Psychometric Evaluation of the German Version of the Impact of Weight on Quality of Life-Lite (IWQOL-Lite) Questionnaire

Objective: To evaluate the psychometric properties of a German version of the Impact of Weight on Quality of Life-Lite (IWQOL-Lite) questionnaire. Method: IWQOL-Lite scores were obtained from 351 overweight/obese individuals and 127 lean adult volunteers. In addition, a subgroup of 126 obese subjects completed also the German versions of the 36-item short-form health survey (SF-36), the Beck Depression Inventory (BDI), the Eating Disorder Examination-Questionnaire (EDE-Q), and the German validated version of the Three-Factor Eating Questionnaire (TFEQ). Results: The German version of the IWQOL-Lite has psychometric properties comparable to those found for the original version and demonstrates high internal consistency and excellent construct validity. Furthermore, the German IWQOL-Lite clearly discriminates between groups based on BMI on all subscales and the total score. Conclusion: The results of the present study suggest that the German IWQOL-Lite is a psychometrically validated instrument with which to measure weight-specific health related quality of life.