Validação de Questionários de Freqüência Alimentar - QFA: considerações metodológicas

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.

Dietary patterns and socioeconomic, demographic, and health-related behaviors during pregnancy. A cross-sectional study

BACKGROUND

The identification and understanding of dietary factors and other characteristics that influence gestational weight gain can contribute to the formulation of strategies to promote healthy eating habits before and during pregnancy.

OBJECTIVE

To investigate the association between dietary patterns, sociodemographic and obstetric characteristics, and health-related behaviors in pregnant women.

DESIGN AND SETTING

A cross-sectional study was conducted on women undergoing prenatal care in the Unified Health System of Colombo, Paraná, Brazil, from February 2018 to September 2019.

METHOD

A weekly food frequency questionnaire was administered, and dietary patterns were identified through factor analysis. Median regression models were constructed to identify the associations between dietary pattern scores and variables.

RESULTS

Complete data were obtained from 495 pregnant women. Three dietary patterns were identified: 1) "healthy," with higher factor loadings for the weekly consumption of raw vegetables, cooked vegetables, and fresh fruits; 2) "Western," including soft drinks or artificial juice, candies, milk, and dairy products, and processed cold meat; and 3) "traditional," beans and meat. Pregnant women aged 30 years or older (coefficient [Coef.] 0.86, 95% confidence interval [CI] 0.38-1.33) with moderate/intense physical activity (Coef. 0.32, 95% CI 0.02-0.62) had higher adherence to the "healthy" pattern. Adolescents and smokers adhered more to the "traditional" pattern (Coef. 0.17, 95% CI 0.01-0.33).

CONCLUSION

Age, smoking status, and physical activity were associated with dietary patterns in pregnant women.

Development and Validation of a Food Frequency Questionnaire to Assess Potassium Intake of Patients on Hemodialysis

OBJECTIVE

To develop and to validate a food frequency questionnaire (FFQ) to assess potassium intake of patients on hemodialysis.

METHODS

This is a cross-sectional study that included 41 patients in the FFQ development step and 53 patients in the FFQ validation step. In the FFQ development step, the patients completed a 3-day food record (used as a reference method). Total potassium intake and potassium from each food item were calculated. Food items that contributed up to 90% of the total potassium intake were considered to be included in the FFQ food list. Then the FFQ was applied in person through the google-forms platform. The result of potassium intake obtained by the FFQ was compared with that obtained by the 3-day food record.

RESULTS

A total of 94 patients were included: 53.2% women; age 55.7 ± 15.0 years; 47.9% had diabetes; body mass index 25.0 ± 4.5 kg/m²; and dialysis vintage 34.5 (17.0-68.2) months. Demographic, clinical, and laboratory parameters did not differ between the development and validation groups. From the 255 registered food items, 85 comprised the FFQ. The standardized Cronbach's alpha obtained was 0.71. No difference was found between the potassium intake obtained by the FFQ and by the 3-day food record (1,438.5 ± 659.4 mg/d vs. 1,464.8 ± 529.4 mg/d; P = .753, respectively) with an intraclass correlation coefficient of 0.66 (P = .001). No systematic bias or proportionality bias between the methods was observed in the Bland-Altman graphical analysis.

CONCLUSION

The quantitative FFQ presented strong relative validity and may constitute a practical tool in the analysis of potassium intake of patients on hemodialysis.

Quality of Life among Patients with Acute Coronary Syndromes Receiving Care from Public and Private Health Care Systems in Brazil

(1) Background: Quality of life (QOL) is used as a health indicator to assess the effectiveness and impact of therapies in certain groups of patients. This study aimed to analyze the QOL of patients with acute coronary syndrome (ACS) who received medical treatment by a public or private health care system. (2) Methods: This observational, prospective, longitudinal study was carried out in four referral hospitals providing cardiology services in Sergipe, Brazil. QoL was evaluated using the Medical Outcomes Study 36-Item Short-Form Health Survey. The volunteers were divided into two groups (public or private health care group) according to the type of health care provided. Multiple linear regression models were used to evaluate QoL at 180 days after ACS. (3) Results: A total of 581 patients were eligible, including 44.1% and 55.9% for public and private health care, respectively. At 180 days after ACS, the public health care group had lower QoL scores for all domains (functional capacity, physical aspects, pain, general health status, vitality, social condition, emotional profile, and health) (p < 0.05) than the private group. The highest QoL level was associated with male sex (p < 0.05) and adherence to physical activity (p ≤ 0.003) for all assessed domains. (4) Conclusions: This shows that social factors and health status disparities influence QoL after ACS in Sergipe.

Relative validity and reproducibility of food frequency questionnaire for individuals on hemodialysis (NUGE-HD study)

INTRODUCTION

Adequate assessment of food intake is essential to establish the magnitude and direction of the relationship of food, nutrients, and bioactive compounds with clinical outcomes of individuals in hemodialysis. We evaluated the relative validity and reproducibility of a specific food frequency questionnaire for individuals on hemodialysis (FFQ-HD).

METHODS

Eighty-two participants (57.3% male, 57.5 ± 14.4 years) from the open cohort Nutrition and Genetics in Hemodialysis Outcomes participated in this study. The relative validity of the FFQ-HD was assessed using the mean of two 24-h food recall (24hR) adjusted for within-subject variability as a reference method. We also performed Pearson correlations, and agreement between tertile, kappa statistics, and Bland-Altman scatter plots were validated. Reproducibility was assessed after 1 year using intraclass correlation coefficient (ICC).

FINDINGS

Daily energy intake was not different between FFQ-HD and 24hR (mean difference of 50.1 kcal). Intake of protein, linolenic acid, fiber, phosphorus, potassium, sodium, calcium, and sugar showed a moderate correlation (r between 0.4 and 0.5) among instruments, while mean correlation coefficient was r = 0.38 to food group intake. Bland-Altman plots showed good agreement for micronutrients, phosphorus, sodium, and potassium and for the groups "flour, bread, and pasta" and "processed, canned meat, salts, and seasonings". The reproducibility of FFQ-HD for nutrients and food groups was satisfactory, reaching a maximum ICC of 0.72 and 0.59, respectively.

DISCUSSION

The FFQ-HD showed moderate validity and reproducibility for calories, nutrients, and food groups of clinical and nutritional interest for HD subjects so that it can be a useful tool in epidemiological studies in this population.

Online Food Frequency Questionnaire From the Cohort of Universities of Minas Gerais (CUME Project, Brazil): Construction, Validity, and Reproducibility

Background: The Food Frequency Questionnaire (FFQ) is usually used in epidemiological studies to assess food consumption. However, the FFQ must have good accuracy, requiring its validation and reproducibility for the target population. Thus, this study aimed to describe the construction of the online Food Frequency Questionnaire (oFFQ) used at the Cohort of Universities of Minas Gerais (CUME project, Brazil) and evaluate its validity and reproducibility.

Methods: The oFFQ was answered two times in 1 year (March/August 2018—March/April 2019; n = 108 participants—reproducibility), and four 24-h dietary recalls (24hRs) were applied in two seasons of the southern hemisphere [two 24hRs in autumn (March/June 2018) and two 24hRs in winter (August/September 2018); n = 146 participants—validity]. To assess the validity and reproducibility, the intraclass correlation coefficients (ICCs) were estimated.

Results: The oFFQ had 144 food items separated into eight groups (dairy products; meat and fish; cereals and legumes; fruits; vegetables; fats and oils; drinks; other foods). In assessing the validity, ICCs for energy and macronutrients were considered moderate, ranging from 0.41 (energy) to 0.59 (protein), while the ICCs for micronutrients were considered low to moderate, ranging from 0.25 (fibers) to 0.65 (vitamin B6). Regarding reproducibility assessment, ICCs for energy and all the assessed items were considered moderate to excellent, ranging from 0.60 (vegetables) to 0.91 (vitamin E and retinol).

Conclusions: The self-reported oFFQ had satisfactory validity and reproducibility. So, it can be used to analyze the association between food consumption and chronic diseases in the participants of the Cohort of Universities of Minas Gerais (CUME project—Brazil).

Green-banana biomass consumption by diabetic patients improves plasma low-density lipoprotein particle functionality

The aim of this study was to investigate the effects of 6-months consumption of green-banana biomass on the LDL particle functionality in subjects with type 2 diabetes. Subjects (n = 39, mean age 65 years old) of both sexes with diabetes (HbA1c ≥ 6·5%) were randomized to receive nutritional support plus green-banana biomass (40 g) (n = 21) or diet alone (n = 18) for 6-months. Non-linear optical responses of LDL solutions from these participants were studied by Z-scan technique. UV-visible spectrophotometer was used to measure the absorbance of the LDL samples. Small Angle X-ray Scattering and Dynamic Light Scattering experiments were used to look for any structural changes in LDL samples and to determine their size distribution. The Lipoprint test was used to determine the LDL sub-fractions in terms of distribution and size. Consumption of green-banana biomass, reduced total- (p = 0.010), non-HDL-cholesterol (p = 0.043), glucose (p = 0.028) and HbA1c (p = 0.0007), and also improved the protection of the LDL particle against oxidation, by the increase in carotenoids content in the particles (p = 0.007). This higher protection against modifications may decrease the risk of developing cardiovascular disease. These benefits of the green-banana biomass encourage the use of resistant starches with potential clinical applications in individuals with pre-diabetes and diabetes.

Beneficial effects of green banana biomass consumption in patients with pre-diabetes and type 2 diabetes: a randomised controlled trial

Diabetes mellitus is a global epidemic, characterised as a heterogeneous group of metabolic disorders associated with high risk of CVD. Green banana biomass, which is composed of resistant starches (RS) and cannot be hydrolysed by amylases, delays gastric emptying and modulates insulin sensitivity, thus contributing to improve metabolic disorders. The aim of the present study was to investigate the effects of consumption of RS from green banana biomass on body composition, fasting plasma glucose, glycated Hb (HbA1c) and homeostasis model assessment of insulin resistance in subjects with pre-diabetes or type 2 diabetes on top of treatment. Middle-aged subjects (n113) of both sexes with pre-diabetes (HbA1c: 5·7–6·4 %) or diabetes (HbA1c ≥ 6·5 %) were randomised to receive nutritional support plus green banana biomass (40 g) (RS: approximately 4·5 g, G1,n62) or diet alone (G2,n51) for 24 weeks. Body composition, biochemical analyses and dietary intake were evaluated at the beginning and end of the study. In the experimental group (G1), consumption of RS was associated with reduction in HbA1c (P= 0·0001), fasting glucose (P= 0·021), diastolic blood pressure (P= 0·010), body weight (P= 0·002), BMI (P= 0·006), waist and hip circumferences (P< 0·01), fat mass percentage (P= 0·001) and increase in lean mass percentage (P= 0·011). In controls (G2), reductions were observed in waist and hip circumferences (P< 0·01), HbA1c (P= 0·002) and high-density lipoprotein-cholesterol (P= 0·020). In pre-diabetes or diabetes, non-significant differences were observed in the percentage reduction in HbA1c and fasting glucose in exploratory analyses. Our results indicate that the consumption of bioactive starches is a good dietary strategy to improve metabolic control and body composition.

Consumption of ultra-processed food and obesity: cross sectional results from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) cohort (2008-2010)

OBJECTIVE

To verify if the intake of ultra-processed foods is associated with higher BMI and waist circumference (WC) among participants of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) cohort.

DESIGN

Cross-sectional analysis of the ELSA-Brasil baseline (2008-2010). Dietary information obtained through an FFQ was classified according to characteristics of food processing (NOVA) and used to estimate the percentage energy contribution from ultra-processed foods (i.e. industrial formulations, elaborated from food processing, synthetic constituents and food additives) to individuals' total energy intake. BMI and WC and their respective cut-off points served as response variables. Associations were estimated through linear and multinomial logistic regression models, after adjusting for confounders and total energy intake.

SETTING

Six Brazilian capital cities, 2008-2010.

SUBJECTS

Active and retired civil servants, aged 35-64 years, from universities and research organizations (n 8977).

RESULTS

Ultra-processed foods accounted for 22·7 % of total energy intake. After adjustments, individuals in the fourth quartile of percentage energy contribution from ultra-processed foods presented (β; 95 % CI) a higher BMI (0·80; CI 0·53, 1·07 kg/m2) and WC (1·71; 1·02, 2·40 cm), and higher chances (OR; 95 % CI) of being overweight (1·31; 1·13, 1·51), obese (1·41; 1·18, 1·69) and having significantly increased WC (1·41; 1·20, 1·66), compared with those in the first quartile. All associations suggest a dose-response gradient.

CONCLUSIONS

Results indicate the existence of associations between greater energy contribution from ultra-processed foods and higher BMI and WC, which are independent of total energy intake. These findings corroborate public policies designed to reduce the intake of this type of food.

Consumption of ultra-processed foods and socioeconomic position: a cross-sectional analysis of the Brazilian Longitudinal Study of Adult Health

The objective of the study was to estimate the contribution of ultra-processed foods to total caloric intake and investigate whether it differs according to socioeconomic position. We analyzed baseline data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil 2008-2010; N = 14.378) and data on dietary intake using a food frequency questionnaire, assigning it into three categories: unprocessed or minimally processed foods and processed culinary ingredients, processed foods, and ultra-processed foods. We measured the associations between socioeconomic position (education, per capita household income, and occupational social class) and the percentage of caloric contribution of ultra-processed foods, using generalized linear regression models adjusted for age and sex. Unprocessed or minimally processed foods and processed culinary ingredients contributed to 65.7% of the total caloric intake, followed by ultra-processed foods (22.7%). After adjustments, the percentage of caloric contribution of ultra-processed foods was 20% lower among participants with incomplete elementary school when compared to postgraduates. Compared to individuals from upper income classes, the caloric contribution of ultra-processed foods was 10%, 15% and 20% lower among the ones from the three lowest income, respectively. The caloric contribution of ultra-processed foods was also 7%, 12%, 12%, and 17% lower among participants in the lowest occupational social class compared to those from high social classes. Results suggest that the caloric contribution of ultra-processed foods is higher among individuals from high socioeconomic positions with a dose-response relationship for the associations.

[Food Frequency Questionnaire developed and validated for the Brazilian population: a review of the literature]

Assessing food intake is a challenge for researchers given the inherent complexity of the issue. One of the methods used in epidemiological studies is the Food Frequency Questionnaire (FFQ). The scope of this paper was to identify studies that developed and/or validated the FFQ in Brazil, analyzing the methods used and the main results of the validation. The PubMed, LILACS and SciELO databases were researched for studies published prior to 2013 on the development and validation of the FFQ in Brazil. These studies were analyzed according to: i) the main methodological characteristics of the elaboration/validation process of the questionnaires; ii) the key results related to validation. Forty-one studies were assessed: 6 on the development of the FFQ; 18 on the development and validation of the FFQ; 17 on the validation of the FFQ. There were inter-regional differences in the publications and methodological differences in the elaboration and validation of the FFQ. Adults and adolescents were the groups most covered for the validation of the FFQ, though specific studies for children < 5 years of age were not found. The methodological rigor and statistical results guarantee the suitability of the validation of the FFQ for the target populations, with high correlations for energy, carbohydrates, fibers, calcium and vitamin C.

ASSOCIATION OF THE NUTRITIONAL PROFILE WITH HISTOLOGICAL FINDINGS OF PATIENTS WITH GENOTYPE 1 CHRONIC HEPATITIS C INFECTION

BACKGROUND

Different factors are responsible for the progression of hepatic fibrosis in chronic infection with hepatitis C virus, but the role of nutritional factors in the progression of the disease is not clearly defined. This study aimed to evaluate the nutritional status and dietary profile among patients with chronic hepatitis C who were candidates for treatment and its association with histopathological features.

METHODS

A crossectional study was conducted on treatment-naïve patients with chronic hepatitis C genotype 1, between 2011 and 2013. The following assessments were performed before treatment: liver biopsy, anthropometric measurements and qualitative/quantitative analysis of food intake.

RESULTS

Seventy patients were studied. The majority of patients was classified as obese (34%) or overweight (20%) according to body mass index [BMI] and as at risk for cardiovascular diseases by waist circumference (79%). Unhealthy food intake was presented by 59% according to qualitative parameters and several patients showed an insufficient intake of calories (59%), excessive intake of protein (36%) and of saturated fat (63%), according to quantitative analysis. With respect to histology, 68% presented activity grade ≥2, 65% had steatosis and 25% exhibited fibrosis stage >2. Comparative analysis between anthropometric parameters and histological features showed that elevated waist circumference was the only variable associated to hepatic steatosis ( P =0.05). There was no association between qualitative and quantitative food intake parameters with histological findings.

CONCLUSION

In this study, most of the patients with hepatitis C presented inadequate qualitative food intake and excessive consumption of saturated fat; in addition, excess of abdominal fat was associated to hepatic steatosis. Therefore, nutritional guidance should be implemented prior to treatment in patients with chronic hepatitis C, in order to avoid nutritional disorders and negative impact on the management of patients.

Validation of a food frequency questionnaire designed for adolescents in Salvador, Bahia, Brazil

Objective: This study assessed the validity of a Food Frequency Questionnaire used to assess food intake in adolescents in Salvador, Bahia, Brazil. Methods: Seventy adolescents enrolled in public schools aged 11 to 17 years participated in this study. The dietary intake of the adolescents was assessed using the Food Frequency Questionnaire and the mean value of three-day food record, used as the reference method. The mean (and standard deviation) energy and nutrient intakes estimated from the Food Frequency Questionnaire and food records were calculated. The paired Student's t test was used to determine differences between the data. Results: Pearson's correlation coefficient and Kappa statistics were used to measure the strength of the association between the two instruments. There was variation in the crude unadjusted (r=0.61-0.73) and deattenuated (r=0.33-0.99) Pearson correlation coefficients. After adjusting for energy, the crude and deattenuated coefficients ranged from r=0.53-0.81 and r=0.27-0.99, respectively. The intake of energy and most nutrients were found to be adequate, except for fiber (r=0.27) and calcium (r=0.33), which showed a weak correlation. Kappa statistics showed good correlation between all values varying from r=0.47 to 0.73. Conclusion: It is considered that an average r value greater than 0.40 indicates a good correlation, the results obtained indicate the good ability of the Food Frequency Questionnaire to assess individuals according to their usual intake of most nutrients.

Validation of a quantitative food frequency questionnaire developed to under graduate students

A validity test of a Food Frequency Questionnaire was carried out using 50 students of health occupation in São Paulo, Brazil. Therefore, a three day dietary record was used as reference method and variables such as energy, macronutrients and dietary fiber were analyzed. The accordance between the Food Frequency Questionnaire and average data from dietary record was tested with kappa statistics and intra-class correlation coefficients (ICC). Limits of agreement were estimated by the Bland-Altman's method. Better results were found for calories (ICC 0.43; 95%CI 0.17 - 0.63) and non-energy-adjusted nutrients, except dietary fiber (ICC 0.34; 95%CI 0.07 - 0.56). The percentage of individuals classified in the same category of consumption was nearly half (49.8%), while only 16% of them were classified in opposite categories. With the exception of lipids, other analyzed variables tended to be overestimated by the Food Frequency Questionnaire. The Food Frequency Questionnaire is recommended as a method of assessing food intake of university students in studies which focus on calorie estimates and also intend to classify groups into intake categories.

Fatores associados ao consumo de bebidas açucaradas entre pré-escolares brasileiros: inquérito nacional de 2006

ResumoO crescente consumo de bebidas açucaradas como os refrigerantes ou sucos artificiais está associado à prevalência de obesidade no Brasil e no mundo. Este estudo se propõe a conhecer a frequência de consumo destas bebidas entre crianças brasileiras de 24 a 59 meses e investigar associações com variáveis demográficas, socioeconômicas e nutricionais. Utilizando dados da Pesquisa Nacional de Demografia e Saúde da Criança e da Mulher − 2006, o padrão alimentar foi obtido com o questionário de frequência de alimentos e bebidas nos sete dias anteriores à data da entrevista e a antropometria usou medidas de peso e de estatura das crianças. Entre os pré-escolares, 37,3% consumiram refrigerantes e sucos artificiais 4 dias ou mais por semana. Os fatores que apresentaram associação estatisticamente significante com consumo frequente de BA foram residir em regiões de maior desenvolvimento econômico do país, em áreas urbanas, pertencer ao estrato de maior poder aquisitivo, mães que assistiam TV regularmente e excesso de peso da criança, estavam associados ao consumo de refrigerantes e sucos artificiais em 4 ou mais dias por semana. Novos estudos são necessários para a compreensão da real contribuição das bebidas açucaradas na epidemia de obesidade infantil.

[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.

Consumo alimentar e condições de trabalho no corte manual de cana de açúcar no estado de São Paulo1

Objetivo Descrever as condições de trabalho e aspectos relacionados à alimentação do trabalhador no corte manual de cana para contribuir para desenvolver políticas públicas de vigilância e atenção integral em Saúde do Trabalhador. Métodos Foram utilizados a observação direta do trabalho no campo em colheita no estado de São Paulo e aplicado questionário semi-estruturado a um grupo de 40 cortadores manuais de cana migrantes procedentes do estado do Ceará, durante 15 dias da safra 2007/2008. Aspectos sócio-demográficos, consumo de água, reposição eletrolítica, alimentação e aspectos culturais, pausas, dores e a jornada de trabalho foram registrados. Resultados Os trabalhadores ingerem de 5 a 10 litros de água/dia e a diluição dos repositores eletrolíticos foi inferior à adequada. A alimentação durante a safra não garantia a segurança alimentar e nutricional. A alimentação foi monótona, conservada e consumida em temperatura inadequada, e incompatível com os hábitos culturais, gerando desperdício e redução do consumo alimentar. Os trabalhadores relataram dores e câimbras no decorrer da jornada. As pausas para descanso foram insuficientes. O pagamento pela quantidade de produção, o processo de trabalho e as práticas de pagamento foram considerados determinantes da situação de precariedade ampla a que estes trabalhadores estavam submetidos. O trabalho no corte manual de cana é extenuante e o pagamento por produção pode ser um agravante para a saúde, pois implica na redução das pausas para descanso. A alimentação e hidratação corretas poderiam minimizar o desgaste e as dores durante o trabalho.

Validity and reproducibility of a food frequency questionnaire for adults of São Paulo, Brazil

OBJECTIVES: To assess the validity and reproducibility of a food frequency questionnaire developed for estimating the food consumption of adults in São Paulo, Brazil, based population study. METHODS: A sample of individuals aged above 20 years, of both genders, living in São Paulo, was used for the validation study (n = 77) and reproducibility study (n = 74) of the food frequency questionnaire. To verify the validity and reproducibility of energy and 19 nutrients were applied two food frequency questionnaires (60 items) and three 24-hour dietary recalls (24HR - reference method). The validity was verified by Spearman correlation coefficient (crude and de-attenuated) and weighted Kappa, and reproducibility by intraclass correlation coefficients and weighted kappa. RESULTS: In analyzes of validity de-attenuated correlation coefficients ranged from 0.21 (carbohydrate) to 0.74 (energy), and weighted kappa exceeded 0.40 for 30% of the nutrients. Polyunsaturated fat and folate did not show significant correlation and weighted kappa. In reproducibility correlation coefficients ranged from 0.36 (polyunsaturated fat) to 0.69 (calcium), and weighted kappa exceeded 0.40 for 80% of the nutrients. CONCLUSION: The food frequency questionnaire analyzed has good validity and reproducibility for estimating the food consumption of adults in São Paulo compared to the reference method, so it is an appropriate instrument to be used in epidemiological studies on similar populations. Estimates of polyunsaturated fat and folate should be interpreted with caution.

Reproducibility and validity of a quantitative FFQ designed for patients with type 2 diabetes mellitus from southern Brazil

OBJECTIVE

To evaluate the reproducibility and validity of a previously constructed FFQ to assess the usual diet of patients with type 2 diabetes mellitus (T2DM).

DESIGN

Cross-sectional survey using two quantitative FFQ (1-month interval) supported by a food photograph portfolio, a 3 d weighed diet record (WDR) and urinary N output measurement (as a biomarker of protein intake).

SETTING

Group of Nutrition in Endocrinology, southern Brazil.

SUBJECTS

Out-patients with T2DM.

RESULTS

From a total of 104 eligible T2DM patients, eighty-eight were included in the evaluation of FFQ reproducibility and seventy-two provided data for the validity study. The intakes estimated from the two FFQ did not differ (P > 0·05) and the correlation coefficients were significant (P < 0·01) for energy and nutrients, ranging from 0·451 (soluble fibre) to 0·936 (PUFA). Regarding the validity evaluation, data from the FFQ were higher than those from the WDR for total (28·3%), soluble (27·4%) and insoluble fibres (29·1%), and SFA (13·5%), MUFA (11·1 %) and total lipids (9·2%; all P < 0·05). There were significant correlation coefficients between the FFQ and WDR for most nutrients, when adjusted for energy intake and de-attenuated. Also, the Bland-Altman plots between the FFQ and WDR for energy and macronutrient intakes showed that the FFQ may be used as alternative method to the WDR. The validity coefficient (using the method of triads) for the FFQ protein intake was 0·522 (95% CI 0·414, 0·597).

CONCLUSIONS

This quantitative FFQ was valid and precise to assess the usual diet of patients with T2DM, according to its validity and reproducibility.

Validade relativa de indicadores de práticas alimentares da Pesquisa Nacional de Saúde do Escolar entre adolescentes do Rio de Janeiro, Brasil

Avaliou-se a validade relativa dos indicadores de práticas alimentares do questionário utilizado na Pesquisa Nacional de Saúde do Escolar (PeNSE) entre adolescentes da cidade do Rio de Janeiro, Brasil. Foram estudados 174 alunos. Foram avaliados os indicadores: a ingestão regular (≥ 5 vezes/semana) dos alimentos marcadores de alimentação saudável, marcadores de alimentação não saudável e as rotinas alimentares: realizar refeição com responsável (REFEIÇÃO), realizar o desjejum (DESJEJUM) e comer enquanto estuda ou assiste à TV. Foram comparados os resultados do questionário e dos três recordatórios de 24 horas. Para todos os marcadores de alimentação saudável, não houve diferença na proporção de ingestão regular de acordo com os dois métodos. As frequências geradas pelo questionário foram superiores para os indicadores salgadinhos de pacote e biscoitos salgados e mais baixas para embutidos e REFEIÇÃO. Os indicadores de consumo regular de marcadores de alimentação saudável e aquele referente a DESJEJUM foram os que apresentaram maior acurácia. Os indicadores de práticas alimentares utilizados pela PeNSE apresentaram validade satisfatória.

Fluoride intake from food items in 2- to 6-year-old Brazilian children living in a non-fluoridated area using a semiquantitative food frequency questionnaire

BACKGROUND

Estimating fluoride intake (FI) using the 'duplicate plate' method is difficult and can raise ethical dilemmas.

AIM

To apply a semiquantitative food frequency questionnaire (FFQ) to 2- to 6-year-old Brazilian children in a non-fluoridated area (i) to estimate their FI and (ii) to provide additional validity to the questionnaire by comparing the results obtained with those found previously in a fluoridated municipality.

DESIGN

The FFQ was administered to parents of 398 children residing in a non-fluoridated community. Constituents of the diet were divided into solids, water and other beverages and their fluoride content was analysed with the electrode. Data were analysed using unpaired t-test.

RESULTS

The mean (±SD) FIs from solids, water and other beverages were 0.009 ± 0.004, 0.001 ± 0.001 and 0.007 ± 0.007 mg F/kg body weight/day, respectively, totalling 0.017 ± 0.009 mg F/kg body weight/day. Total FI from food/beverage items ingested in the non-fluoridated area was significantly lower than that observed in a study previously conducted in a fluoridated area (P < 0.0001).

CONCLUSIONS

This result reinforces the use of the FFQ as a promising alternative to duplicate diet in order to estimate FI in children in this age range, with potential application in broad epidemiological surveys.

Development of a quantitative food frequency questionnaire for Brazilian patients with type 2 diabetes

BACKGROUND

To investigate the association between dietary components and development of chronic diabetic complications, the dietary evaluation should include a long period, months or years. The present manuscript aims to develop a quantitative food frequency questionnaire (FFQ) and a portfolio with food photos to assess the usual intake pattern of Brazilian patients with type 2 diabetes to be used in future studies.

METHODS

Dietary data using 3-day weighed diet records (WDR) from 188 outpatients with type 2 diabetes were used to construct the list of usually consumed foods. Foods were initially clustered into eight groups: "cereals, tubers, roots, and derivatives"; "vegetables and legumes"; "fruits"; "beans"; "meat and eggs"; "milk and dairy products"; "oils and fats", and "sugars and sweets". The frequency of food intake and the relative contribution of each food item to the total energy and nutrient intakes were calculated. Portion sizes were determined according to the 25th, 50th, 75th, and 95th percentiles of intake for each food item.

RESULTS

A total of 62 food items were selected based on the 3-day WDR and another 27 foods or how they are prepared and nine beverages were included after the expert examination. Also, a portfolio with food photos of each included food item and portion sizes was made to assist the patients in identifying the consumed portion.

CONCLUSIONS

We developed a practical quantitative FFQ and portfolio with photos of 98 food items covering those most commonly consumed in the past 12 months, to assess the usual diet pattern of patients with type 2 diabetes in Southern Brazil.

Factors associated with the calibration of a food frequency questionnaire for the Bambuí Project, Brazil

BACKGROUND

The present study aimed to calibrate a food frequency questionnaire (FFQ) using one 24-h recall (R24) associated with foodstuff replicas.

METHODS

Calibration was performed by linear regression. Of a probability sample of 150 individuals (>18 years) of the town of Bambui, 98 completed the study.

RESULTS

The mean age of the participants was 43.8 years and 63.3% were women. The calibration of the FFQ included sex for the estimation of iron, protein and zinc; and an interaction between sex and R24 was significant for vitamin A and cholesterol models. Age contributed to the vitamin C, polyunsaturated fatty acids, proteins and zinc models, and an interaction between age and R24 was significant for protein and zinc.

CONCLUSIONS

Calibration coefficients and many interactions in linear regression models revealed important differences between dietary methods, indicating the complexity encountered when combining two methodologies for estimating food intake.

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

Esta revisão teve como objetivo analisar e discutir os procedimentos metodológicos empregados nos Questionários de Frequência Alimentar elaborados no Brasil. Foram consultadas as bases de dados PubMed, SciELO, Lilacs, IBECS, MedLine e Cochrane Library, e encontrados vinte e dois Questionários de Frequência Alimentar elaborados para populações brasileiras. Entre os Questionários de Frequência Alimentar encontrados 50% deles (n=11) foram elaborados a partir de recordatório de 24 horas, 27,27% (n=6) de Questionários de Frequência Alimentar pré-existentes, 13,63% (n=3) de registro alimentar e 9,09% (n=2) de outras fontes; 72,72% (n=16) apresentaram listas com 50 a 100 itens, número ideal. Quanto ao tipo, 45,45% (n=10) eram quantitativos, 45,45% (n=10) semiquantitativos e 9,09% (n=2) qualitativos. Apenas 27,27% (n=6) relataram teste em estudo-piloto e apenas 45,45% (n=10) referiram teste de validação ou validação e reprodutibilidade. Quanto à faixa etária, apenas 36,36% (n=8) dos Questionários de Frequência Alimentar apresentavam público-alvo específico: crianças, adolescentes ou adultos. O maior número de Questionários de Frequência Alimentar (54,54%; n=12) foi desenvolvido na região Sudeste, especialmente no estado de São Paulo. A revisão da literatura permitiu conhecer os Questionários de Frequência Alimentar elaborados para a população brasileira e suas respectivas metodologias, público-alvo, bem como sua distribuição em termos de região do País. Embora exista uma orientação em termos de proposta metodológica de elaboração aqui discutida, há algum distanciamento em relação ao recomendado que deve ser observado pelos pesquisadores da área, ainda que haja uma maioria de procedimentos adequados aos métodos pressupostos.

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INTRODUÇÃO: A despeito do aumento expressivo da população idosa nos últimos anos, são escassos os estudos brasileiros relacionados ao consumo alimentar desses indivíduos. OBJETIVOS: Propor uma lista de alimentos mais consumidos por idosos residentes na Zona Leste de São Paulo e analisar os alimentos que contribuem para o consumo de nutrientes relevantes ao estado nutricional e, consequentemente, à saúde dos idosos. MÉTODOS: Foram avaliados 100 indivíduos acima de 60 anos, frequentadores de um centro de referência. Para caracterização do estado nutricional foi calculado o Índice de Massa Corporal (IMC). Para elaboração das listas de alimentos foram aplicados dois recordatórios alimentares de 24 horas (RA24h) em duas estações diferentes do ano, que foram analisados quanto à frequência de consumo de cada alimento e quanto à contribuição percentual de energia, macronutrientes, fibras, cálcio e vitamina D. RESULTADOS: Com relação ao estado nutricional, 52% apresentaram o IMC < 28 kg/m²; 15% entre 28 e 30 kg/m²; 26% entre 30 e 35 kg/m² e 7% com IMC > 35 kg/m². O aspecto positivo da dieta foi a preservação de hábitos saudáveis como o consumo de arroz e feijão, e também de vegetais verde-escuros. Como aspecto negativo observou-se que a dieta dos idosos é monótona, pois poucos alimentos contribuem para o consumo de vários nutrientes. Além disso, houve um elevado consumo de carboidratos refinados em detrimento do consumo de alimentos integrais. CONCLUSÕES: As listas de alimentos obtidas, além de permitirem a reflexão sobre intervenções educativas, permitem o desenvolvimento subsequente de um Questionário de Frequência Alimentar específico para esse grupo.

Validação de indicadores do consumo de alimentos e bebidas obtidos por inquérito telefônico em Belém, Pará, Brasil

O objetivo deste trabalho foi avaliar a validade relativa dos indicadores de consumo de alimentos e bebidas obtidos pelo sistema de vigilância por entrevista telefônica (VIGITEL). Foi avaliada uma amostra aleatória (n = 100) da amostra total de aproximadamente dois mil adultos, estudada pelo sistema, em 2009, em Belém, Pará, Brasil. Os indicadores avaliados foram fatores de proteção (consumo adequado de frutas, legumes e verduras) e de risco (consumo de gordura saturada, refrigerante e bebidas alcoólicas) para doenças crônicas não transmissíveis. Compararam-se os resultados obtidos a partir de entrevista telefônica e de três recordatórios de 24 horas (padrão de referência). O padrão de referência evidenciou subestimação na frequência dos indicadores, à exceção de refrigerantes e bebidas alcoólicas. As médias das frequências do consumo foram, em geral, maiores no grupo exposto (entrevistados pelo VIGITEL). Não se pode concluir que o VIGITEL não seja um bom indicador de consumo, pois o padrão de referência também apresenta limitações, portanto o uso daquele como instrumento de monitoramento é justificável.

Desenvolvimento de Questionário de Frequência Alimentar para adultos em amostra de base populacional de Cuiabá, Região Centro-Oeste do Brasil

OBJETIVO: Descrever a construção de um Questionário de Frequência Alimentar (QFA) para utilização em estudos que visem à obtenção de dados sobre o consumo alimentar de adultos de Cuiabá, MT. MÉTODOS: Um inquérito recordatório de 24 horas (R24h) foi aplicado em uma subamostra de 104 indivíduos, de ambos os sexos, selecionados aleatoriamente a partir de uma amostra probabilística de estudo de base populacional. Considerando-se frequência de citação e contribuição para o consumo de energia e nutrientes dos alimentos citados nos R24h foram selecionados 81 itens alimentares e as respectivas porções de referência, que foram aquelas mais frequentemente relatadas nos R24h. A lista do QFA foi gerada com oito categorias de resposta para a frequência de consumo. RESULTADOS: Os itens alimentares citados por mais de 50% da amostra foram o açúcar, café, feijão, arroz, carne, pão e refrigerante, sendo que os quatro últimos também foram os que mais contribuíram para o consumo energético. Não se observaram diferenças entre homens e mulheres nos alimentos que mais contribuíram para a ingestão de macro e micronutrientes. CONCLUSÃO: O QFA foi desenvolvido com a inclusão dos itens alimentares de maior relevância para a dieta da população adulta de Cuiabá, Mato Grosso. Comprovadas sua validade e reprodutibilidade, este instrumento será útil em investigações epidemiológicas e clínicas sobre o possível papel da dieta no desenvolvimento de enfermidades nessa população.

Associação entre prática de atividade física, escolaridade e perfil alimentar de motoristas de caminhão

A demanda da sociedade moderna intensificou o trabalho ininterrupto em diversas profissões. Além disso, o modo de organização da sociedade, com atividades predominantemente mecanizadas, tem contribuído para a prevalência de hábitos de vida não saudáveis, como a inatividade física. Este estudo objetiva verificar se fatores ocupacionais, sociodemográficos, antropométricos e alimentares estão associados à prática de atividade física insuficiente e se há diferenças nessa associação entre motoristas de caminhão que trabalham de dia ou à noite. Participaram da pesquisa 470 motoristas de caminhão, que responderam a questionários de dados sociodemográficos, atividade física e frequência alimentar. Foi realizada uma regressão logística univariada para verificar a associação entre atividade física insuficiente e as demais variáveis. Além disso, a regressão logística múltipla foi testada para obter modelos que mostrem a associação de conjuntos de variáveis relacionados à atividade física insuficiente. Os resultados indicaram que a prática de atividade física está associada ao maior nível de escolaridade (OR = 1,84; IC = 1,22-2,76) e menor consumo de bebidas alcoólicas (OR = 1,59; IC = 1,04-2,45). Maior ingestão de cereais integrais (OR = 1,63; IC = 1,08-2,46) foi associada à prática regular de atividade física. Entre os trabalhadores noturnos, foi encontrada associação entre a prática regular de atividade física, maior consumo de cereais integrais (OR = 2,02; IC =1,13-3,60) e menor consumo de carboidratos simples (OR = 1,91; IC = 1,08-3,37).

Fluoride ingestion from food items and dentifrice in 2-6-year-old Brazilian children living in a fluoridated area using a semiquantitative food frequency questionnaire

OBJECTIVES

The aim of this study was to evaluate the fluoride intake of 2-6-year-old Brazilian children using a semiquantitative food frequency questionnaire (FFQ) which also estimated fluoride intake from dentifrice.

METHODS

The FFQ was previously validated through application to 78 2-6-year-old Brazilian children and then administered to 379 children residing in an optimally fluoridated community in Brazil (Bauru, State of São Paulo). The FFQ was applied to the parents and used to estimate the food intake of the children. The constituents of the diet were divided into solids, water and other beverages. The fluoride content of the diet items was analyzed with the fluoride electrode. The questionnaire also estimated fluoride intake from dentifrice.

RESULTS

The average (+/-SD) fluoride intake from solids, water, other beverages and dentifrice was 0.008 +/- 0.005; 0.011 +/- 0.004; 0.009 +/- 0.014 and 0.036 +/- 0.028 mg F/kg body weight/day, respectively, totalizing 0.064 +/- 0.035 mg F/kg body weight/day. The dentifrice and the diet contributed with 56.3% and 43.7% of the daily fluoride intake, respectively. Among the children evaluated, 31.2% are estimated to have risk to develop dental fluorosis (intake>0.07 mg F/kg body weight/day).

CONCLUSIONS

The dentifrice was the main source of fluoride intake by the children evaluated. However, the fluoride concentration in food items also significantly contributed to the daily ingestion by 2-6-year-old children. The questionnaire used seems to be a promising alternative to duplicate diet to estimate the fluoride intake at this age range and may have potential to be used in broad epidemiological surveys.

Validation of a food frequency questionnaire for women with osteoporosis

The importance of nutrient intakes in osteoporosis prevention in treatment is widely recognized. The objective of the present study was to develop and validate a FFQ for women with osteoporosis. The questionnaire was composed of 60 items, separated into 10 groups. The relative validation was accomplished through comparison of the 3-Day Food Record (3DR) with the FFQ. The 3DR was applied to 30 elderly women with confirmed osteoporosis, and after 45 days the FFQ was administrated. Statistical analysis comprised the Kolmogorov-Smirnov, Student T test and Pearson correlation coefficient. The agreement between two methods was evaluated by the frequency of similar classification into quartiles, and by the Bland-Altman method. No significant differences between methods were observed for the mean evaluated nutrients, except for carbohydrate and magnesium. Pearson correlation coefficients were positive and statistically significant for all nutrients. The overall proportion of subjects classified in the same quartile by the two methods was on average 50.01% and in the opposite quartile 0.47%. For calcium intake, only 3% of subjects were classified in opposite extreme quartiles by the two methods. The Bland-Altman analysis demonstrated that the differences obtained by the two methods in each subject were well distributed around the mean of the difference, and the disagreement increases as the mean intake increases. These results indicates that the FFQ for elderly women with osteoporosis presented here is highly acceptable and is an accurate method that can be used in large-scale or clinical studies for evaluation of nutrient intakes in a similar population.

Avaliação de reprodutibilidade e validade de um questionário de freqüência alimentar em adultos residentes em Porto Alegre, Rio Grande do Sul, Brasil

O estudo avaliou a reprodutibilidade e a validade relativa de um questionário de freqüência alimentar (QFA) em 83 indivíduos adultos, do Sul do Brasil. Utilizou-se o coeficiente de correlação Intraclasse (ICC), classificação em quartos de ingestão pelo QFA e IR24h e índice Kappa ponderado. Os nutrientes foram log transformados e corrigidos para calorias. A atenuação nas correlações foi corrigida pela variabilidade intrapessoal. Para a reprodutibilidade, os valores das correlações variaram de 0,44 (IC95%: -0,19-0,76) a 0,83 (IC95%: 0,72-0,90) para carboidrato e vitamina C, respectivamente. No estudo de validade, os coeficientes deatenuados variaram de 0,23 (IC95%: -0,22-0,61) a 0,86 (IC95%: 0,21-1,16) para a vitamina A e lipídeos, no QFA1, e de 0,50 (IC95%: -016-0,91) a 0,95 (IC95%: 0,79-1,05) para vitamina A e energia, no QFA2. O índice Kappa ponderado apresentou valor mais baixo para o cálcio (0,10; IC95%: 0,00-0,26) e valores mais altos para vitamina C no QFA1 (0,38; IC95%: 0,23-0,53) e energia no QFA2 (0,38; IC95%: 0,24-0,52). Os resultados indicam reprodutibilidade satisfatória para todos os nutrientes, com exceção do carboidrato, e validade relativa razoável, especialmente para os macronutrientes e vitamina C.

Validação relativa de Questionário de Freqüência Alimentar em gestantes usuárias de serviços do Sistema Único de Saúde em dois municípios no Rio Grande do Sul, Brasil

OBJETIVOS: avaliar o desempenho do Questionário de Frequência Alimentar (QFA), desenvolvido por Sichieri e Everhart, em medir o consumo alimentar de gestantes atendidas pelo Sistema Único de Saúde (SUS), comparando as estimativas de consumo de energia e nutrientes com as obtidas por recordatórios alimentares. MÉTODOS: foram realizadas duas entrevistas com gestantes em atendimento pré-natal em Bento Gonçalves e Porto Alegre, no Rio Grande do Sul, Brasil. Na primeira, foi aplicado o QFA e, depois, os recordatórios alimentares relativos aos dois dias prévios. Na segunda, foram obtidos novos recordatórios. Médias e limites de concordância para as diferenças entre as duas avaliações de ingestão alimentar foram calculadas conforme Bland-Altman. RESULTADOS: a diferença entre os métodos mostrou que o QFA superestimou o consumo de energia e nutrientes. O coeficiente de correlação ajustado para energia variou de 0,01 (gordura insaturada) a 0,47 (cálcio). Correlações maiores foram observadas para fibras, vitamina C, ácido fólico, cálcio e potássio. Em média, 30% das gestantes foram classificadas no mesmo quartil de consumo. CONCLUSÕES: o QFA pode ser uma ferramenta útil para avaliar consumo de gestantes em estudos epidemiológicos, contanto que sejam realizados esforços para melhorar seu desempenho. É necessário avaliar a influência de características sócio-demográficas e estado de saúde na validade do método.

Validação do Questionário de Freqüência Alimentar para Adolescentes (QFAA) por grupos de alimentos em uma população de escolares

OBJETIVO: Verificar a validade do Questionário de Freqüência Alimentar para Adolescentes para avaliar o consumo de grupos de alimentos entre escolares de Piracicaba, São Paulo. MÉTODOS: Participaram do estudo 94 adolescentes, com idade entre 11 e 15 anos, matriculados em uma escola da rede pública. O consumo alimentar foi avaliado pelo Questionário de Freqüência Alimentar para Adolescentes (QFAA) e a média de dois Recordatórios de 24 horas (R24h) foi utilizada como método de referência. Os itens alimentares foram classificados em 18 grupos. Foram realizadas análises descritivas, teste t-Student pareado e de Wilcoxon, coeficientes de correlação de Pearson e de Spearman. Foram também utilizadas análise de quartis e estatística Kappa ponderado. Os coeficientes de correlação foram corrigidos pela variância intrapessoal dos R24h, estimada a partir de ANOVA com um fator de classificação. RESULTADOS: Não foram verificadas diferenças significativas entre os instrumentos para o arroz, massas, carnes, refrigerantes e sucos artificiais. Os coeficientes de correlação corrigidos pela variabilidade intrapessoal variaram de -0,26 a 0,78. A concordância de classificação dos indivíduos no mesmo quartil de consumo para ambos os métodos variou de 22% (massas) a 50% (feijão). Para quartis opostos, os grupos que tiveram mais de 10% dos indivíduos classificados incorretamente foram massas (19%), carnes (13%) e gorduras (11%). Os valores de Kappa ponderado variaram de - 0,15 (massas) a 0,56 (feijão). O QFAA superestimou o consumo de quase a totalidade dos grupos alimentares e subestimou os grupos dos óleos, feijão, carnes e refrigerantes. CONCLUSÃO: O instrumento apresentou boa validade para feijão, verduras e legumes, leite e derivados, biscoitos recheados e para o arroz.

[Historical tendencies of diet studies in Brazil]

The objective of this work was to conduct a historical analysis of diet studies in Brazil, from mid-XIX century to early XXI century. The method involved a bibliographical review to identify and analyze the different kinds and main results of surveys on food consumption in the country, by means of six intentionally established transversal cuts (1837-1899; 1900-1929; 1930-1939; 1940-1969; 1970-1989 e 1990-2005). Several methodological procedures to evaluate individual and population diets were found: food history; 24-hour dietary recall; food intake diary or register; food weight and measures; food intake frequency questionnaire, and research on food budget. We conclude that food consumption evaluation methods and tools have improved simultaneously to deep and substantial changes in consumption patterns and food habits among the Brazilian population.

Validação de um questionário de freqüência de consumo alimentar para população adulta

OBJETIVO: Investigar a validade e a reprodutibilidade de um questionário de freqüência de consumo alimentar desenvolvido para a população adulta. MÉTODOS: Foram entrevistados, em três momentos, 69 indivíduos, de ambos os sexos, freqüentadores de restaurantes industriais em dois órgãos públicos de Brasília, Distrito Federal. Na primeira e terceira entrevistas foram aplicados um recordatório 24 horas e um questionário de freqüência de consumo alimentar, e na segunda entrevista, um recordatório 24 horas. A duração média do estudo foi de 181 dias. Macronutrientes, vitaminas A e C, cálcio, ferro, zinco, colesterol, fibras e energia total foram analisados utilizando-se os coeficientes de correlação intraclasse e de Pearson, este último na forma bruta e deatenuada. RESULTADOS: Quanto à reprodutibilidade, o questionário de freqüência de consumo alimentar obteve desempenho adequado, apresentando resultados acima de 0,7 para lipídeo, colesterol, energia e proteína. Para a validade, os melhores coeficientes deatenuados foram observados para vitamina C (r=0,66), ferro (r=0,58), proteína (r=0,55) e carboidrato (r=0,55) e os piores, para colesterol (r=0,32) e vitamina A (r=0,37). CONCLUSÃO: A obtenção de coeficientes de correlação expressivos para alguns nutrientes indica que este questionário de freqüência de consumo alimentar constitui-se em um bom instrumento de pesquisa para estudos epidemiológicos em população adulta, podendo fornecer informações importantes para a implementação de ações na área de saúde e nutrição.