Worldwide rates of obesity have dramatically increased in the last few decades. The impact on those involved and on health care systems continues to be huge. Psychological research has attempted to understand the factors and processes implicated in maladaptive overeating behaviour with the aim of assisting in alleviating it, whether associated with a physical or mental health need. This thesis investigated the relationship between biases in attention to food-related cues and the self-reported eating style known as ‘external eating’ (eating in response to external food cues). A systematic search of the literature found 15 papers that examined the relationship between these factors. These studies used a range of methodologies and found varying results. The literature review established that there is a significant relationship between external eating and attentional bias for food cues, such that higher levels of bias are linked with higher levels of external eating. An experiment was designed to measure attentional bias to food cues in high and low external eaters from a non-clinical population using an antisaccade methodology. This tool measured attentional bias scores for the 39 participants in the two groups. In addition, participants completed a behavioural task of inhibitory control, as well as a range of questionnaire measures concerned with eating behaviour and mental health. With this novel methodology, a significant positive relationship was identified between external eating and attentional bias for food. Findings are discussed in relation to theoretical models of attentional bias and maladaptive eating behaviour. Clinical implications are explored and cognitive and behavioural interventions for overeating behaviour are discussed. Future research ideas are suggested with the aim of exploring further the role of eating styles and attentional biases in the development and maintenance of overeating behaviour.