Relative validation of a food frequency questionnaire to assess dietary fatty acid intake / Validación relativa de un cuestionario de frecuencia de alimentos para evaluar la ingesta dietaria de ácido graso

OBJECTIVES: This study aimed to develop and validate a Food Frequency Questionnaire (FFQ) for assessing consumption of fatty acids among pregnant women. METHODS: Two lists of foods were created according to percent contribution of each nutrient estimated by three 24-hour recalls: a long and short version FFQ to estimate long-chain polyunsaturated fatty acids (LCPUFAs). Student paired t-test and Pearson correlation coefficients were used to verify the differences in mean consumption of nutrients from the FFQ and 24-hour recall. The concordance between the consumption values of the two methods was assessed using the Bland-Altman method and quartiles concordance. RESULTS: For the FFQ - long version, correlation values ranged from 0.33 (<0.05) to 0.62 (<0.01) for docosahexaenoic acid (DHA) and linoleic acid (LA), respectively. Eicosapentaenoic acid (EPA) and docosapentaenoic acid (DPA) were not correlated. Exact concordance ranged from 49.0% (energy) to 22.4% (EPA), and discordance ranged from 14.3% (DPA) to 2.0% (Saturated). The FFQ - short version had high correlations for LCPUFAs. Exact concordance ranged from 36.7% (n-3 LCPUFA) to 16.3% (DHA); and discordance from 12.2% (DPA) to 2.0% (arachidonic acid). Bland-Altman analysis showed good concordance for both versions. CONCLUSION: This nutrient-specific FFQ is a valid instrument to be used to estimate the level of consumption of fatty acids among pregnant women.

OBJETIVO: Este estudio tuvo como objetivo desarrollar y validar un cuestionario de frecuencia de consumo de alimentos para evaluar el consumo de ácidos grasos en gestantes. MÉTODOS: Dos listas de alimentos fueron creadas de acuerdo con la contribución porcentual de cada nutriente estimado por 3 recordatorios de 24 horas: CFC - versión larga y CFC - versión corta para estimar ácidos grasos poliinsaturados de cadena larga (AGPICL). La prueba de t pareada de Student y el coeficiente de correlación de Pearson se utilizaron para verificar las diferencias entre el consumo medio de nutrientes de del CFC y el recordatorio de 24 horas. La concordancia entre los valores de consumo de los dos métodos se evaluó mediante el método de Bland-Altman y la concordancia de cuartiles. RESULTADOS: En CFC - versión larga, los valores de correlación oscilaron entre 0.33 (<0.05) y 0.62 (<0.01) para ácido docosahexaenoico (DHA) y ácido linoleico (LA), respectivamente. Ácido eicosapentaenoico (EPA) y ácido docosapentaenoico (DPA) no presentaron correlación. La concordancia exacta varió de 49,0% (energía) a 22,4% (EPA), y la discordancia varió de 14,3% (DPA) a 2,0% (saturado). CFC: la versión corta mostró los mejores valores de correlaciones para los AGPICL. La concordancia exacta varió de 36,7 (n-3 LCPUFA) a 16,3% (DHA); y discordancia de 12,2% (DPA) a 2,0% (ácido araquidónico). El análisis de Bland-Altman mostró una buena concordancia para ambas versiones. CONCLUSIÓN: Este método CFC específico de nutrientes es un instrumento válido que se utiliza para estimar el nivel de consumo de ácidos grasos en mujeres gestantes.

Comparison of a Web-Based Frequency Questionnaire for Assessment of Beverage Intake with a Validated 7-Day Web-Diary from Danish Teenagers.

Aims: To compare beverage intake measured using a web-based quantitative beverage frequency questionnaire (BFQ) with a 7-day estimated beverage diary (WebDAS), and to evaluate the BFQ’s feasibility. Study Design: Cross-sectional comparison of the BFQ, which contained 37 beverage types including energy drinks and caffeinated beverages, with the WebDAS. Place and Duration of Study: Sample: Three 9th grade local authority school classes totalling 73 14-16-year-old students from a suburban area in Copenhagen were recruited. The study was carried out between September 2013 and November 2013. Methodology: First respondents completed the WebDAS at home, and after 2 weeks they completed the BFQ at school. McNemar’s test, the Wilcoxon signed rank test, Spearman’s rank correlation coefficients, a Bland-Altman plot, weighted Kappa statistics and percentages of exact agreement were used to compare the results of the two methods. Results: 49 (29 boys; 20 girls) had acceptable data from both the WebDAS, and the BFQ. The mean total beverage intake measured by the two methods differed significantly (BFQ: 1566 vs. WebDAS: 1231g/day, P<.01). The Spearman rank correlations were positive (r=.41-75) for all beverages including energy drinks, and significant for most beverages. Significant agreement for the numbers of consumers was observed between methods, except for soft drinks and chocolate. The mean (SD) difference was 335 (769)g/day, primarily due to an intake of water measured with BFQ almost twice as high as that measured with WebDAS. This was reflected in the Bland-Altman plot and in the percentages of exact agreement, which were lower for water than for other beverages (29% vs. 39-46%). Conclusion: The BFQ gave results comparable to a 7-day beverage diary (WebDAS) in 14-16-year-olds. With a few adjustments, especially with regard to portion sizes and entries for water, we believe the BFQ will be useful in large population-based studies for assessment of beverage intake.