Relative Validity and Reproducibility of a Short Food Frequency Questionnaire to Assess Nutrient Intakes of New Zealand Adults

Abstract

There is no recent validated short food frequency questionnaire (FFQ) for use in New Zealand (NZ) adults. This study aimed to evaluate the relative validity and reproducibility of a short FFQ in free-living NZ adults aged 30–59 years. A 57-item, semi-quantitative FFQ was developed and pre-tested. During a 12-month study period the FFQ was administrated twice with a 9-month interval between administrations. Four two-day diet records were collected at months 0, 3, 6, and 9 and a blood sample was taken at month 9. Spearman correlations were used to evaluate the validity of the FFQ with the eight-day diet records and selected biomarkers. Cross-classification analysis and the Bland–Altman method were used to assess the agreement between the FFQ and the diet record. Reproducibility over nine months was assessed using intra-class correlations. A total of 132 males and females completed both FFQs, the eight-day diet record, and provided a blood sample. The highest energy-adjusted correlation coefficients were observed for alcohol (0.81), cholesterol (0.61), and carbohydrate (0.61), with the lowest for sodium (0.29), thiamin (0.33), and niacin equivalents (0.34). More than three quarters of the participants were correctly classified into the same or adjacent quartile for most nutrients, with a low proportion of participants being grossly misclassified (<10%). For most nutrients, the limits of agreement from the Bland–Altman analyses were between 50% and 250%. A positive correlation was observed between dietary intakes and plasma biomarkers for all selected nutrients. The FFQ showed moderate to good reproducibility, with almost all reliability coefficients ranging from 0.60 to 0.80. This short FFQ was shown to validly and reliably rank individuals by their habitual intake of most major nutrients, indicating that the FFQ will offer a time-efficient way to assess the nutrient intake of NZ adults in future research.

A meta-analysis of the reproducibility of food frequency questionnaires in nutritional epidemiological studies

“…An overview of the retrieved studies assessing the reproducibility of FFQs is presented in Table 1 (detail information shown in Supplemental Table 1 ). Of the 123 articles included [ 4 , 10 – 13 , 15 – 18 , 20 , 21 , 23 – 134 ], two articles analyzed differences in different age groups [ 50 , 113 ], and five articles assessed the differences in reproducibility according to time intervals between repeated FFQs [ 39 , 91 , 96 , 113 , 134 ]. The extracted information on characteristics of the included studies is summarized in Table 1 (detail information shown in Supplemental Table 1 ).…”

“…A previous study reported that the ICCs of an FFQ comprising 255 items ranged from 0.69 (fat) to 0.84 (vitamin A) in Moroccan adults [ 19 ]. A shorter FFQ assessing the average consumption of 57 food items was reported to have a reliability coefficient ranging from 0.56 to 0.70 [ 20 ]. Therefore, FFQ items may induce differences in reproducibility.…”

The relationship between maternal dietary patterns during pregnancy in women with gestational diabetes mellitus and infant appetitive feeding behaviour at 6 months

“…Our sole reliance on maternal self-report of dietary intake and infant feeding behaviour, as opposed to observed measures of data collection, may have introduced recall and social desirability bias [53][54][55] . However, the FFQ we used was shown to have acceptable to good validity when compared to the 8-day dietary record 56 , and dietary patterns derived from PCA and food records are reported to be similar [57][58][59] . Additionally, PCA is inherently subjective, with a tendency towards interpretation bias 60,61 .…”

“…Data on food consumption was collected from study participants via a self-administered, 1-month recall, FFQ at 36 weeks' gestation. The FFQ was a customized version of the 163-item semi-quantitative FFQ developed by Willett 63 , with changes made to reflect local dietary habits www.nature.com/scientificreports/ as per the nationally-representative nutrition survey available at the time 64 , and further informed by two focus groups of 21 adults aged 30-59 years in New Zealand 56 . The questionnaire comprised 65 questions, of which 57 were grouped as dairy, eggs and meat, fish and seafood, bread, cereals and starches, fruits, vegetables, fast foods, beverages, sweets, baked goods, and miscellaneous ( Supplementary Table S1).…”

“…The questionnaire comprised 65 questions, of which 57 were grouped as dairy, eggs and meat, fish and seafood, bread, cereals and starches, fruits, vegetables, fast foods, beverages, sweets, baked goods, and miscellaneous ( Supplementary Table S1). Food frequencies were measured on a six-point ordinal scale ranging from "never or less than once per month" to "4-6 times per day" 56 . We excluded data from women with more than ten dietary items missing and assumed an item was never consumed for missing data where ten or fewer items were missing 65 .…”