Author: Isaac Williams
Williams, Isaac, 2025 The Interaction between Mood, Dietary Restraint, and Emotion Regulation on Eating Behaviour, Flinders University, College of Education, Psychology and Social Work
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Chronic dieters frequently experience lapses in long-term dietary adherence, with weight regulation strategies counterintuitively often leading to weight gain. Negative mood has consistently been shown to be a contributor to these lapses, leading to the (over)consumption of unhealthy foods. However, this effect of negative mood may be buffered by emotion regulation which influences the experience and expression of emotions. Accordingly, the present thesis aimed to investigate the interactions between mood, dietary restraint, and emotion regulation on eating behaviour, and did so across both experimental and naturalistic contexts. To comprehensively examine these interactions, the thesis distinguished between food choices and intake, and between real-time (state) versus chronic (trait) mood, both of which have been underexamined in the literature.
The thesis consists of a general literature review, three empirical studies, and a general discussion. The general introduction (Chapter 1) outlined the theoretical frameworks linking mood and emotion regulation to eating behaviour in restrained eaters, and identified gaps in prior research. In so doing, it informed the aims of the subsequent empirical studies.
Chapter 2 included two experimental studies that examined whether emotion regulation moderated the impact of a negative mood induction on food intake within a laboratory setting (Study 1) and food choices in an online task (Study 2) among restrained and unrestrained eaters. Study 1 found that restrained eaters consumed less healthy foods when in a negative mood compared to a neutral mood; however, this effect was not found for healthy food choices in Study 2. Contrary to prediction, emotion regulation did not moderate the effect in either study. The findings suggested that being in a negative mood may influence food intake and online food choices differently, and that time-pressured settings such as timed eating behaviour measures may not provide sufficient opportunity for effective emotion regulation.
Chapter 3 used a seven-day food diary to examine the impact of positive and negative state and trait moods on snacking behaviour in real-world settings, and the moderating role of emotion regulation herein. State mood was more likely to influence snacking behaviour than trait mood. Restrained eaters consumed more unhealthy snacks than unrestrained eaters when in a negative mood, whereas unrestrained eaters consumed more snacks overall than restrained eaters when in a positive mood. Emotion regulation was found to have a limited role, with restrained eaters with higher difficulties in emotional awareness and clarity consuming fewer unhealthy snacks, suggesting that the ability to recognise and label emotions may shape eating behaviour.
The general discussion (Chapter 4) integrated the empirical findings based on the theoretical frameworks of escape theory, dual-process models, and the process model of emotion regulation. The practical implications of the results were also outlined, as well as the strengths, limitations, and future research directions from the thesis, including the need for diverse samples and ecological momentary designs.
Overall, the thesis contributes to our understanding of mood-driven eating by demonstrating the differential effects of moods on food choices and intake. Specifically, the thesis found that state negative mood disrupts dietary adherence of restrained eaters, particularly in real-world environments. Emotion regulation was found to have a limited role within this interaction. The findings offer directions for real-time mood regulation strategies in order to improve dietary adherence and promote healthier eating among chronic dieters.
Keywords: Emotion, Emotion regulation, Dietary restraint, Food choice, Food intake
Subject: Psychology thesis
Thesis type: Doctor of Philosophy
Completed: 2025
School: College of Education, Psychology and Social Work
Supervisor: Eva Kemps