Introduction: Statistical methods such as Principal Component Analysis (PCA) and Factor Analysis (FA) are increasingly popular in Nutritional Epidemiology studies. However, misunderstandings regarding the choice and application of these methods have been observed. Objectives: This study aims to compare and present the main differences and similarities between FA and PCA, focusing on their applicability to nutritional studies. Methods: PCA and FA were applied on a matrix of 34 variables expressing the mean food intake of 1,102 individuals from a population-based study. Results: Two factors were extracted and, together, they explained 57.66% of the common variance of food group variables, while five components were extracted, explaining 26.25% of the total variance of food group variables. Among the main differences of these two methods are: normality assumption, matrices of variance-covariance/correlation and its explained variance, factorial scores, and associated error. The similarities are: both analyses are used for data reduction, the sample size usually needs to be big, correlated data, and they are based on matrices of variance-covariance. Conclusion: PCA and FA should not be treated as equal statistical methods, given that the theoretical rationale and assumptions for using these methods as well as the interpretation of results are different.

The use of dietary patterns (DP) in nutritional research is well established; however, only a few studies of DP according to specific meals have been conducted. The purpose of this study was to identify the DP regarding breakfast, lunch and dinner meals of the population (aged 20 years and older of both sexes) that participated in the Health Care Survey of Sao Paulo. Food intake was estimated by using the Multiple Source Method - considering two 24- h dietary recalls. On the basis of the food groups for each meal, a factor analysis, with a principal component estimation, was applied (varimax rotation) in order to derive the DP. Prevalences of meal skipping were 5·6 % for breakfast, 3·6 % for lunch and 12·8 % for dinner. The findings revealed three breakfast DP: healthy, traditional and snack; five lunch DP: traditional, salad, sweetened juice, Western and meats; and four dinner DP: coffee with milk and bread, transitional, traditional, and soup and fruits. The results of this study indicate that the DP identified in accordance with the meal nicely discriminates food intake, emphasising peculiarities that are not found in global analyses and might support dietary advice.

The objective was to investigate the relationships between body mass index (BMI), skipping breakfast, and breakfast patterns in Brazilian adults. We analyzed data of 21,003 individuals aged between 20 to 59 from the Brazilian National Dietary Survey 2008-2009. Breakfast was defined as the eating occasion between 5 and 10a.m. with the highest usual food consumption (exceeding 50Kcal/209.2kJ). Dietary patterns were derived by the factor analysis of 18 food groups (usual intake). Controlling for confounders linear regressions of BMI were used to verify the associations considering the survey design. Skipping breakfast was not associated with BMI. Three breakfast patterns were observed (48% variability): Brazilian Northern (positive loading for meats, preparations with corn, eggs, tubers/roots/potatoes, dairy products, savory snacks/crackers, fruit juices/fruit drinks/soy-based drinks); Western (positive for fruit juices/fruit drinks/soy-based drinks, sandwiches/pizza, baked/deep-fried snacks, chocolate/desserts, cakes/cookies) and Brazilian Southeastern (cold cut meat, milk, cheese, coffee/tea, bread). The Brazilian Southeastern pattern was inversely associated with BMI, while the Brazilian Northern pattern was directly associated with it. Therefore, the results suggest a role for breakfast quality in the association with BMI. Thus, a Brazilian Southeastern breakfast usual intake may be inversely associated with BMI.

BackgroundThe association of obesity and dietary patterns has been well documented in scientific literature; however, information on the impact of meal patterns on obesity is scarce. The objective of this study was to investigate the association of adherence to lunch patterns and body mass index (BMI) in a representative sample of individuals aged 20 years or older in Sao Paulo.MethodsData for 933 participants were retrieved from the Health Survey of São Paulo (ISA-Capital 2008), a cross-sectional population-based survey. The usual dietary intake of individuals with at least one 24-h recall was estimated by the Multiple Source Method. The definition of lunch was self-reported by the participant. Five lunch patterns were derived from twenty-two food groups by exploratory factor analysis: Traditional, Western, Sweetened juice, Salad, and Meats. To estimate the effect of lunch patterns on BMI, we used a generalized linear model with link identity and inverse Gaussian distribution. Analyses were adjusted by age, gender, household income per capita, physical activity levels, smoking status, alcohol consumption, total energy intake, and misreporting status.ResultsThe greater adherence to the traditional pattern at the lunch meal was associated with lower BMI, only in insufficiently active individuals (ß = −0.78; 95% CI -1.57; −0.02).ConclusionsThe traditional Brazilian lunch pattern might protect the insufficiently active individuals against obesity.

Objectives. To analyze trends in cigarette smoking among Brazilian adults from 2006 to 2019. Methods. We performed a time-series analysis based on data from the Surveillance of Risk and Protective Factors for Chronic Diseases Telephone Survey (n = 730 309). We calculated the annual prevalence of current cigarette smokers, heavy smokers, and passive smokers in the workplace and investigated linear trends using Prais–Winsten regression, for the entire period and for the past 5 years. We performed the analyses for the total population and according to the sociodemographic characteristics. Results. The prevalence of cigarette smoking, heavy smoking, and passive smoking in the workplace declined, respectively, an average of 3.99% per year, 5.65% per year, and 6.55% per year from 2006 to 2019. We observed this reduction regardless of gender, age, educational level, and geographic region. The magnitude of reduction in the prevalence of current cigarette smoking decreased in the past 5 years, while the magnitude of the change in heavy smoking increased. Conclusions. The prevalence of cigarette smoking decreased in the time period studied. The smaller magnitude of reduction for current cigarette smoking in the most recent years might indicate a fatigue with the current policy scenario. (Am J Public Health. Published online ahead of print February 18, 2021: e1–e9. https://doi.org/10.2105/AJPH.2020.306102 )

The objective of this study was to assess the quality of lunch consumed by adults in Brazil and its sociodemographic determinants in each Brazilian region. A cross-sectional study was carried out and a representative sample of regional populations was used. The sample comprised of 16,096 adults from the Brazilian National Dietary Survey, part of the Brazilian Household Budget Survey (POF). The lunch quality was evaluated by applying the main meal quality index (MMQI), comprised of 10 items of equal weights that resulted in a score that ranged from zero to 100 points. Linear regression models measured the association between lunch quality and sociodemographic factors. The average energy consumption at lunch was 704kcal (SD = 300), and the meal quality score mean was 57 points (SE = 0.30). The North Region had the worst MMQI score (56 points, SE = 0.07), while the Central had the best MMQI adjusted score (59 points, SE = 0.05). The MMQI final score was positively associated with male gender and ages between 20-39 years, and was inversely associated with having eight years or more of education, per capita income of at least three minimum wages, and with the consumption of meals prepared away from home. Despite differences among sociodemographic factors, all Brazilian regions had a lunch composed of foods rich in sugars and fats, with insufficient portions of fruits and vegetables, resulting in a low meal quality.

Resumo Objetivo Analisar a tendência temporal das prevalências de excesso de peso e obesidade nas capitais brasileiras e no Distrito Federal, 2006-2019. Métodos Série temporal, sobre dados do Sistema de Vigilância de Fatores de Risco e Proteção para Doenças Crônicas por Inquérito Telefônico (n=730.309). Analisaram-se as prevalências de excesso de peso e obesidade para cada ano, segundo a combinação de sexo, faixas etárias e níveis de escolaridade. A variação temporal foi analisada por regressão de Prais-Winsten. Resultados Observaram-se variações das prevalências de excesso de peso, principalmente em homens com 18-24 anos de idade e até 8 anos de estudo (3,17%/ano), e em mulheres de 18-24 anos e ≥12 anos de estudo (6,81%/ano). Observaram-se variações na prevalência de obesidade, principalmente entre mulheres de 18-24 anos e escolaridade ≥12 anos (10,79%/ano). Conclusão Verificou-se aumento do excesso de peso e obesidade na maioria dos estratos sociodemográficos, especialmente entre jovens de maior escolaridade.

Examine the composition of breakfast concerning weight status is essential for evaluating adolescent health and understanding this gap. This study aimed to identify breakfast patterns and investigate the relationship with weight status among Brazilian adolescents. We used a subsample of 7,425 adolescents aged 10-19 years from the 2008-2009 Brazilian Household Budget Survey. Breakfast eaters were those with intake of at least 50 kcal (209.2kJ) between 5 and 10 a.m. Breakfast dietary patterns were derived by principal component factor analysis with varimax rotation. We performed logistic regression analyses between breakfast patterns and weight status, considering the complexity of the survey sample design. Three breakfast patterns were identified explaining 44.8% of data variability: (1) the Cereal, protein, fruit beverages and Northern/Northeastern pattern, characterized by high consumption of cookies, meats, dairy products, preparations with corn, eggs, fruit juices/fruit drinks/soy-based drinks, tubers/roots/potatoes, and cereals, and negative adherence to cold cut meat and savory snacks/crackers; (2) the Protein-based pattern, characterized by positive loadings for cold cut meat, milk and cheese, and negative for cookies, fruit juices/fruit drinks/soy-based drinks, tubers/roots/potatoes, and cereals; and (3) the Mixed pattern, with positive loadings for cakes, coffee/tea, bread, fruit juices/fruit drinks/soy-based drinks, chocolate/desserts, and savory snacks/crackers. No association was found between skipping and weight status. Overweight adolescents had lower adherence to the Cereal, protein, fruit beverages and Northern/Northeastern pattern pattern (OR=0.67; 95% CI 0.47; 0.96). This is the first study to address dietary patterns at the meal level with adolescent population-based data, which requires further investigation.