Validity and reproducibility of a food frequency questionnaire to assess food group intake in adolescents

Abstract

The objective of this study was to assess the validity and reproducibility of a food frequency questionnaire to assess intake of the food groups included in the food guide pyramid for adolescents (FFQ-FP). The final version of the FFQ-FP consisted of 50 food items. The study was carried out with a sample of 109 adolescents over a period of four months. A 24hr recall (24hr) was conducted four times and the FFQ-FP was conducted twice. Validity was determined by comparing the second FFQ-FP and the mean of the four 24hrs, while reproducibility was verified by comparing the results of the two FFQ-FPs. Statistical analysis was carried out using medians, standard deviations, Pearson and intraclass correlations and Kappa statistics to assess concordance. Best results were achieved for the rice (including bread, grains and starches), meats and sugars groups. Weakest correlation was observed for the variable vitamin C. The validity and reproducibility of the FFQ-FP was satisfactory for most variables.

Relative validity of a web-based food frequency questionnaire for Danish adolescents

“…They may also be less motivated to record their dietary intake and have increased focus on body image, which seems to affect the accuracy of their self-report [ 39 ]. These characteristics may result in high within-person day-to-day variability among adolescents which seems to attenuate correlation coefficients [ 9 , 14 ]. This was in particular evident for dairy, energy intake, MUFA, and calcium where Spearman’s correlation coefficient increased after de-attenuation which was also reported in the study by Rockett et al [ 13 ].…”

“…Although a 24HR relies on memory, as does the FFQ, 24HRs are common in relative validity studies using FFQs among adolescents [ 11 , 12 ]. FFQs are in general considered suitable or valid for ranking adolescents at group level with correlation coefficients ranging from 0.2 to 0.8 [ 11 – 14 ]. In terms of what can be considered as acceptable validity in such studies, Cade et al suggested a cut-off of 0.40 as an acceptable correlation [ 15 ].…”

Dietary intake and meal frequency of Brazilian girls attending a school-based randomized controlled trial

“…Dietary outcomes were the energy contributed from the eight food groups and the total energy intake. Dietary intake was assessed using the Food Frequency Questionnaire based on the Food Pyramid (FFQ-FP), which was previously validated and evaluated for reliability in adolescents from public schools of São Paulo, Brazil (mean [standard deviation] 16 [0.99] years) (Martinez et al, 2013).…”

The web-based ASSO-food frequency questionnaire for adolescents: relative and absolute reproducibility assessment

“…Although gathered measures could be biased by the self-reporting method of the ASSO-FFQ, there is evidence that children are more accurate reporters than their parents [ 26 ]. Moreover, as suggested previously [ 27 ], the second ASSO-FFQ was administered after one month, an interval that was retained reasonable to avoid change in diet due to food seasonality; other studies considered a longer time interval [ 8 , 22 ].…”

“…Different FFQs have been validated and have been shown to be reliable [ 4 , 8 – 12 ], but the need of a web-based, more user-friendly, fast and cost-effective tool has been recently highlighted [ 13 ]. To this purpose, the ASSO-FFQ has been developed within the Adolescents and Surveillance System for the Obesity prevention (ASSO) Project, financially supported by the Italian Ministry of Health.…”