of behaviour including poor dict. TIIC widcr health risks of obesity are well documented as it is a significant risk factor for high blood pressure, heart disease, stroke, cancer and diabetes, and has been linked to a 9-year reduction in life expectancy. In order to reduce these health risks adult eating behaviour must be modified. Current models used in thc field - predominantly the TIleory of Planned Behaviour - only account for approximately one third of thc variancc in cx-plaining this behaviour, and tllcse figurcs could be improved upon if existing knowledge was integrated in a systematic manner. Stage 1 of this research involved conducting a systematic review to answer tile question: 'What are the cognitive factors influencing adult eating behaviourT TIle review aimed to identifY all available evidence to reach an unbiased conclusion about tile cognitive variables which are important correlates of eating behaviour. At Stage 2 the results from tile review were used to inform a pilot survey examining healthy eating behaviour via a food frequency questionnaire (FFQ) along with tile key psychological factors identified. Path analysis resulted in tile development and construction of a new social-eognitive model of adult eating behaviour, and additionally of healthy eating intention. TIle key findings showed that self-cfficacy most strongly predicted healtlly eating behaviour, along with the acceptance of a diet-health relationship, perceived health benefits from a healthy diet and knowledge. Incorporating tllese findings in future tlleoretical intcn'cntions targcting healthy eating ,will consequently lead to an increase in successfully predicting and modifying adult eating behaviour.