Evaluative conditioning of attitudes towards nutrition: a systematic review of research using food and body stimuli

Abstract

This systematic review examined studies investigating evaluative conditioning (EC) effects using food stimuli as conditioned stimuli (CS) and body silhouettes as unconditioned stimuli (US). Following PRISMA guidelines, 162 records were identified, of which three studies met the inclusion criteria and were included in the final analysis of methodological characteristics and outcomes. The review focused on technical elements (stimulus types, presentation parameters, trial numbers) and functional properties (conditioning effects, extinction patterns) of EC procedures. Analysis revealed consistent evidence for successful conditioning effects, particularly when pairing food images with obese body shapes, resulting in decreased CS ratings post-conditioning (effect sizes ranging from r = .26 to .41). However, studies exhibited considerable methodological heterogeneity in stimulus presentation times (400-7000ms), trial numbers (18-144), and measurement approaches. Key procedural variations included gender representation in US stimuli, CS categorization (single items vs. food categories), and assessment methods (explicit ratings vs. implicit measures). The findings highlight the need for greater methodological standardization in EC research using food-body associations, while suggesting EC's potential utility in modifying food-related attitudes. Future research directions should address gender balance in sampling, standardization of stimulus sources, and investigation of potential mediating mechanisms. The results point to potential relevance for nutrition education and public health contexts, while also underscoring the importance of further research on the effectiveness, stability, and ethical implications of such applications.