A laboratory investigation of stress-induced eating behaviour
Studies suggest that the experience of anxiety or exposure to stressful events may contribute to the 'disinhibition' of dietary restraint (diet breaking) and promote symptoms of binge eating and bulimia. Mechanisms by which such factors lead to overeating are not clearly understood, and competing theoretical explanations have not been sufficiently tested using reliable and robust methodological approaches within the laboratory. The current research adopted a psychophysiological approach to the measurement of stress-eating and information processing, using an aggregation of experimental paradigms taken from cardiovascular/stress and dietary restraint literatures, to investigate the effects of self-directed ego threat stress on female restrained eaters, with and without bulimic symptoms. The first main aim was to test two competing theoretical explanations of overeating [bingeing] in response to stress - the limited capacity versus the 'escape' theory. Taken together, the results obtained from three experiments revealed only limited support for the limited capacity model. Some support was obtained for the 'escape' theory. These results were also discussed in relation to restraint theory, and the continuum and new generation cognitive models of BN. The second main aim was to ascertain the existence of information processing and memory biases for scheme-relevant cues unrelated to eating [self-directed ego threat] in the two target populations. Results from these analyses provided further support for restraint theory, the 'escape'theory of bingeing, and the continuum and new generation cognitive models of BN. Two more minor aims of the current research were a) to assess arousal responses in response to post-stress food ingestion in the two target populations, b) to assess whether temporal/habituation effects occurred in respect of information processing of ego-threat stimuli.
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