Development and Validation of a Semi-Quantitative Food Frequency Questionnaire to Assess Diets of Korean Type 2 Diabetic Patients

BACKGROUND Our aim was to assess the validity of a semi-quantitative food frequency questionnaire (FFQ) by comparison with the 3-day diet record (DR) in patients with type 2 diabetes. METHODS Eighty five type 2 diabetic patients (aged 33 to 70 years) from the Korean National Diabetes Program (KNDP) completed 3-day DR and FFQ. The FFQ was designed to reflect the eating pattern of Korean type 2 diabetic patients, and was based on the 2003 Korean National Health and Nutrition Examination Survey. The FFQ consists of 85 food items and 12 food groups. The validity of FFQ was assessed by comparison with the 3-day DR. RESULTS The mean age was 49 +/- 10 years. Clinical characteristic including body weight, diabetic duration, and HbA1c were not different from the total cohort subjects (n = 1,478). There were no significant differences in the mean intake of protein, fat and calcium estimated by the FFQ and the 3-day DR. Energy and carbohydrate estimated by the FFQ were higher than those estimated by the 3-day DR. The correlation coefficient was highest for energy (r = 0.740; P < 0.00) and lowest for iron (r = 0.269; P < 0.05). The Kappa values for energy, carbohydrate, protein, fat and calcium were 0.54, 0.37, 0.36, 0.46, and 0.19, respectively. CONCLUSION The FFQ is a reasonable instrument for assessing the intake of most macronutrients in Korean type 2 diabetes, although careful consideration is required for the food groups and nutrients for which the FFQ had low validity.