Development and validity of semi-quantitative food frequency questionnaire as a new research tool for sugar intake assessment among Indonesian adolescents

Robust evidence has shown that sugar is a major contributor to obesity and Non-Communicable Diseases (NCDs). However, there have not been sufficient tools to estimate sugar intakes. Therefore, developing a new and valid tool to assess sugar intake, based on cultural eating habits, is crucial. The study was done in two phases; the first focused on the development of Semi-quantitative Food Frequency Questionnaire (SFFQ), and the second focused on researching the validity of the questionnaire. Food items in the SFFQ were selected from the latest national survey review, exploratory survey, and food market observation. Forty-nine food items were included in the final SFFQ with five open-ended questions for fruit groups. One hundred and six adolescents aged 15–17 years participated in the study. The total sugar intake among the adolescents was 58.80 g/day (52.7 g sucrose; 1.47 g fructose; 1.49 glucose) which contributed to 11.6% of the total energy intake per day. The reliability analysis showed a good agreement between the two administered SFFQs in a one-month interval. The relative validity results, using 6-days food diaries as a reference method, demonstrated a superior ability to rank individuals into the same and adjacent classification and only <10% gross misclassification in all sugar intakes. The developed SFFQ in turn has been proven to have moderate to good validity and be applicable for a larger epidemiological study.