Evaluation of a Quantitative Food Frequency Questionnaire for 5-Year-Old Children in an Asian Population

Abstract

Food frequency questionnaires are often used to assess dietary intakes due to their ability to assess intake over extended periods, their low respondent burden and cost-effectiveness. A quantitative food frequency questionnaire (FFQ), which includes locally appropriate food items for five-year-old children in a multi-ethnic Asian population was developed, but its validity has not previously been evaluated. To evaluate the relative validity of a newly developed FFQ as a dietary assessment tool for five-year-old children in a multi-ethnic Asian population. The 112 food item FFQs were administered by trained interviewers to caregivers of children. Frequency of food items consumed in the previous month and portion size information were collected. The FFQs were evaluated against three-day non-weighed diet records (DR) completed by caregivers. The dietary data of 361 children aged five years from the Growing Up in Singapore Towards healthy Outcomes (GUSTO) mother-offspring cohort were collected in 2015-2016. Nutrients of interest included energy, macronutrients, fibre, cholesterol, vitamin A, beta-carotene, calcium and iron, calculated from the FFQs and DRs. Nutrient intakes according to FFQs in relation to DRs were assessed using Pearson’s correlation, Lin’s concordance, Bland-Altman plots, quintile joint classification and Cohen’s kappa statistics. The highest energy-adjusted correlation (Pearson’s r = 0.71) and concordance (Lin’s concordance = 0.69) were observed for calcium. Fibre, saturated fat, PUFA, cholesterol and iron also showed correlation coefficients and concordance of at least 0.40. Bland-Altman plots suggested no substantial bias across ranges of intakes for the nutrients with correlations and concordance of 0.40 or above. Quintiles joint classification showed substantial agreement for calcium (κ = 0.66), and moderate agreement for iron, fibre, saturated fat, polyunsaturated fat and beta-carotene (κ = 0.59, 0.54, 0.49, 0.44, 0.43, respectively). The newly developed FFQ is in reasonable agreement with DR for estimating intakes of calcium, fibre, saturated fat, PUFA, cholesterol and iron. In addition, the FFQ is able to classify children according to quintiles of nutrient intakes, with moderate to substantial quintile agreements between FFQ and DR for calcium, iron, fibre, saturated fat, PUFA and beta-carotene. To assess the remaining nutrients, DR method is recommended instead of the FFQ.