Reliability and validity of a computerized questionnaire to measure fat intake in Belgium Corneel Vandelanotte a, *, Christophe Matthys b , Ilse De Bourdeaudhuij a a Faculty of Medicine and Health Sciences, Department of Movement and Sport Sciences, Ghent University, Watersportlaan 2, 9000 Ghent, Belgium b Faculty of Medicine and Health Sciences, Department of Public Health, Ghent University,Watersportlaan 2, 9000 Ghent, Belgium Received 1 October 2003; accepted 15 December 2003 Abstract This study evaluated the reliability and validity of a Belgian computerized questionnaire to measure fat intake. A total of 86 adults completed a 48-item computerized fat intake questionnaire, subse- quently kept a 7-day diet record, and finally completed the questionnaire again. For validity, a Pearson correlation of 0.67 for total fat intake and of 0.60 for percent energy from fat were found between the computerized questionnaire and the diet records. Gross misclassification between the two methods was 5.8% for total fat intake and for percent energy from fat. Cohen’s  values were respectively 0.27 and 0.29. For reliability, intraclass correlation coefficients ranged from 0.70 to 0.87 between the two administrations of the computerized fat intake questionnaire. Gross misclassification between the administrations was 1.2% for total fat intake and for percent energy from fat,  values were respectively 0.64 and 0.50. These results indicate that this fat intake questionnaire has an acceptable reliability and validity. © 2004 Elsevier Inc. All rights reserved. Keywords: Diet records; Fat intake; Food frequency questionnaire; Computer; Validation; reliability 1. Introduction The Belgian population has an average fat intake of about 42% energy from fat, which is well above the recommended 30% energy from fat [1–3]. This places most of these * Corresponding author. Tel.: 32.(0)9.264.63.23; fax: 32.(0)9.264.64.84. E-mail address: Corneel.Vandelanotte@UGent.be (C. Vandelanotte, Ph.D. student) . www.elsevier.com/locate/nutres Nutrition Research 24 (2004) 621– 631 0271-5317/04/$ – see front matter © 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.nutres.2003.12.008