Regulating Unhealthy Snacking Behaviour: The Interplay Between Desire and Self-control

Author: Ashleigh Haynes

Haynes, Ashleigh, 2015 Regulating Unhealthy Snacking Behaviour: The Interplay Between Desire and Self-control, Flinders University, School of Psychology

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The dominant view of self-control is that it is the ability to override immediate impulses or desires in order to pursue a long-term goal. However, self-control research has often neglected the importance of empirically testing desire, and focused more on behavioural restraint and motivation toward long-term goals. This thesis presents the results of six empirical studies exploring the interplay between self-control both at dispositional and situational levels and desire in the regulation of unhealthy snack consumption.

While previous theorists had proposed desire to be in part predicted by positive implicit evaluations of relevant stimuli, Chapter 2 presents the first empirical test of this relationship. A negative implicit evaluation of unhealthy snack food predicted lower temptation to indulge, which mediated the relationship between negative implicit food evaluations and lower intake of unhealthy food. Following these findings, Chapters 3 and 4 report studies testing computer-based tasks aimed at retraining these implicit food evaluations. Findings suggested that such interventions may be more successful at reducing snack intake if targeted at individuals with lower trait self-control, or implemented in situations where individuals lack inhibitory control resources, as low self-control appeared to enable overcoming of trained impulses toward unhealthy food. Chapter 4 also showed that high situational self-control may enable the downregulation of an automatic positive evaluation of food stimuli before it becomes a conscious temptation.

The relationship between desire, snack intake, and experimentally-manipulated situational self-control was further explored in Chapter 5. While it appeared as though individuals with higher self-control were better able to overcome desire to indulge in unhealthy snack food, rather than experiencing weaker desire leading to lower snack intake, the effect was not statistically significant. A similar question about whether dispositional self-control enables the overcoming of desire or instead weakens desire, was tested in Chapter 6. Results revealed that individuals with higher trait self-control ate less snack food than their low self-control counterparts, which was accounted for by the lower desire experienced.

Chapter 7 aimed to test a potential explanation derived from counteractive control theory for the relationship between trait self-control and lower desire observed in Chapter 6. However, the relationship between higher self-control and lower desire was not replicated in Chapter 7. Nevertheless, the findings did suggest that when the goal of weight management was highly cognitively accessible, individuals with high trait self-control experienced less intense temptation to indulge in unhealthy snack food and subsequently ate less.

Overall, the studies support the centrality of the experience of desire in the regulation of unhealthy snacking behaviour, and underscore the importance of this often overlooked variable as a target for interventions promoting effective regulation of unhealthy snacking, especially for individuals with low self-control. The findings also suggest that the role of self-control at both trait and state levels is more complex than simply overriding strong desires that conflict with valued goals to enact goal-consistent behaviour, but that self-control may contribute to weaker desire.

Keywords: self-control, unhealthy food intake, desire

Subject: Psychology thesis

Thesis type: Doctor of Philosophy
Completed: 2015
School: School of Psychology
Supervisor: Professor Eva Kemps