Repositório RCAAP

The aim of this study was to describe oral health follow-up studies nested in a birth cohort. A population-based birth cohort was launched in 1993 in Pelotas, Rio Grande do Sul State, Brazil. Two oral health follow-up studies were conducted at six (n = 359) and 12 (n = 339) years of age. A high response rate was observed at 12 years of age; 94.4% of the children examined at six years of age were restudied in 2005. The mean DMF-T index at age 12 was 1.2 (SD = 1.6) for the entire sample, ranging from 0.6 (SD = 1.1) for children that were caries-free at age six, 1.3 (SD = 1.5) for those with 1-3 carious teeth at six years, and 1.8 (SD = 1.8) for those with 4-19 carious teeth at six years (p < 0.01). The number of individuals with severe malocclusions at 12 years was proportional to the number of malocclusions at six years. Oral health problems in early adolescence were more prevalent in individuals with dental problems at six years of age.

Folate deficiency has been associated with anemia and other adverse outcomes in pregnancy such as neural tube defects. The current recommendations for prevention of such outcomes are difficult to achieve through diet only, and folic acid supplementation and food fortification are feasible public health strategies. However, it is necessary to determine the usual diet and supplement use among women of reproductive age, including an accurate assessment of other dietary micronutrients. In addition to the beneficial effects observed in randomized clinical trials, health risks to the population have also been widely evaluated and discussed in the scientific community: for a minority to benefit from fortification programs, many are exposed to high folic acid intake levels.

The triads method is applied in validation studies of dietary intake to evaluate the correlation between three measurements (food frequency questionnaire, reference method and biomarker) and the true intake using validity coefficients (Á). The main advantage of this technique is the inclusion of the biomarker, which presents independent errors compared with those of the traditional methods. The method assumes the linearity between the three measurements and the true intake and independence between the three measurement errors. Limitations of this technique include the occurrence of Á > 1, known as "Heywood case", and the existence of negative correlations, which do not allow the calculation of Á. The objective of this review is to present the concept of the method, describe its application and examine the validation studies of dietary intake that use the triads method. We also conceptualize the "bootstrap" method, used to estimate the confidence intervals of the validity coefficients.

This paper describes a new food classification which assigns foodstuffs according to the extent and purpose of the industrial processing applied to them. Three main groups are defined: unprocessed or minimally processed foods (group 1), processed culinary and food industry ingredients (group 2), and ultra-processed food products (group 3). The use of this classification is illustrated by applying it to data collected in the Brazilian Household Budget Survey which was conducted in 2002/2003 through a probabilistic sample of 48,470 Brazilian households. The average daily food availability was 1,792 kcal/person being 42.5% from group 1 (mostly rice and beans and meat and milk), 37.5% from group 2 (mostly vegetable oils, sugar, and flours), and 20% from group 3 (mostly breads, biscuits, sweets, soft drinks, and sausages). The share of group 3 foods increased with income, and represented almost one third of all calories in higher income households. The impact of the replacement of group 1 foods and group 2 ingredients by group 3 products on the overall quality of the diet, eating patterns and health is discussed.

The Brazilian dietary guidelines are based in part on mainstream United States' recommendations, in spite of the criticisms and shortcomings of the American guidelines. In this paper, Brazilian food guidelines are summarized and discussed in comparison with the USA recommendations. American and Brazilian dietary recommendations are quite similar in many aspects, particularly those related to variety in the diet, the importance of physical activity and weight management. Different to American guidelines, those from Brazil advise people to choose fresh foods, to prefer healthier types of fat, to limit trans fat intake and to eat good sources of protein, but does not recommend the consumption of whole grains. Besides the challenges related to their implementation, indicators for the evaluation of the effectiveness of these guidelines should be established from the beginning, particularly those related to changes in dietary habits and the prevalence of obesity.

This study describes the validity of a food frequency questionnaire (FFQ) in 93 low-income women (20-65 years), participating in a case-control study in São Paulo, Brazil. Two FFQ (FFQ1 and FFQ2, 12 months apart) and three 24-hour dietary recalls (24hR) were conducted between 2003 and 2004 to estimate dietary intake during the past year. The Pearson correlation coefficients (crude, energy-adjusted and de-attenuated) were used for comparisons between FFQ and 24hR. The agreement between the methods was further examined by the Bland-Altman analysis. For the assessment of long-term reliability, the energy-adjusted intra-class correlation coefficients were mostly around 0.40, but higher for vitamin A and folate (0.50-0.56). Energy-adjusted, attenuation-corrected Pearson validity correlations between FFQ and DR ranged from 0.30-0.54 for macronutrients to 0.20-0.48 for micronutrients, with higher value for calcium (0.75). There were small proportions of grossly misclassified nutrient intakes, while Bland-Altman plots indicated that the FFQ is accurate in assessing nutrient intake at a group level.

This study assessed the validity of a food frequency questionnaire (FFQ-Porto Alegre), covering 135 food items, in comparison with the average of two consecutive 24-hour dietary recall questionnaires for adolescents, adults, and elderly who were randomly selected from a population-based survey. The Pearson correlation coefficients and cross-classification by quartiles of intake were used. The nutrients were log transformed and energy adjusted. The mean of adjusted de-attenuated correlation coefficient for adolescents was 0.44 and ranged from 0.18 (zinc) to 0.69 (folate) and for adult and elderly participants they were, respectively, 0.42, ranging from 0.16 (iron) to 0.73 (energy) and 0.52, ranging from 0.25 (vitamin E) to 0.84 (energy). The average classification percentage into the same or adjacent quartile for the two methods was 74.6% for adolescents, 74.9% for adults, and 81.2% for the elderly population. The FFQ showed fair relative validity for adolescents and adults, and may be used to study the dietary determinants of obesity and non-transmissible diseases in epidemiological surveys.

The study aims to describe and compare two methods of energy intake assessment and one measure of energy expenditure applied in adolescents from a birth cohort. In a sub-sample of the 1993 Pelotas (Brazil) birth cohort, followed up in 2006-7, information on intake was obtained through a food-frequency questionnaire (FFQ) and three 24-hour-recalls (24hR), while energy expenditure was assessed using an accelerometer. Bland &amp; Altman plots were used in the analyses in order to compare the methods. The mean difference between FFQ and 24hR was 592 ± 929cal/day. Compared to energy expenditure, intake was overestimated when measured by FFQ (357 ± 968cal/day) and underestimated by 24hR (-278 ± 714cal/day). In spite of the great differences between energy intake obtained using the two methods, lower differences were observed when these methods were compared to expenditure.

The aim of this study was to validate the intake of carotenoids, fruits and vegetables estimated by the Food Frequency Questionnaire for Adolescents (FFQA) using the method of triads. Blood samples were collected from 80 elementary school adolescents to assess serum levels of β-carotene. Partial correlation coefficients (r) were calculated between an estimated intake of carotenoids, fruits and vegetables and the serum levels of β-carotene. Validity coefficients were calculated using the method of triads. With the exception of carotenoids, partial r from the food frequency questionnaire (FFQ) were greater than those of the 24-hour recall (24hR). The fruit/vegetable group showed the highest partial r for the FFQ (r = 0.235) and the 24hR (r = 0.137). The highest validity coefficient was obtained for the vegetable group, as assessed by the FFQ (r = 0.873). On average, the validity coefficient values for the FFQ were greater than those obtained for the 24hR or the β-carotene serum levels. The FFQA is an accurate tool for estimating the intake of carotenoids, fruits and vegetables in this population group.

For dietary intake assessments, one needs to know the minimum 24-hour recall or food record replications that are required to estimate usual energy and nutrient intake and to classify subjects correctly according to their nutrient intake. Data from two different studies on dietary intake that were carried out with 300 adults and 169 adolescents in the Rio de Janeiro Metropolitan area, Brazil, were analyzed. To estimate the number of replications two methods were applied: one based on the variances ratio, the other based on the within-subject variance alone. The most important results found were the requirement for 14 replications for boys and men, 15 for girls, and 23 for women in order to estimate energy intake with a precision of 90%. Also four replications for boys and seven for men, girls and women are required to classify individuals' energy intake with a correlation coefficient of 0.9. Due to the within variance in food intake, a larger number of replications is required to obtain estimates of usual intakes than is needed to classify subjects according to levels of dietary intake.

The aim of this study was to investigate the effect of protein intake during pregnancy on postpartum weight variation. This was a prospective cohort study with 421 women interviewed at 15 days (baseline) and 2, 6, and 9 months postpartum. Data on diet were obtained using the food frequency questionnaire, focusing on the second and third trimesters. Protein intake was considered adequate when women consumed &gt; 1.2g of protein per kg body weight, and inadequate when < 1.2g/kg. The study adopted the mixed effects model for repeated measurements over time. The results showed a mean postpartum weight loss of 0.409kg/month (±0.12) (p < 0.01). Women with adequate protein intake during pregnancy lost an additional 0.094kg/month (±0.04) during postpartum (p = 0.03) when compared to women with inadequate intake. The model was adjusted for energy, % body fat, stature, age, schooling, skin color, and smoking. Recommended protein intake during pregnancy favored postpartum weight reduction.

This study aimed to develop a diet quality index (DQI-a) adjusted for energy requirement. Dietary intake of adults was assessed using 24-hour food recall. The DQI was developed for scores evenly distributed across ten items characterizing different aspects of diet: food groups, nutrients, and variety. The components categorized under the food groups from the Dietary Guide for Brazilians were adjusted according to the estimated energy requirements of the population studied. Index consistency and correlation with nutrients of the diet was analyzed by Cronbach's alpha. A total of 737 individuals were assessed and energy requirements ranged from 1,800 to 2,500kcal among women and 2,500 to 3,400kcal in men. The food group with greatest variation in total portions was cereals and tubers. Cronbach's alpha of the DQI-a was 0.643 and the index correlated with most of the nutrients. The DQI-a can be considered a valuable instrument for assessing diet quality of the Brazilian population.

The aim of the current study was to describe the sources of variation of energy and nutrient intake and to calculate the number of repetitions of diet measurements to estimate usual intake in adolescents from São Paulo, Brazil. Data was collected using 24-hour dietary recalls (24hR) in 273 adolescents between 2007 and 2008. Individuals completed a repeat 24hR around two months later. The sources of variation were estimated using the random effect model. Variance ratios (within-person to between-person variance ratio) and the number of repetitions of 24hR to estimate usual intake were calculated. The principal source of variation was due to within-person variance. The contribution of day of week and month of year was less than 8%. Variations ranged from 1.15 for calcium to 7.31 for vitamin E. The number of 24hR repeats required to estimate usual intake varied according to nutrient and gender, numbering 15 for males and 8 for females.

This work aimed to compare the results of three statistical methods applied in the identification of dietary patterns. Data from 1,009 adults between the ages of 20 and 65 (339 males and 670 females) were collected in a population-based cross-sectional survey in the Metropolitan Region of Rio de Janeiro, Brazil. Information on food consumption was obtained using a semi-quantitative food frequency questionnaire. A factor analysis, cluster analysis, and reduced rank regression (RRR) analysis were applied to identify dietary patterns. The patterns identified by the three methods were similar. The factor analysis identified "mixed", "Western", and "traditional" eating patterns and explained 35% of the data variance. The cluster analysis identified "mixed" and "traditional" patterns. In the RRR, the consumption of carbohydrates and lipids were included as response variables and again "mixed" and "traditional" patterns were identified. Studies comparing these methods can help to inform decisions as to which procedures best suit a specific research scenario.

The aim of the present study was to introduce Focused Principal Component Analysis (FPCA) as a novel exploratory method for providing insight into dietary patterns that emerge based on a given characteristic of the sample. To demonstrate the use of FPCA, we used a database of 1,968 adults. Food intake was obtained using a food frequency questionnaire covering 26 food items. The focus variables used for analysis were age, income, and schooling. All analyses were carried out using R software. The graphs generated show evidence of socioeconomic inequities in dietary patterns. Intake of whole-wheat foods, fruit, and vegetables was positively correlated with income and schooling, whereas for refined cereals, animal fats (lard), and white bread this correlation was negative. Age was inversely associated with intake of fast-food and processed foods and directly associated with a pattern that included fruit, green salads, and other vegetables. In an easy and direct fashion, FPCA allowed us to visualize dietary patterns based on a given focus variable.

We describe the use of factor analysis for assessing food habits in Japanese-Brazilians. Dietary data from 1,283 participants of a cross-sectional study were used. Besides statistical criteria, we also used the conceptual meaning of identified profiles to obtain scores for dietary patterns (Japanese or Western profile). Paired Student t test, linear regression and Poisson models were used to verify the existence of relationship between these scores and generation, body mass index (BMI), waist circumference and presence of metabolic syndrome, respectively. First generation subjects had higher mean Japanese profile scores and lower Western profile scores than those of second generation. The Western dietary pattern was associated with BMI (p = 0.001), waist circumference (p = 0.023) and metabolic syndrome (p < 0.05). We concluded that these scores were able to discriminate subjects who maintained their traditional Japanese lifestyle or otherwise, and that the incorporation of a Western lifestyle is associated to high values of BMI, waist circumference and presence of metabolic syndrome.

Information on fruits and vegetables consumption in Brazil in the three levels of dietary data was analyzed and compared. Data about national supply came from Food Balance Sheets compiled by the FAO; household availability information was obtained from the Brazilian National Household Budget Survey (HBS); and actual intake information came from a large individual dietary intake survey that was representative of the adult population of São Paulo city. All sources of information were collected between 2002 and 2003. A subset of the HBS, representative of São Paulo city, was used in our analysis in order to improve the quality of the comparison with actual intake data. The ratio of national supply to household availability of fruits and vegetables was 2.6 while the ratio of national supply to actual intake was 4.0. The discrepancy ratio in the comparison between household availability and actual intake was smaller, 1.6. While the use of supply and availability data has advantages, as lower cost, must be taken into account that these sources tend to overestimate actual intake of fruits and vegetables.

The objective of this study was to investigate the effect of seasonality on nutrient intake in healthy adults from the southernmost metropolitan area of Brazil. The dietary intake (24-hour dietary recall on six different days) in a sample of 162 adults (114 women), aged 20 to 69, was obtained during the year 2007. The nutrient intake was averaged for each season and adjusted for energy intake using the residual method. The effect of season on energy, macro and micro-nutrient intake was investigated based on the Generalized Estimate Equations (GEE) model. There were statistically significant differences between seasons for carbohydrate and total fat intake after controlling for gender, age, education, and interactions. In summer carbohydrate intake was higher than other seasons while the total fat intake was lower. These findings highlight the importance of considering seasonal variations not only for evaluating dietary intake but also nutrition and public health policy recommendations, particularly in adult populations living in temperate regions.

This study aims to estimate an adult-equivalent scale for calorie requirements and to determine the differences between adult-equivalent and per capita measurements of calorie availability in the Brazilian population. The study used data from the 2002-2003 Brazilian Household Budget Survey. The calorie requirement for a reference adult individual was based on the mean requirements for adult males and females (2,550kcal/day). The conversion factors were defined as the ratios between the calorie requirements for each age group and gender and that of the reference adult. The adult-equivalent calorie availability levels were higher than the per capita levels, with the largest differences in rural and low-income households. Differences in household calorie availability varied from 22kcal/day (households with adults and an adolescent) to 428kcal/day (households with elderly individuals), thus showing that per capital measurements can underestimate the real calorie availability, since they overlook differences in household composition.

With the purpose of generating a list of foods for a food-frequency questionnaire, data from 24h dietary recalls on a typical day from a probabilistic sample of 1,724 adults of Niterói, Rio de Janeiro, Brazil, were analyzed. The frequency of food intake, the total intake of energy and macronutrients and the relative contribution of each food item to total energy and macronutrient intake were calculated. The most frequently reported food items (> 50% of adults) were rice, coffee, beans, refined canesugar, and bread. Whole milk was consumed more frequently then skimmed milk or semi-skimmed milk. Beef was consumed by more adults than chicken, pork or fish. Approximately 90% of energy and macronutrients intake was explained by 65 food items. The list of food items generated in the present analysis is similar to those found in other samples of adults from urban areas in Brazil. It may be possible to generate a core list of common foods with addition of regional foods to be used nationally in urban areas of the country.