[Assessment of food consumption and nutrient intake in clinical practice]

The assessment of food consumption in clinical practice is often carried out to develop and implement nutritional advice. Factors as the patient health conditions, the evolution of his/her clinical condition as well as the reasons that motivated the search for advice will guide the selection of the best method of assessment of food consumption or nutrient intake to employ. The chosen method might drive the professional to offer a food plan that aims to promote health, to prevent illness, and to alter the nutritional state of the patient. Despite the easily available national literature on methods and techniques to estimate food consumption, it is not uncommon that professionals still have doubts about what methods are the most appropriated in daily practice. This study aimed to present a critical analysis, taking into account the clinical applicability, of the food assessment methods and its characteristics.

Identification of dietary patterns using factor analysis in an epidemiological study in São Paulo

CONTEXT AND OBJECTIVE

Diet and nutrition are environmental factors in health/disease relationships. From the epidemiological viewpoint, diet represents a complex set of highly correlated exposures. Our objective was to identify patterns of food intake in a group of individuals living in São Paulo, and to develop objective dietary measurements for epidemiological purposes. DESIGN AND LOCAL: Exploratory factor analysis of data in a case-control study in seven teaching hospitals in São Paulo.

METHODS

The participants were 517 patients (260 oral cancer cases and 257 controls) admitted to the study hospitals between November 1998 and March 2001. The weekly intake frequencies for dairy products, cereals, meat, processed meat, vegetables, pulses, fruits and sweets were assessed by means of a semi-quantitative food frequency questionnaire. Dietary patterns were identified by factor analysis, based on the intake of the eight food groups, using principal component analysis as an extraction method followed by varimax rotation.

RESULTS

Factor analysis identified three patterns that accounted for 55% of the total variability within the sample. The first pattern ("prudent") was characterized by vegetable, fruit and meat intake; the second ("traditional") by cereals (mainly rice) and pulses (mainly beans); and the third ("snacks") by dairy products and processed meat.

CONCLUSION

This study identified food intake patterns through an a posteriori approach. Such analysis may be useful for nutritional intervention programs and, after computing scores for each individual according to the patterns identified, for establishing a relationship between diet and other epidemiological measurements of interest.

[Food frequency questionnaire for adults from a population-based study]

The objective of the study was to develop a food frequency questionnaire for each of the following groups: female adults, male adults and male and female adults, based on dietary data obtained in a population-based study comprising individuals from different income levels. Dietary data was obtained from a 24-hour Dietary Recall applied to a probabilistic sample of 1,477 subjects in the city of São Paulo (Southeastern Brazil) in 2003. Food items accounting for at least 90% of total daily calorie intake and nutrients were selected. The reference time frame was the year preceding the interview and subjects had the choice of four serving sizes.

Ingestão inadequada de nutrientes na população de idosos do Brasil: Inquérito Nacional de Alimentação 2008-2009

OBJETIVO: Estimar a prevalência de ingestão inadequada de nutrientes na população idosa brasileira. MÉTODOS: Foram analisados dados do Inquérito Nacional de Alimentação como parte da Pesquisa de Orçamentos Familiares, em 2008-2009. Dados de consumo alimentar individual de 4.322 indivíduos com 60 anos ou mais foram obtidos por meio do registro alimentar de dois dias não consecutivos. A ingestão habitual para cada nutriente foi estimada pelo método do National Cancer Institute, cujos modelos tiveram como covariáveis sexo e região. As prevalências de inadequação de ingestão de micronutrientes foram estimadas segundo sexo e região utilizando o método da EAR como ponte de corte. RESULTADOS: Elevadas prevalências de inadequação (> 50%) foram observadas para as vitaminas E, D, A, cálcio, magnésio e piridoxina em ambos os sexos. Em todas as regiões, observou-se 100% de inadequação de vitamina E. Vitamina D obteve percentuais de inadequação próximos de 100% em todas as regiões, exceto para a região Norte. As prevalências de inadequação de vitamina A foram superiores a 70% nas regiões Norte, Nordeste e Centro-Oeste. Cálcio e magnésio foram os minerais com maior prevalência de ingestão inadequada (> 80%) em todas as regiões. CONCLUSÕES: Idosos brasileiros apresentam elevada inadequação da ingestão de nutrientes, reconhecidos como protetores contra doenças crônicas.

Evaluation of the reliability and validity of the Brazilian Healthy Eating Index Revised

OBJECTIVE

Evaluate validity and reliability of the Brazilian Healthy Eating Index Revised according to the psychometric properties.

METHODS

Cross-sectional study of a random sample of 2,375 individuals of both sexes, aged 12 or older from the city of São Paulo, Southeastern Brazil, drawn from the Health Survey carried out in 2003. Information on the population characteristics was acquired using a questionnaire. Food intake was obtained using 24h Recall, used to calculate the Brazilian Healthy Eating Index Revised (BHEI-R). The following aspects were evaluated: (1) content validity, by comparing the components with the Dietary Guidelines for the Brazilian Population; (2) construct validity, factor analysis using principal components method and verifying whether the index can measure diet quality regardless of energy intake; (3) discriminating validity; and (4) the reliability of the BHEI-R by analyzing the internal consistency of the items using Cronbach's alpha coefficient.

RESULTS

The correlations between the component scores and energy intake were weak (r < 0.30). Principal component analysis indicated the presence of four factors with eigenvalues > 1 that represented 67% of the index variance. The discriminating validity of the BHEI-R was observed by comparing the individuals by sex and smoking habit, and identifying statistically significant differences between the means of the components of the BHEI-R and the final score. The Cronbach's alpha value (α = 0.7) indicated the presence of internal consistency between the components of the BHEI-R. The SoFAAS component followed by the total fruit component and whole fruit component presented greater correlation with the final index scores.

CONCLUSIONS

The Brazilian Healthy Eating Index Revised showed itself to be reliable and structurally valid when used to evaluate and monitor the diet quality of Brazilians.

Trends in diet quality among adolescents, adults and older adults: A population-based study

This study aimed to monitor diet quality and associated factors in adolescents, adults and older adults from the city of São Paulo, Brazil. We conducted a cross-sectional population-based study involving 2376 individuals surveyed in 2003, and 1662 individuals in 2008 (Health Survey of São Paulo, ISA-Capital). Participants were of both sexes and aged 12 to 19 years old (adolescents), 20 to 59 years old (adults) and 60 years old or over (older adults). Food intake was assessed using the 24-h dietary recall method while diet quality was determined by the Brazilian Healthy Eating Index (BHEI-R). The prevalence of descriptive variables for 2003 and 2008 was compared adopting a confidence interval of 95%. The means of total BHEI-R score and its components for 2003 and 2008 were compared for each age group. Associations between the BHEI-R and independent variables were evaluated for each survey year using multiple linear regression analysis. Results showed that the mean BHEI-R increased (54.9 vs. 56.4 points) over the five-year period. However, the age group evaluation showed a deterioration in diet quality of adolescents, influenced by a decrease in scores for dark-green and orange vegetables and legumes, total grains, oils and SoFAAS (solid fat, alcohol and added sugar) components. In the 2008 survey, adults had a higher BHEI-R score, by 6.1 points on average, compared to adolescents. Compared to older adults, this difference was 10.7 points. The diet quality remains a concern, especially among adolescents, that had the worst results compared to the other age groups.

Excessive meat consumption in Brazil: diet quality and environmental impacts

OBJECTIVE

To evaluate red and processed meat intake, and the impact meat consumption has on diet quality and the environment.

DESIGN

A large cross-sectional health survey performed in São Paulo, Brazil.

SETTING

Diet was assessed by two 24 h dietary recalls. Usual intakes were calculated using the Multiple Source Method. The World Cancer Research Fund recommendation of an average of 71.4 g/d was used as the cut-off point to estimate excessive red and processed meat consumption. To investigate the relationship between meat consumption and diet quality we used the Brazilian Healthy Eating Index Revised. The environmental impact was analysed according to estimates of CO2 equivalent emissions from meat consumption.

SUBJECTS

Brazilians (n 1677) aged 19 years and older were studied.

RESULTS

The mean red and processed meat intake was 138 g/d for men and 81 g/d for women. About 81% of men and 58% of women consumed more meat than recommended. Diet quality was inversely associated with excessive meat intake in men. In Brazil alone, greenhouse gas emissions from meat consumption, in 2003, were estimated at approximately 18,071,988 tonnes of CO2 equivalents, representing about 4% of the total CO2 emitted by agriculture.

CONCLUSIONS

The excessive meat intake, associated with poorer diet quality observed, support initiatives and policies advising to reduce red and processed meat intake to within the recommended amounts, as part of a healthy and environmentally sustainable diet.

Validation and calibration of self-reported weight and height from individuals in the city of São Paulo

OBJECTIVE

To evaluate the validity of self-reported weight and height measurements among residents of São Paulo, as well as the accuracy of these measurements for determining nutritional status, and to present calibration coefficients.

METHODS

A cross-sectional, population-based study was performed with a sample of 299 adolescents, adults and elderly of both genders, in São Paulo in 2008. Bland-Altman difference plot and intraclass correlation were used to determine agreement between measured and self-reported parameters. Sensitivity and specificity were assessed for overweight, and calibration coefficients were estimated for correction of weight, height and body mass index data.

RESULTS

The intraclass correlation was high between self-reported and measured parameters for weight (r > 0,94) and body mass index (BMI) (r > 0,85). The agreement between measured and self-reported weight, height and BMI was good. Sensibility was > 91% and specificity was > 83%.

CONCLUSION

Self-reported weight measurements can substitute measured parameters in this population, in both genders and in the age groups studied. Self-reported height measurements should be used with caution. Calibration coefficients can be used to adjust self-reported measurements.

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 of a food frequency questionnaire for adolescents

To assess the reproducibility of a validated 76-item food frequency questionnaire designed to estimate diet in adolescents (Adolescent Food Frequency Questionnaire--AFFQ) in the city of Sao Paulo, Brazil, a test-retest study was conducted (n = 49). Intraclass correlation coefficient (ICC), weighted kappa, and percentage of agreement were used in both crude and energy-adjusted nutrient intakes. Bland Altman plots were used to examine the limits of agreement for energy and macronutrients. The ICC ranged from 0.48 (carbohydrates) to 0.65 (vitamin C) in crude values and from 0.25 (total fat) to 0.58 (vitamin C) in adjusted values. Kappa values ranged from 0.28 (protein and fiber) to 0.56 (unsaturated fat). Bland Altman showed a trend towards larger difference in energy according to increased intake values and a bias towards extreme values for fat intake. The percent of individuals classified in the same category on the two occasions was on average 54.2%. By conclusion, the Adolescent Food Frequency Questionnaire showed reasonable reproducibility and can be used in studies that aim to classify groups into intake categories.

Associations between dietary patterns and self-reported hypertension among Brazilian adults: a cross-sectional population-based study

Hypertension is a prevalent cardiovascular disease, the important modifiable risk factor of which is diet. The aim of this study was to derive dietary patterns and to test associations with self-reported hypertension and other characteristics, namely demographic, socioeconomic, and lifestyle factors. Data were obtained from the population-based cross-sectional study titled Health Survey of the City of São Paulo, with a random sample of residents of the city of São Paulo, Brazil, aged older than 20 years of both sexes (n=1,102). In 2008, a structured questionnaire with information about socioeconomic, anthropometric, lifestyle, and dietary factors was applied. Dietary intake was estimated by two 24-hour dietary recalls, adjusted by Multiple Source Method. Dietary patterns were obtained through exploratory principal component factor analysis. Poisson regression was used to assess relationships. Three dietary patterns were identified: prudent (fruits, vegetables, whole-grain bread, white cheeses, juices, reduced-fat milk/nonfat milk), traditional (rice, beans, bread/toast/crackers, butter/margarine, whole milk, coffee/teas, sugar), and modern (sodas, pastries/sandwiches/pizzas, yellow cheeses, pastas, sauces, alcoholic beverages, sweets, processed meats). Hypertension and demographic, socioeconomic, and lifestyle factors, as well as the presence of health insurance, were associated with adherence to one or more identified dietary patterns. These results suggest the existence of a target audience for planning and executing public policies of food and nutrition to prevent and control hypertension.

Dietary patterns and risk of oral cancer: a case-control study in São Paulo, Brazil

OBJECTIVE: To analyze the association between dietary patterns and oral cancer. METHODS: The study, part of a Latin American multicenter hospital-based case-control study, was conducted in São Paulo, Southeastern Brazil, between November 1998 and March 2002 and included 366 incident cases of oral cancer and 469 controls, frequency-matched with cases by sex and age. Dietary data were collected using a food frequency questionnaire. The risk associated with the intake of food groups defined a posteriori, through factor analysis (called factors), was assessed. The first factor, labeled "prudent," was characterized by the intake of vegetables, fruit, cheese, and poultry. The second factor, "traditional," consisted of the intake of rice, pasta, pulses, and meat. The third factor, "snacks," was characterized as the intake of bread, butter, salami, cheese, cakes, and desserts. The fourth, "monotonous," was inversely associated with the intake of fruit, vegetables and most other food items. Factor scores for each component retained were calculated for cases and controls. After categorization of factor scores into tertiles according to the distribution of controls, odds ratios and 95% confidence intervals were calculated using unconditional multiple logistic regression. RESULTS: "Traditional" factor showed an inverse association with cancer (OR=0.51; 95% CI: 0.32; 0.81, p-value for trend 0.14), whereas "monotonous" was positively associated with the outcome (OR=1.78; 95% CI: 1.78; 2.85, p-value for trend <0.001). CONCLUSIONS: The study data suggest that the traditional Brazilian diet, consisting of rice and beans plus moderate amounts of meat, may confer protection against oral cancer, independently of any other risk factors such as alcohol intake and smoking.

Nutritional quality of major meals consumed away from home in Brazil and its association with the overall diet quality

OBJECTIVE

The objective of the study is to evaluate the nutritional quality of meals consumed away from home and its association with overall diet quality.

METHOD

Data was obtained from 834 participants of a Health Survey in São Paulo, Brazil. Food intake was measured by a 24-hour dietary recall applied telephonically using the Automated Multiple-Pass Method. Overall dietary quality was assessed by the Brazilian Healthy Eating Index Revised (B-HEIR) and the Meal Quality Index (MQI) was used to evaluate dietary quality of the main meals. The association between the B-HEIR and the MQI was assessed by linear regression analysis.

RESULTS

The consumption of at least one of the three main meals away from home was reported for 32% of respondents (70 adolescents, 156 adults and 40 elderly). The average MQI score of lunch consumed away from home was lower than lunch consumed at home, with higher amounts of total and saturated fats. The average score of B-HEIR was 58 points and was associated with the MQI score, energy, meal consumption location and gender.

CONCLUSION

Lunch consumed away from home presented the worst quality, being higher in total and saturated fat. However, the meals consumed at home also need improvement.

Empirically derived dietary patterns: interpretability and construct validity according to different factor rotation methods

This study aimed to investigate the effects of factor rotation methods on interpretability and construct validity of dietary patterns derived in a representative sample of 1,102 Brazilian adults. Dietary patterns were derived from exploratory factor analysis. Orthogonal (varimax) and oblique rotations (promax, direct oblimin) were applied. Confirmatory factor analysis assessed construct validity of the dietary patterns derived according to two factor loading cut-offs (≥ |0.20| and ≥ |0.25|). Goodness-of-fit indexes assessed the model fit. Differences in composition and in interpretability of the first pattern were observed between varimax and promax/oblimin at cut-off ≥ |0.20|. At cut-off ≥ |0.25|, these differences were no longer observed. None of the patterns derived at cut-off ≥ |0.20| showed acceptable model fit. At cut-off ≥ |0.25|, the promax rotation produced the best model fit. The effects of factor rotation on dietary patterns differed according to the factor loading cut-off used in exploratory factor analysis.

[Underreporting of energy intake and associated factors in a population-based study]

This study aimed to identify the prevalence of underreporting of energy intake and associated factors in a sample of 331 individuals from the population-based Health Survey in the City of São Paulo, Brazil. Energy intake was assessed by averaging two 24-hour recalls collected on nonconsecutive days. Total energy expenditure was calculated by the predictive equation, and under-reporters were defined as individuals with energy intake less than 2 standard deviations from the energy intake/predicted total energy expenditure ratio. Poisson regression was used to identify factors associated with underreporting. Prevalence of underreporting of energy intake was 15.1%, whereas individuals with overweight and dissatisfied with body weight were more likely to underreport when compared to individuals without excess weight and who were satisfied with body weight, respectively. We conclude that these factors should be considered when developing techniques to improve the accuracy of dietary assessment.

Estado nutricional e fatores associados ao déficit de crescimento de crianças freqüentadoras de creches públicas do Município de São Paulo, Brasil

O presente estudo relata o estado nutricional de crianças freqüentadoras de creches da rede municipal de São Paulo, Brasil. Foi avaliada uma amostra representativa das crianças atendidas, totalizando 827 crianças menores de 84 meses. Características sócio-econômicas, dados de morbidade e o estado nutricional (altura/idade e/ou peso/altura) foram obtidos. Verificou-se que 7,0% (IC95%: 3,60-10,40) das crianças apresentavam déficit de altura. Na análise univariada, os fatores que se associaram ao déficit nutricional foram: idade da criança (< 24 meses), RC = 2,10 (IC95%: 1,11-3,98); relato de diarréia no mês anterior, RC = 2,84 (IC95%: 1,42-5,66); escolaridade do responsável até três anos de estudo, RC = 3,87 (IC95%: 1,10-13,68); número de moradores no domicílio (sete ou mais), RC = 3,02 (IC95%: 1,46-6,22); número de irmãos (dois ou mais), RC = 4,81 (IC95%: 1,72-13,44). Na análise multivariada, a ocorrência de diarréia no mês anterior e número de irmãos mantiveram-se associados ao retardo de crescimento (RC = 2,54; IC95%: 1,20-5,38 e RC = 7,40; IC95%: 2,20-24,93, respectivamente).

Dietary patterns and risk of oral and pharyngeal cancer: a case-control study in Rio de Janeiro, Brazil

The study investigated the association between dietary patterns and oral cancer as part of a Latin American multicenter hospital-based case-control study, and included 210 incident cases of oral cancer and 251 controls. Dietary data were collected using a Food Frequency Questionnaire (FFQ). Factor analysis was used to define dietary patterns, which were categorized into terciles. Odds ratios (OR) with 95% confidence intervals (95%CI) were calculated using unconditional multiple logistic regression. The patterns "prudent", characterized mainly by vegetables and fruits, and "traditional", by rice, and pulses showed an inverse association with oral cancer for the higher tercile, respectively, OR = 0.44; 95%CI: 0.25-0.75, p value for trend (p tend) = 0.03; OR = 0.53; 95%CI: 0.30-0.93, p tend = 0.06. The "snacks pattern" was not associated with oral cancer. Besides the protective effect of a diet rich in vegetables and fruit, our data suggest that the traditional Brazilian diet, consisting mostly of rice and beans, may improve protection against oral cancer.

A quantile regression approach can reveal the effect of fruit and vegetable consumption on plasma homocysteine levels

INTRODUCTION

A reduction in homocysteine concentration due to the use of supplemental folic acid is well recognized, although evidence of the same effect for natural folate sources, such as fruits and vegetables (FV), is lacking. The traditional statistical analysis approaches do not provide further information. As an alternative, quantile regression allows for the exploration of the effects of covariates through percentiles of the conditional distribution of the dependent variable.

OBJECTIVE

To investigate how the associations of FV intake with plasma total homocysteine (tHcy) differ through percentiles in the distribution using quantile regression.

MATERIALS AND METHODS

A cross-sectional population-based survey was conducted among 499 residents of Sao Paulo City, Brazil. The participants provided food intake and fasting blood samples. Fruit and vegetable intake was predicted by adjusting for day-to-day variation using a proper measurement error model. We performed a quantile regression to verify the association between tHcy and the predicted FV intake. The predicted values of tHcy for each percentile model were calculated considering an increase of 200 g in the FV intake for each percentile.

RESULTS

The results showed that tHcy was inversely associated with FV intake when assessed by linear regression whereas, the association was different when using quantile regression. The relationship with FV consumption was inverse and significant for almost all percentiles of tHcy. The coefficients increased as the percentile of tHcy increased. A simulated increase of 200 g in the FV intake could decrease the tHcy levels in the overall percentiles, but the higher percentiles of tHcy benefited more.

CONCLUSIONS

This study confirms that the effect of FV intake on lowering the tHcy levels is dependent on the level of tHcy using an innovative statistical approach. From a public health point of view, encouraging people to increase FV intake would benefit people with high levels of tHcy.

Aplicação das Dietary Reference Intakes na avaliação da ingestão de nutrientes para indivíduos

A avaliação do estado nutricional é uma das práticas clínicas fundamentais para tomar-se a decisão quanto ao diagnóstico nutricional de um indivíduo e à conduta dietética a ser-lhe prescrita. A adequação da ingestão de nutrientes é um dos componentes da avaliação nutricional e é feita a partir de valores de referência que se constituem em estimativas das necessidades fisiológicas desses nutrientes e metas de ingestão dos mesmos. Colocam-se hoje à disposição dos profissionais um novo conjunto de valores de referência que constituem um avanço importante no modo de interpretar a adequação dietética: as Dietary Reference Intakes. Este artigo aborda os métodos propostos para avaliação da adequação da ingestão de nutriente às necessidades do indivíduo, utilizando os novos valores de referências.

Reprodutibilidade e validade do questionário de freqüência de consumo alimentar utilizado em estudo caso-controle de câncer oral

O objetivo deste trabalho foi verificar a reprodutibilidade e validade do questionário de freqüência de consumo alimentar utilizado no Estudo Latino-Americano sobre Câncer Oral e de Laringe. Uma amostra de 35 indivíduos, considerados controle no Estudo Latino-Americano, foi entrevistada por telefone. Foi reaplicado o questionário de freqüência idêntico ao do Estudo Latino-Americano e aplicado um recordatório de 24 horas. A reprodutibilidade foi avaliada pela comparação do consumo alimentar obtido nos dois questionários de freqüência, e a validade pela comparação do consumo obtido no recordatório de 24 horas e no segundo questionário de freqüência. Na comparação entre os questionários foi utilizado o teste de Wilcoxon para medir as diferenças no consumo, o coeficiente de Spearman para avaliar as correlações, a correlação intraclasse para estimar a variação intrapessoal, e o teste Kappa para avaliar a concordância no consumo. Na análise da reprodutibilidade ocorreram diferenças estatisticamente significantes para o consumo de massas e leguminosas. Na análise da validade ocorreram diferenças estatisticamente significantes para manteiga, tubérculos, frango, hortaliças, leguminosas e frutas, sendo que, em geral, o questionário de freqüência superestimou o consumo destes grupos de alimentos. A concordância de classificação por tercis variou de 40% a 80% entre os dois questionários de freqüência, e de 31% a 74% entre o recordatório e o segundo questionário de freqüência. Os resultados indicam que o questionário de freqüência utilizado no Estudo Latino-Americano tem boa reprodutibilidade e razoável validade para estimar o consumo de alimentos.