Psychometric properties of the 26-item eating attitudes test (EAT-26): an application of rasch analysis

BACKGROUND: The 26-item Eating Attitudes Test (EAT-26) is a commonly used tool to assess eating disorder risk. The purpose of this study was to examine the psychometric properties of the EAT-26 with a combined sample: (1) of adults with overweight and obesity enrolled in a behavioral weight loss program and (2) general adult sample (n = 469; age = 36.17 ± 17.83 years; female = 72.5%; white = 66.3%; obese BMI category = 58%). METHODS: Rasch modeling was used to assess model-data fit, create an item-person map to evaluate relative distribution items and persons, item difficulty, and person’s eating disorder (ED) risk level of the EAT-26. Differential item functioning (DIF) and rating scale functioning of the EAT-26 were also evaluated using Rasch analysis. RESULTS: A total of 7 misfit items were removed from the final analysis due to unacceptable Infit and Outfit mean square residual values. The item-person map showed that the items were biased toward participants with moderate to high levels of ED risk and did not cover those who had low risk for having an ED (< − 1 logits). The DIF analyses results showed that none of the items functioned differently across sex, but 5 items were flagged based on obesity status. The six-category Likert-type rating scale did not function well indicating a different response format may be needed. CONCLUSION: Several concerns were identified with the psychometric evaluation of the EAT-26 that may question its utility in assessing ED risk in individuals at low risk for ED, within samples of people who have overweight and obesity seeking weight loss treatment. PLAIN ENGLISH SUMMARY: The 26-item Eating Attitudes Test is a self-rated measure of eating attitudes that measures symptoms and concerns of eating disorders (ED). Very little is known about how this instrument performs differently based on individual factors like body mass index (BMI) and sex (male/female). We used an advanced measurement theory (i.e., Rasch analysis) to determine if the EAT-26 is an adequate measure to detect disordered eating in men and women of different BMIs. Results indicated that the EAT-26 was biased toward participants with moderate to high levels of disordered eating risk and did not adequately detect individuals at low risk for disordered eating. The EAT-26 did not function differently based on sex (male/female). However, five questions did function differently based on obesity status (those without obesity/ those with obesity). Finally, we observed the six-category rating scale did not function appropriately and that a new response format may be warranted. In sum, there were several issues (e.g., poor rating scale and different item functioning) with the EAT-26 and future work should develop screening tools that detect low risk of disordered eating as well as function well in adults with overweight and obesity. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40337-022-00580-3.