The Night Eating Questionnaire (NEQ): psychometric properties of a measure of severity of the Night Eating Syndrome.

The purpose of this study was to evaluate the Night Eating Questionnaire (NEQ) as a measure of severity of the Night Eating Syndrome (NES). The 14-item NEQ assesses the behavioral and psychological symptoms of NES. The NEQ was evaluated in three samples: 1980 persons who completed the NEQ on the Internet; 81 persons diagnosed with NES; and 194 bariatric surgery candidates. Study 1, using principal components analysis, generated four factors (nocturnal ingestions, evening hyperphagia, morning anorexia, and mood/sleep) and an acceptable alpha (.70). Confirmatory factor analysis suggested that 99% of covariation among factors is accounted for by a higher-order construct. Study 2 found convergent validity of the NEQ with additional measures of night eating, disordered eating, sleep, mood, and stress. Study 3 compared scores from obese bariatric surgery candidates with and without NES and found appropriate discriminant validity of the NEQ. The NEQ appears to be an efficient, valid measure of severity for NES.