Background. The current study investigated the fundamental nature of the cognitive processing deficit that has been demonstrated to be associated with dieting to lose weight. Previous work has characterized this deficit as being primarily one of a reduction in working-memory capacity. The present study investigated the particular components of the working-memory system affected during dieting.

Method. A sample of female subjects was classified as either low/medium restrained eaters (N=34), highly restrained eaters (N=18) or current dieters (N=19), based on their responses to a modified version of the Dutch Eating Behaviour Questionnaire (DEBQ). Each subject completed tasks that assessed the Visuo-Spatial Sketchpad (mental rotation), Phonological Loop (effect of phonological similarity on recall) and the Central Executive (Tower of London Task) components of working memory.

Results. Those subjects who reported themselves to be currently dieting displayed poorer recall on the Phonological Loop task and slower planning times on the Tower of London Task. Performance on both these tasks correlated significantly with a self-report measure of body shape concern.

Conclusions. These results support the hypothesis that the mediating variable in this deficit is that of preoccupying cognitions concerning food and body shape.