Validity and reliability of the Iranian version of the Yale Food Addiction Scale for obese women.

OBJECTIVE The face and construct validity of the Iranian version of the Yale Food Addiction Scale (YFAS) was evaluated, and the convergent validity and test-retest reliability of both Iranian and original versions of YFAS for obese women were assessed. DESIGN The internal consistency of the YFAS was analysed. Exploratory factor analysis for dichotomous data was performed by varimax rotation, polychoric correlation coefficients and confirmatory factor analysis (CFA). Convergent validity was established by evaluating the correlation between the original and the Iranian versions of YFAS and the Binge Eating Scale (BES). The intraclass correlation coefficient (ICC) was measured between test-retest results. SETTING A weight management clinic in Tehran. PARTICIPANTS 450 obese women. RESULTS The single-factor structure indicated that the factor loadings for all the items were > 0·5, except for three items (explained proportion variance = 51 %). Based on CFA, the single factor had a better fit to the data after excluding three items. The Kuder-Richardson-20 coefficient was 0·86 for the total twenty-two items. The symptom count and diagnostic version of both the Iranian (ICC = 0·92 and 0·87, respectively) and original YFAS (ICC = 0·92 and 0·86, respectively) were stable over 2 weeks. Both the symptom count and the diagnostic version of these two scales had significant correlations with the measures of BES (P < 0·001). CONCLUSIONS The initial reliability and validity of the Iranian version of the YFAS among obese women are supported. Further studies should be conducted on men and normal/overweight samples.