Procedimentos metodológicos empregados em questionários de frequência alimentar elaborados no Brasil: uma revisão sistemática

Validation and calibration of the Food Consumption Frequency Questionnaire for pregnant women

BACKGROUND

Few food frequency questionnaires (FFQ) have been validated for pregnant women, particularly those in small- and medium-sized cities in different regions of Brazil.

OBJECTIVES

To validate and calibrate a semiquantitative FFQ for pregnant women.

DESIGN AND SETTING

The study was validated with a sample of 50 pregnant women (≥ 18 years) enrolled in Brazilian prenatal services.

METHODS

An FFQ and a 24-hour recall were used to evaluate dietary intake. Dietary variables were tested for normality and log-converted when asymmetrical. Pearson's Correlation Coefficient was used to validate the questionnaire. Linear regression was applied to extract calibration factors. All variables underlying the consumption analysis were adjusted for energy.

RESULTS

The mean age of the pregnant women was 26 years ± 6.2 years; 58% were in their first trimester, and 30% were identified as overweight/obese. The Pearson correlation analysis results indicated that the FFQ overestimated energy and nutrient intake, whose coefficients ranged from -0.15 (monounsaturated fat) to 0.50 (carbohydrate). Adjusting for energy reduced the mean values of intake coefficients, which now ranged from -0.33 (sodium) to 0.96 (folate). The calibration analysis results indicated variation in the coefficients from -0.23 (sodium) to 1.00 (folate). Calibration produced satisfactory coefficients for the FFQ compared with the reference standard for energy, macronutrients, monounsaturated fat, cholesterol, vitamins B12/C, folate, sodium, iron, and calcium.

CONCLUSIONS

After validating and calibrating tests, we observed that the FFQ was adequately accurate for assessing the food consumption of the pregnant women in this study.

Validation of the illustrated questionnaire on food consumption for Brazilian schoolchildren (QUACEB) for 6- to 10-year-old children

Introduction

Evaluating the food consumption of school-aged children is crucial to monitor their dietary habits, promote targeted interventions, and contribute public policies that aimed healthy eating. In this context, our objective was to develop and validate the Illustrated Questionnaire on Food Consumption for Brazilian Schoolchildren (QUACEB) of 6 to 10 years old, which is a self-reported illustrated recall.

Methods

Validity was obtained in four stages as follows: selection of foods, validation of items, validation of illustrations, and pretest. Foods were selected by considering the data from the main surveys that have been conducted with the Brazilian population and schoolchildren in recent years, the degree of food processing, and the main foods from each of the country's five macroregions. The content of the items was validated by comparing the children's and their parent's responses. For this, the questionnaire was published in an online format, and 6- to 10-year-old elementary schoolchildren were recruited using the snowball technique. The first part of the questionnaire was answered by the parent after the child's lunch, and the second was completed by the child the following day. Thirty-two parent and child dyads participated. Sensitivity, specificity, area under the curve (AUC), and kappa (k) tests were performed.

Results

Of the 30 foods presented on the questionnaire, 15 were reported as consumed. High sensitivity (mean of 88.5%), high specificity (average of 92.0%), substantial agreement (k = 0.78), low disagreement (6.2%), and AUC of 0.90 were found. The illustrations were validated in a focus group with fourth-grade children from a school chosen for convenience. The food illustrations were designed for children, who were asked to name the food. Eighteen children participated and verified that the images were representative of the foods. In the pretest, three schools were chosen for convenience that announced the link to the online questionnaire in WhatsApp groups of parents with students from first to fifth grade. Fifteen children answered the questionnaire and 86.7% (n = 13) judged it excellent or good.

Conclusion

Thus, the food consumption questionnaire is valid for elementary schoolchildren of 6 to 10 years old and can be applied in research to assess the dietary patterns of children in Brazil.

Consumo de alimentos preditores e protetores de risco cardiovacular por hipertensos do estado de Alagoas, Brasil

Resumo O presente artigo teve como objetivo avaliar o consumo de alimentos protetores e preditores de risco cardiovascular (CV) e sua relação com fatores de risco cardiovascular (FRCV) por hipertensos do estado de Alagoas. Estudo transversal, de base populacional, com 655 adultos, hipertensos, de ambos os sexos, estudados no período de 2013 a 2016. O consumo alimentar foi avaliado por um questionário de frequência alimentar validado com mensuração convertida em escores e os alimentos foram divididos em três grupos: I - processados/preditores de risco CV; II - ultraprocessados/maiores preditores de risco CV; III - alimentos in natura ou minimamente processados/protetores de risco CV. Foram também analisadas variáveis socioeconômicas, demográficas, bioquímicas, clínicas e antropométricas. Os escores de consumo dos grupos de alimentos I, II e III foram, respectivamente, 0,11; 0,13 e 0,24 (p = 0,001). O consumo de alimentos processados se correlacionou positivamente com o colesterol sérico elevado (p = 0,045) e negativamente com a idade (p = 0,001); já o de alimentos ultraprocessados correlacionou-se com o sedentarismo (p = 0,01). Assim, observou-se relação entre o consumo de alimentos preditores de risco CV com sedentarismo e colesterol elevado, refletindo a necessidade de ações de educação nutricional.

Healthy Eating Index: adaptation for children aged 1 to 2 years

The goal was to adapt the Healthy Eating Index (HEI) to the US Dietary Guidelines for Brazilian children. Cross-sectional study conducted in a population-based sample of 1185 children 13-35 months old of São Luís municipality (MA). A 24-hour dietary recall Survey measured the food consumption and set the intrapersonal variance diet. We evaluated the construct validity by Principal Component Analysis and the Pearson correlation coefficient to see whether the index measures the quality of independent dietary energy consumed. We evaluated the reliability for the analysis of internal consistency, by calculating the alpha coefficient Conbrach and the correlations between each component and the total score. The correlations between the scores of components and energy were low (r ≤ 0.29). Four factors with eigenvalues > 1 were retained with cumulative variance of 58%. Cronbach's alpha was 0.48. The variety of the diet (r = 0.77) and vegetables and legumes (r = 0.60) had higher positive correlations with the total score (p < 0.05). The average of the HEI was 74.8 (± 13.2) points to 58.7% of children with diets that needed improvement. The adapted HEI proved to be valid to assess the overall quality of the diet of children.

A systematic review of reviews identifying UK validated dietary assessment tools for inclusion on an interactive guided website for researchers: www.nutritools.org

Background: Health researchers may struggle to choose suitable validated dietary assessment tools (DATs) for their target population. The aim of this review was to identify and collate information on validated UK DATs and validation studies for inclusion on a website to support researchers to choose appropriate DATs.Design: A systematic review of reviews of DATs was undertaken. DATs validated in UK populations were extracted from the studies identified. A searchable website was designed to display these data. Additionally, mean differences and limits of agreement between test and comparison methods were summarized by a method, weighting by sample size.Results: Over 900 validation results covering 5 life stages, 18 nutrients, 6 dietary assessment methods, and 9 validation method types were extracted from 63 validated DATs which were identified from 68 reviews. These were incorporated into www.nutritools.org. Limits of agreement were determined for about half of validations. Thirty four DATs were FFQs. Only 17 DATs were validated against biomarkers, and only 19 DATs were validated in infant/children/adolescents.Conclusions: The interactive www.nutritools.org website holds extensive validation data identified from this review and can be used to guide researchers to critically compare and choose a suitable DAT for their research question, leading to improvement of nutritional epidemiology research.

Validade relativa de questionário de frequência alimentar com suporte de imagens

Resumo O objetivo do presente estudo foi avaliar a validade relativa de questionário de frequência alimentar (QFA), desenvolvido para adolescentes. O estudo envolveu amostra de 106 adolescentes (57% meninas) de 11 a 18 anos de idade. O QFA foi aplicado em entrevistas pessoais com o suporte de fotografias dos 93 itens alimentares. As médias deatenuadas da ingestão de energia e nutrientes de três recordatórios de 24 horas (R24h) foram consideradas como referência e foram comparadas com aquelas estimadas pelo QFA com o uso do coeficiente de correlação de Spearman, kappa ponderado para a concordância da categorização em quartis, e limites de concordância de Bland-Altman. Os coeficientes de correlação variaram de 0,27 a 0,49 (média = 0,43), o kappa ponderado variou de 0,28 a 0,51 (média = 0,40), e a concordância média estimada variou de 109 a 159% (média = 130%). Aproximadamente 30% das estimativas foram classificados de forma exata em um mesmo quartil e cerca de 90% em quartis iguais ou adjacentes. Resultados obtidos com a aplicação do QFA com o suporte de fotografias foram mais favoráveis do que os observados para o questionário isoladamente. O QFA foi considerado apropriado para categorizar adolescentes segundo gradientes de consumo energia e nutrientes.

Intake of antioxidant nutrients and coefficients of variation in pregnant women with preeclampsia

INTRODUCTION AND OBJECTIVE

Oxidative stress appears to play a critical role in the pathogenesis of preeclampsia. Evidence suggests that adequate intake of antioxidants can modulate this condition. The objective of this study was to assess the intake of antioxidant nutrients and coefficients of variation in pregnant women with preeclampsia.

METHODS

In a cross-sectional study in the public health network of the city of Maceió, Brazil, a dietary survey was performed consisting of 24-hour food recalls, with subsequent adjustment of nutrients using the estimated average requirement as the cutoff point, and a questionnaire on frequency of consumption of antioxidants.

RESULTS

We studied 90 pregnant women with preeclampsia (PWP) and 90 pregnant women without preeclampsia (PWoP) with mean ages of 25.8±6.7 years and 24.1±6.2 years (p=0.519), respectively. A low mean intake of antioxidants (vitamin A, selenium, zinc and copper) was observed in both PWP and PWoP, although intakes of vitamin A (p=0.045) and selenium (p=0.008) were higher in PWoP. In addition, we observed high coefficients of variation in nutrient intakes in both groups, which were higher for vitamin C (p<0.001), vitamin A (p=0.006) and copper (p=0.005) in PWP.

CONCLUSIONS

Consumption of antioxidant nutrients by pregnant women with preeclampsia is inadequate, with considerable daily variations in intake, which points to a need for nutrition education strategies aimed at improving intakes, because diet is without doubt a key factor in the modulation of oxidative stress caused by preeclampsia.

Comparison of a short version of the Food Frequency Questionnaire with its long version--a cross-sectional analysis in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

CONTEXT AND OBJECTIVE

The food frequency questionnaire (FFQ) is the preferred instrument for obtaining dietary information in epidemiological studies. A short form of the FFQ was compared with the original version that was used in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), and also with three 24-hour dietary recalls.

DESIGN AND SETTING

Cross-sectional study carried out in six Brazilian state capitals.

METHODS

Multiple linear regression was used to reduce the original food and drink list of the FFQ, which had contained 114 food items. The frequency of consumption and nutritional composition of the foods were also taken into consideration. To assess the validity of the shortened FFQ, the energy and nutrients values of the 24-hour dietary recalls were deattenuated and log-transformed.

RESULTS

The list of the FFQ of ELSA-Brasil was reduced to 76 food items. The intraclass correlation coefficients in the validation study ranged from 0.17 (selenium) to 0.66 (calcium).

CONCLUSIONS

The number of items was reduced by 33%, while still maintaining relatively good capacity to measure energy and selected nutrients.

[Reproducibility, relative validity, and calibration of a food-frequency questionnaire for adults in Greater Metropolitan Porto Alegre, Rio Grande do Sul State, Brazil]

This study tested the relative validity and estimated calibration factors of a food-frequency questionnaire (FFQ) with 120 food items in 128 adults. We applied one FFQ and three 24h recalls. Validity was tested by the Bland-Altman method, intraclass correlation coefficient (ICC), classification in quartile categorization, and weighted kappa. Calibration factors were estimated by linear regression, with 24h recall of food intake as the dependent variable and the FFQ values as the independent variable. FFQ underestimated the nutrient intake when compared to 24h recall. The energy-adjusted and de-attenuated ICC ranged from 0.19 (zinc) to 0.82 (calcium). 37% of subjects were classified in the same quartile, with mean kappa of 0.28 (zinc: 0.08; calcium: 0.49). The highest calibration factors were 0.48 (calcium), 0.47 (potassium), and 0.44 (carbohydrates), and the lowest was 0.10 (retinol). FFQ showed satisfactory relative validity and calibrated energy and nutrient intake values similar to 24h recall.

Avaliação do consumo alimentar de crianças brasileiras assistidas em creches: uma revisão sistemática

Objetivos: levantar evidências sobre o perfil do consumo alimentar de crianças brasileiras assistidas em creches. Métodos: foi realizada uma busca por estudos observacionais nas bases de dados PubMed, LILACS e SciELO. Foram selecionados artigos publicados entre 1990 e 2013, utilizando os termos “food consumption” AND “child day care centers”. Resultados: foram identificados 58 artigos, dos quais 21 artigos foram considerados relevantes para o presente trabalho: 18 estudos transversais e três longitudinais. A sistematização dos estudos destaca: i) a concentração geográfica no Sudeste do país; ii) a apropriação da pesagem direta de alimentos e dos valores de referência das Dietary Reference Intakes na avaliação do consumo de alimentos; iii) um panorama preliminar, com ênfase no Sudeste, do consumo deficitário de legumes, frutas e vegetais, e da inadequação da ingestão dietética de ferro; iv) a restrição dos resultados à ingestão média devido à insuficiência do uso de métodos apropriados ao estabelecimento de padrões alimentares. Conclusões: apesar da escassez e dispersão espaço-temporal dos estudos, as semelhanças metodológicas possibilitam sugerir um panorama em que predomina a ingestão dietética deficitária do grupo de frutas, legumes e verduras, e de alimentos ricos em ferro; bem como a ingestão excessiva de alimentos protéicos e de alto teor de sódio.