Author: Naomi Kakoschke
Kakoschke, Naomi, 2017 The Role of Automatic Processing of Food Cues in Unhealthy Eating Behaviour, Flinders University, School of Psychology
Terms of Use: This electronic version is (or will be) made publicly available by Flinders University in accordance with its open access policy for student theses. Copyright in this thesis remains with the author. You may use this material for uses permitted under the Copyright Act 1968. If you are the owner of any included third party copyright material and/or you believe that any material has been made available without permission of the copyright owner please contact copyright@flinders.edu.au with the details.
Recent empirical research and theoretical models have acknowledged that automatic processing of appetitive food cues is an important contributor to unhealthy eating behaviour. However, relatively little research has examined when, and for whom, automatic processing of food cues influences such behaviour. Therefore, the first aim of the thesis was to investigate automatic processing in conjunction with self-regulatory control or trait eating styles to gain a better understanding of unhealthy eating behaviour. The second aim was to determine whether interventions designed to modify automatic processes and/or selfregulatory control are effective for reducing unhealthy eating and/or promoting healthier eating. These two aims were addressed in a series of correlational and experimental studies.The thesis consists of six papers (two published, one under revision, and three under review). Study 1 examined the combined effects of cognitive bias (attentional and approach) and inhibitory control on unhealthy eating behaviour. It was found that a stronger approach bias for unhealthy food combined with lower inhibitory control predicted increased consumption of unhealthy food. Study 2 tested the effects of the affective aspect of automatic processing (implicit evaluation) and an emotional eating style on unhealthy eating behaviour. The findings showed that a positive implicit food evaluation (increased liking) predicted increased choice for unhealthy snack food in participants with lower emotional eating.Study 3 investigated the combined effects of approach bias for food and eating style on unhealthy food consumption in normal weight and overweight individuals using a pooled sample. Among overweight participants, an external and emotional eating style individually moderated the relationship between approach bias for unhealthy food and snack intake, such that approach bias was positively related to consumption in high external or emotional eaters, but negatively related in low external or emotional eaters. These interactions were not observed among normal weight participants.Studies 4 and 5 experimentally manipulated automatic processing and/or inhibitory control. These studies were preceded by a literature review on the effectiveness of approach bias modification as an intervention for reducing the consumption of appetitive substances in general. All of the reviewed studies (with one exception) that reported a positive outcome for consumption also showed a successful reduction of approach bias for appetitive cues. Study 4 demonstrated that the combined re-training of approach bias for unhealthy food together with inhibitory control was more effective than either task alone for reducing implicit liking of unhealthy food; however, no significant effects were found for food consumption. Approach bias re-training on its own did reduce unhealthy snack food choice. Study 5 found that the effect of approach bias re-training on subsequent consumption was moderated by trait impulsivity, such that only highly impulsive participants ate a greater proportion of healthy food following training. Overall, the findings contribute to emerging evidence for the role of automatic processing of appetitive food cues together with self-regulatory control and trait eating style in unhealthy eating behaviour. The results also contribute to a theoretical understanding of unhealthy eating based on recent dual-process models of behaviour (Strack & Deutsch, 2004), and inform the development of interventions designed to reduce such behaviour.
Keywords: Approach bias, automatic processing, food cues, eating behaviour, cognitive bias modification
Subject: Psychology thesis
Thesis type: Doctor of Philosophy
Completed: 2017
School: School of Psychology
Supervisor: Eva Kemps