Trends in the prevalence of obesity, overweight, and thinness among schoolchildren aged 7-14 years from southern Brazil (2002-2019).

OBJECTIVE: To analyze the obesity, overweight, and thinness trends among Brazilian schoolchildren by sex, age group, and type of school according to World Health Organization (WHO) and International Obesity Task Force (IOTF) criteria. METHODS: We conducted four surveys between 2002 and 2018/19 involving schoolchildren aged 7-14 years from a state capital in southern Brazil. Weight status was classified using both WHO and IOTF criteria. RESULTS: In the total sample, obesity prevalence based on the IOTF and the WHO criteria were 72% and 44% higher in 2018/19 compared with 2002, respectively. Over the whole period, the obesity prevalence increased among children (WHO: 10.1% vs. 14.1%; IOTF: 5.0% vs. 8.3%), and those from public schools (WHO: 10.5% vs. 16.4%; IOTF: 5.6% vs. 10.1%). There was no significant reduction in thinness prevalence over the analyzed period. CONCLUSION: Obesity prevalence remains on an upward trend in a state capital in southern Brazil, especially among children from public schools. A higher prevalence of overweight and obesity was observed using the WHO criteria compared with IOTF criteria.

Changes in total and central adiposity and body fat distribution among 7-10-year-old schoolchildren in Brazil.

OBJECTIVE: To describe changes in total and central adiposity and body fat distribution in children over a 5-year period by investigating variations in BMI, waist circumference (WC), waist-to-height ratio (WHtR) and skinfold thicknesses (SFT). DESIGN: A school-based sample of children from 2nd to 5th grades of elementary schools participated in two cross-sectional studies in 2002 (n 2936) and 2007 (n 1232). SETTING: Public and private schools of Florianopolis, Brazil. SUBJECTS: Schoolchildren aged 7-10 years had their weight, height, WC and SFT measured according to standard procedures. Body fat distribution was assessed by triceps, subscapular, suprailiac and medial calf skinfold measurements. Changes in BMI, WC, WHtR and SFT were analysed, adjusting for type of school and monthly family income. RESULTS: Adjusted mean differences between 2002 and 2007 for BMI and WC were always positive and of similar magnitude between boys and girls. However, a statistically significant increase was observed only for BMI (raw and Z-score values) in boys. WHtR remained stable in both sexes. Adjusted median values for SFT also increased in boys and girls, except for triceps skinfold. BMI, WC and SFT tended to increase across age classes in both sexes. The relative change observed for the median central skinfolds (subscapular and suprailiac) was greater than that of peripheral skinfolds (triceps and medial calf). CONCLUSIONS: The subcutaneous adipose tissue (SFT) appeared to increase at a faster rate than total adiposity (BMI). The increase in central SFT indicates that the relative change is due primarily to a rise in central adiposity.

Trends in adiposity in Brazilian 7-10-year-old schoolchildren: evidence for increasing overweight but not obesity between 2002 and 2007.

BACKGROUND: The negative health consequences of childhood overweight/obesity (OW/OB) are well known. Therefore, an accurate monitoring of the OW/OB prevalence is essential. Anthropometry is the most practical and cost-effective method for nutritional status evaluation. AIM: To describe trends in the nutritional status among 7-10-year-old children by investigating changes in the prevalence of stunting, thinness, overweight, obesity, risk and excess abdominal adiposity, and to study changes in height-for-age, body mass index (BMI) and waist circumference (WC). SUBJECTS AND METHODS: A school-based sample of 7-10-year-old children participated in two cross-sectional studies in 2002 (n = 2936) and 2007 (n = 1232) in Florianopolis, southern Brazil. Prevalence of stunting, risk and excess abdominal adiposity and changes in the distribution of height-for-age, BMI-for-age, WC-for-age z-scores were evaluated. Three BMI-based references were used to define the prevalence of thinness, overweight and obesity. RESULTS: Between 2002-2007, the prevalence of stunting, thinness, obesity and excess abdominal adiposity remained stable, whereas overweight (including obesity) increased 10-23% in boys and 18-21% in girls, depending on the BMI reference used. The risk of abdominal adiposity increased in boys, but not in girls. No significant change was observed in mean height, BMI, WC-for-age z-scores. CONCLUSIONS: This study identified a potential levelling off in the prevalence of obesity and excess abdominal adiposity, but a continuing increase in the prevalence of overweight.

Methodological aspects and characteristics of participants in the study on the prevalence of obesity in children and adolescents in Florianópolis, Southern Brazil, 2018-2019: EPOCA study.

PURPOSE: To describe the methodological aspects and characteristics of the participants of the EPOCA survey. METHODS: The study was conducted with schoolchildren aged between seven to 14 years old from 30 schools in Florianópolis, Southern Brazil. Body mass, height, girths, and skinfold thicknesses were measured. Food consumption and physical activity from the previous day were self-reported using the validated Web-CAAFE questionnaire. Adolescents completed a specific questionnaire about physical activity, meal consumption, and weight control behaviors. Parents/guardians responded to a sociodemographic and habits questionnaire. RESULTS: A total of 1671 schoolchildren participated in the study (response rate: 27.2%). About 63% of schoolchildren were enrolled in public schools. Most studied in the morning shift (54.2%), were female (53.1%) and aged between seven and 10 years (58.1%). The prevalence of overweight was 33.7% and obesity was 11.3%. CONCLUSIONS: The data obtained will allow us to assess the trend in the prevalence of overweight and obesity and associated factors when compared to other surveys performed. Descriptions of the logistics and protocols can help in the development and improvement of similar studies. It is hoped that the results of EPOCA 2018/2019 may help in the design of obesity prevention policies and programs for this population.

Food consumption and its association with leisure-time physical activity and active commuting in Brazilian workers.

BACKGROUND/OBJECTIVES: An in-depth understanding of the relationship between food consumption and physical activity is relevant since these behaviours could influence each other, while both have an effect on obesity and chronic diseases. In this context, the aim of this study was to investigate the effect of various combinations of food consumption (fruits, vegetables, sweets and snacks) on the associations with PA domains (leisure and commute) among Brazilian industrial workers. SUBJECTS/METHODS: This is part of a cross-sectional national survey developed in Brazil using data from the "Lifestyle and Leisure Habits of Industrial Workers" project. A total of 52,774 workers (response rate: 90.6%) responded to a validated questionnaire about the frequency of their consumption of fruit, vegetables, sweets and snacks, their practice of LTPA and active commuting. The answers were analysed by multilevel regression, controlled by sociodemographic behaviour and the presence of hypertension, diabetes and overweight. RESULTS: Workers with a simultaneously adequate consumption of fruit, vegetables, sweets and snacks were 2.29 (1.74; 2.99 p-value < 0.001) more likely to perform LTPA. In the full model, there was no association among any of the combinations of food consumption and active commuting. CONCLUSION: A better food consumption behaviour was reported among workers who practiced leisure physical activity when compared to those who did not.

Empirically derived dietary patterns through latent profile analysis among Brazilian children and adolescents from Southern Brazil, 2013-2015.

The aims of this study were to identify dietary patterns (DPs) of children and adolescents participating in three cross-sectional surveys (2013-2015) and to test their associations with sociodemographic variables, physical activity (PAS), screen-based sedentary activity (SA), and weight status. One-day data were obtained from 5,364 schoolchildren (7-12 years) from public schools of Florianopolis (South of Brazil), using the validated questionnaire Web-CAAFE (Food Intake and Physical Activity of Schoolchildren). DPs were derived from the frequency of daily consumption of 32 foods/beverages by latent profile analysis. Multinomial logistic regression analysis was used to estimate the association of the DPs with sociodemographic variables, physical activity, screen activity and weight status. 'Traditional', 'Monotonous', and 'Mixed' DPs were identified. The percentages of children and adolescents within these profiles were 41.3, 36.3, and 22.4%, respectively. Children and adolescents in the highest tertiles of both PAS and daily frequency of SA had a higher probability to present a 'Mixed' DP compared to peers with less PAS and SA. Children and adolescents who reported having a school meal were significantly more likely to present the 'Traditional'DP, while boys who did not report having a school meal had a higher probability to present the 'Monotonous' DP. The DPs were not associated with the year of survey, age, family income, or weight status.

Individual characteristics and public or private schools predict the body mass index of Brazilian children: a multilevel analysis.

The aim of this study was to determine the contribution of individual and school characteristics to the variability in body mass index (BMI) z-scores of 7 to 10 years old children. Anthropometric and sociodemographic data from two cross-sectional studies conducted with schoolchildren from the 2nd to the 5th grades of elementary schools were analyses (n = 2,936 in 2002, and n = 1,232 in 2007). Multilevel modeling was used to estimate variations in BMI at child and school levels. The contribution of the school context to the overall variability of BMI z-score was small but significant in 2002 (3.3%-4.4%) and in 2007 (2.4%-5.3%), showing that schoolchildren from private schools had a higher BMI compared to those from public schools. The monthly family income showed, in general, a negative association with BMI z-score in 2002 and a positive association in 2007, for both sexes. The consumption of sweets showed a negative effect in the BMIs of children. In both surveys, overweight/obese mothers and excessive birth weight were positively associated with BMI z-score. Mother's weight status had a higher influence on the overall variability of BMI in both surveys. In conclusion, school and child characteristics contributed to the variance in children's weight status. The results imply that overweight/obesity childhood prevention programs should focus on strategies of family engagement to be more effective.

Avaliação de programa de atividade física para escolares: desenvolvimento e validação de instrumento / Evaluation of physical activity program for students: development and validation of an instrument

Este estudo objetiva desenvolver e validar um instrumento para avaliar dimensões do planejamento e processo de implementação de um programa de intervenção voltado à promoção de atividade física em escolares. Foi conduzido um estudo metodológico realizado durante os meses de julho a dezembro de 2016, vinculado ao programa de intervenção intitulado de "Movimente". O estudo envolveu as fases teórica (construção do instrumento), empírica e analítica (validação de conteúdo por especialistas, com atribuição de pontuação para os itens e de semântica, por membros da comunidade escolar e alunos do 7º ao 9º ano). O instrumento é dividido em duas dimensões: planejamento e processo. Resultados mostram que a dimensão de planejamento foi composta por indicadores acerca da importância da discussão sobre temas de saúde no contexto escolar, interesse em participar do programa e de suas respectivas ações. A dimensão de processo englobou indicadores sobre conhecimento e avaliação do programa e de suas respectivas ações, bem como sobre o interesse em manter o mesmo. Todas as questões foram consideradas válidas (índices de validade acima de 0,90) e compreensíveis (escores acima de 0,82). Conclui-se que o instrumento apresentou qualidade satisfatória no que diz respeito a validade de conteúdo e semântica, sendo considerado apropriado para avaliação do Programa Movimente e programas e ou projetos similares

This study aims to develop and validate an instrument that evaluates dimensions of planning and im-plementation of an intervention program focused on physical activity promotion in schoolers. It was conducted a methodological study carried out during the months of July to December of 2016, part of the Movimente Program. The study included theoretical (instrument development), empirical and analytical phases (content validadion by specialists, with scores atribution to each item, and by par-ticipants with characteristics similar to those of the target population, including school community, and students from 7th to 9th grade school). The instrument is composed by two dimensions: planning and process. Results show that planning was composed by indicators related to the importance of discussing health topics on the school context; interest in take part of the Program and its respective actions. Dimension included indicatos related to awaraness and evaluation program, and interest on program maintenance. All questions were considered valid (validation scores greater then 0.90) and with a good semantic (scores greated than 0.82). In conclusion, the instrument showed a reasonable quality regarding semantic and content validity, being considered apropriate for evaluation of Movi-mente Program and similar programs of physical activitiy programs in schoolers

Performance of references based on body mass index for detecting excess body fatness in schoolchildren aged 7 to 10 years.

OBJECTIVE: To compare the sensitivity and specificity of body mass index (BMI)-based classification systems and to determine the optimal cut-offs for predicting excess body fatness in schoolchildren. METHODS: 2795 schoolchildren aged 7 - 10 years were examined. Excess body fatness was defined as the standardized residuals of the sum of three skinfold thickness ranking at or above the 90th percentile. The international BMI-based system recommended by the World Health Organization (WHO-2007) was evaluated on the basis of its sensitivity and specificity for detecting excess body fatness and compared with a national BMI reference (Brazil-2006). Likelihood ratios analysis was used to select the optimal cut-offs in each curve. RESULTS: The two classification systems presented high sensitivity (92.5 - 98.6%) and moderate specificity (75.9 - 85.0%) for both sexes. The optimal BMI cut-offs improved specificity with no marked loss of sensitivity. Using the proposed BMI cut-offs, the post-test probability of predicting excess body fatness for children classified as non-overweight decreased from 10 (pre-test probability) to 1.4% in girls and to 1.1% in boys. For overweight children, this probability increased to more than 46.0%. CONCLUSION: The results showed that both the WHO-2007 and Brazil-2006 classification systems can be used as screening instruments for excess body fatness, and that one of the limitations of using the BMI-for-age references could be improved by refining the existing cut-offs.

Diagnostic accuracy of anthropometric indices in predicting excess body fat among seven to ten-year-old children.

PURPOSE: To evaluate the accuracy of the body mass index (BMI), waist circumference (WC) and waist-to-height ratio (WHtR) in detecting excess body fat among schoolchildren in Florianópolis, Santa Catarina. METHODS: Cross-sectional study with 2,772 schoolchildren aged seven to ten years. Receiver Operating Characteristic (ROC) curves were used to compare the diagnostic accuracy of the BMI, the WC and the WHtR in identifying children with excess body fat (defined as values that were equal to or higher than the 90th percentile of the standardized residuals obtained from the sum of the four skinfolds thickness). Likelihood ratio estimates were used to select, for each anthropometric index, the cut-off points that presented the highest association with excess body fat. RESULTS: The BMI, WC and WHtR performed well in detecting excess body fat, indicated by areas under the ROC curve (AUC) close to 1.0, with slightly higher AUC for the BMI in comparison to the WC and the WHtR concerning both sexes. Highly sensitive and specific cut-off points were derived for the three anthropometric indices. Sensitivity ranged from 85.7 to 92.9% for the BMI, from 78.6 to 89.7% for the WC, and from 78.6 to 89.2% for the WHtR. Specificity ranged from 83.2 to 91.4%, from 75.0 to 90.7%, and from 77.4 to 88.3% for the BMI, the WC and the WHtR, respectively. CONCLUSION: BMI, WC and WHtR can be used as diagnostic tests to identify excess body fat in children from seven to ten years of age.

Clustering of risk factors for non communicable diseases in adults from Florianopolis, SC.

OBJECTIVE: To investigate clustering patterns of health risk behaviors for non communicable diseases and its associated factors. METHODS: a Random telephone survey with 1,996 adults from Florianopolis, SC, was conducted in 2005. Tobacco use, high alcoholic intake episodes, fruit consumption and physical inactivity were investigated. Clustering was examined by the ratio between observed and expected prevalence of each of the 16 possible combinations. These clustered risk factors comprised the main outcome and binomial and multinomial logistic regression was conducted to examine socio-demographic correlates. RESULTS: 43% of men and 36.6% of women clustered at least two health risk factors. Three (19.2%; CI 95% 16.7 - 21.7) and five (9.8%; CI 95% 8.0 - 11.6) specific combinations exceed the expected prevalence, respectively, in men and women. Women with low schooling level and older were more likely to cluster health risk behaviors. CONCLUSION: although men showed higher prevalence of single health risk behavior and its combinations, women presented more specific combinations that clustered above the expected. Knowledge on the clustering pattern of these health risk behaviors may guide the design of more effective health promotion initiatives.

Individual characteristics and public or private schools predict the body mass index of Brazilian children: a multilevel analysis / Características individuais e tipo de escola predizem o índice de massa corporal das crianças brasileiras: uma análise multinível / Características individuales y escuelas públicas o privadas en la predicen el índice de masa corporal: un análisis multinivel

The aim of this study was to determine the contribution of individual and school characteristics to the variability in body mass index (BMI) z-scores of 7 to 10 years old children. Anthropometric and sociodemographic data from two cross-sectional studies conducted with schoolchildren from the 2nd to the 5th grades of elementary schools were analyses (n = 2,936 in 2002, and n = 1,232 in 2007). Multilevel modeling was used to estimate variations in BMI at child and school levels. The contribution of the school context to the overall variability of BMI z-score was small but significant in 2002 (3.3%-4.4%) and in 2007 (2.4%-5.3%), showing that schoolchildren from private schools had a higher BMI compared to those from public schools. The monthly family income showed, in general, a negative association with BMI z-score in 2002 and a positive association in 2007, for both sexes. The consumption of sweets showed a negative effect in the BMIs of children. In both surveys, overweight/obese mothers and excessive birth weight were positively associated with BMI z-score. Mother's weight status had a higher influence on the overall variability of BMI in both surveys. In conclusion, school and child characteristics contributed to the variance in children's weight status. The results imply that overweight/obesity childhood prevention programs should focus on strategies of family engagement to be more effective.

O estudo teve como objetivo medir a contribuição das características individuais do aluno e da escola à variabilidade dos escores-z do índice de massa corporal (IMC) em crianças brasileiras entre 7 e 10 anos de idade. Foram analisados dados antropométricos e sociodemográficos de dois estudos trnasversais conduzidos com escolares da segunda à quinta série de Ensino Fundamental (n = 2.936 em 2002 e n = 1.232 em 2007). A modelagem multinível foi utilizada para estimar as variações de IMC em nível individual e de escola. A contribuição do contexto escolar à variabilidade global do escore-z do IMC foi pequena, porém significativa, em 2002 (3,3%-4,4%) e em 2007 (2,4%-5,3%), mostrando que alunos de escolas particulares tinham IMC mais alto, comparado ao dos alunos de escolas públicas. A renda familiar mensal mostrou uma associação negativa com o escore-z do IMC em 2002 e uma associação positiva em 2007, para ambos sexos. O consumo de doces mostrou efeito negativo sobre o IMC das crianças. Em ambos estudos, filhos de mães com sobrepeso/obesidade e alunos com história de excesso de peso ao nascer mostraram associação positiva com o escore-z do IMC. Em ambos estudos, o estado nutricional materno mostrou influência maior sobre a variabilidade global do IMC. Em conclusão, as características da escola e do aluno contribuíram para a variância no IMC da criança. Os resultados sugerem que, para serem mais eficazes, os programas de prevenção de sobrepeso/obesidade na infância devem focar em estratégias com participação da família.

El objetivo de este estudio fue determinar la contribución de las características individuales y escolares en la variabilidad del índice de masa corporal (IMC) z-scores en niños de entre 7 a 10 años de edad. Se analizaron datos antropométricos y sociodemográficos de dos estudios transversales conducidos con escolares de la segunda a la quinta serie de la enseñanza fundamental (n = 2.936 en 2002 y n = 1.232 en 2007). Se utilizaron modelos multinivel para estimar variaciones en el IMC en los niveles infantiles y escolares. La contribución del contexto escolar para la variabilidad general de IMC z-score fue pequeña, pero significativa en 2002 (3,3%-4,4%) y en 2007 (2,4%-5,3%), indicando que los escolares de escuelas privadas tenían un IMC superior, comparados con los de las escuelas públicas. Los ingresos familiares mensuales mostraron, en general, una asociación negativa con el IMC z-score en 2002 y una asociación positiva en 2007, para ambos sexos. El consumo de dulces mostró un efecto negativo en el IMC de los niños. En ambas encuestas, las madres con sobrepeso/obesas y el peso excesivo al nacer se asociaron positivamente con el IMC z-score. El estatus del peso de la madre tuvo una influencia más alta en la variabilidad general del IMC en ambas encuestas. En conclusión, las características escolares y del niño contribuyeron a la variancia en el estatus de peso de los niños. Los resultados implican que los programas infantiles de prevención de sobrepeso/obesidad deberían enfocarse en estrategias de adhesión familiar para ser más efectivos.

[Changes in food consumption and physical activity in schoolchildren of Florianópolis, Southern Brazil, 2002-2007]. / Mudanças no consumo alimentar e atividade física de escolares de Florianópolis, SC, 2002-2007.

OBJECTIVE: To assess changes in food consumption and physical activity levels in schoolchildren. METHODS: A study was conducted with a representative sample (n = 4,168) of schoolchildren aged between seven and ten years living in the city of Florianópolis, Southern Brazil. Food consumption and physical activity were assessed in two school-based studies in 2002 (n = 2,936; 51% boys; mean age = 8.5 years) and 2007 (n = 1,232; 50.7% boys; mean age = 8.6 years), using illustrated questionnaires. The chi-square test was used to assess changes in the consumption of eight foods/food groups, in terms of the recommendations of the Brazilian Food Guidelines and physical activity levels (assessed according to tertiles of distribution of score and type of transportation to school). Analyses were performed according to the type of school attended (private or public). RESULTS: There was a reduction in the proportion of schoolchildren who reported eating fruits, vegetables, beans, meat, snack foods, pizza, French fries and sodas. A higher proportion of private school children met the recommendations that restricted the consumption of sodas, pizza and French fries and promoted the consumption of fruits and vegetables, in both studies. On the other hand, a higher proportion of public school children met the recommendations of meat consumption in 2007. Median values of scores of physical activity decreased in 2007. In both years, private school children were more active. The proportion of schoolchildren who actively commuted to school decreased from 49% to 41% (p < 0.01). CONCLUSIONS: There was a reduction in the consumption of markers of a healthy diet (beans, meat/fish, fruits and vegetables) and high-energy and low-nutrient foods (sodas, snack foods and pizza/French fries). In addition, there was a decrease in the proportion of schoolchildren who reported actively commuting to school.

Validation of the Online version of the Previous Day Food Questionnaire for schoolchildren / Validação da versão Online do Questionário Alimentar do Dia Anterior para Escolares

ABSTRACT Objective To evaluate the validity of the web-based version of the Previous Day Food Questionnaire Online for schoolchildren from the 2nd to 5th grades of elementary school. Methods Participants were 312 schoolchildren aged 7 to 12 years of a public school from the city of Florianópolis, Santa Catarina, Brazil. Validity was assessed by sensitivity, specificity, as well as by agreement rates (match, omission, and intrusion rates) of food items reported by children on the Previous Day Food Questionnaire Online, using direct observation of foods/beverages eaten during school meals (mid-morning snack or afternoon snack) on the previous day as the reference. Multivariate multinomial logistic regression analysis was used to evaluate the influence of participants' characteristics on omission and intrusion rates. Results The results showed adequate sensitivity (67.7%) and specificity (95.2%). There were low omission and intrusion rates of 22.8% and 29.5%, respectively when all food items were analyzed. Pizza/hamburger showed the highest omission rate, whereas milk and milk products showed the highest intrusion rate. The participants who attended school in the afternoon shift presented a higher probability of intrusion compared to their peers who attended school in the morning. Conclusion The Previous Day Food Questionnaire Online possessed satisfactory validity for the assessment of food intake at the group level in schoolchildren from the 2nd to 5th grades of public school.

RESUMO Objetivo Avaliar a validade da versão baseada na Internet do Questionário Alimentar do Dia Anterior (Online) para escolares do segundo ao quinto ano do ensino fundamental. Métodos Participaram do estudo 312 escolares de 7 a 12 anos de uma escola pública de Florianópolis, Santa Catarina. A validade foi testada pela sensibilidade, especificidade e taxas de concordância (acertos, omissões e intrusões) dos itens alimentares relatados no Questionário Alimentar do Dia Anterior Online, usando a observação direta dos alimentos consumidos no lanche escolar do dia anterior como padrão de referência. Análise de regressão logística multivariada multinomial foi conduzida para avaliar a influência de fatores relacionados aos participantes nas taxas de omissão e intrusão. Resultados Os resultados apontaram adequada sensibilidade (67,7%) e especificidade expressiva (95,2%). As taxas de omissão e de intrusão foram baixas, 22,8% e 29,5%, respectivamente, quando considerados todos os itens alimentares. O item pizza/hambúrguer exibiu a maior taxa de omissão, enquanto os laticínios apresentaram a maior taxa de intrusão. Escolares que frequentavam a escola no turno vespertino apresentaram maior probabilidade de intrusões de itens alimentares comparados aos escolares do turno matutino. Conclusão O Questionário Alimentar do Dia Anterior Online apresentou validade satisfatória para a análise do consumo alimentar em nível de grupo de escolares do segundo ao quinto ano de escola pública.

Diagnostic accuracy of anthropometric indicators to predict excess body fat in adolescents aged 11-14 years / Acurácia de indicadores antropométricos de obesidade para predição do excesso de gordura corporal em adolescentes de onze a catorze anos

Abstract The aim of this study was to evaluate the diagnostic accuracy of body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR) and conicity index (C index) for the prediction of excess body fat (estimated by skinfold thickness) and determine the cutoffs of anthropometric indicators (BMI, WC, WHtR and C index) that best predict excess body fat. Overall, 1,589 students (11-14 years old) from public and private schools of Florianopolis (southern Brazil) participated in this study. Anthropometric measurements of body weight, height, WC, and skinfolds (triceps and medial calf) were collected. ROC curves were used to compare the discriminatory power of BMI, WC, WHtR and C index in detecting adolescents with excess body fat (relative body fat estimated with skinfold thickness). All anthropometric indicators, except for C index in females, obtained good performance in the detection of excess body fat in both sexes, expressed as the area under the ROC curve. Cutoffs for boys and girls, respectively, associated with high excess body fat were BMI (20.7 and 19.7kg/m2), WC (68.7 and 65.9cm), WHtR (0.43 and 0.41cm), and C index (1.13 and 1.11). The study showed that, except for C index in females, BMI, WC and WHtR can be used to identify excess body fat in adolescents, considering the suggested cutoffs from this research.

Resumo O objetivo deste estudo foi verificar a acurácia diagnóstica do índice de massa corporal (IMC), perímetro da cintura (PerC), razão cintura estatura (RCEst) e índice de conicidade (ÍndiceC) para detectar excesso de gordura corporal (estimada por meio de dobras cutâneas) e determinar os pontos de corte dos indicadores antropométricos (IMC, PerC, RCEst e ÍndiceC) que melhor predizem o excesso de gordura corporal. Participaram do estudo 1.589 escolares (11-14 anos) da rede de ensino pública e privada de Florianópolis, SC. Foram coletadas massa corporal, estatura, PerC e dobras cutâneas (tríceps e panturrilha medial). As curvas ROC foram utilizadas para comparar o poder discriminatório do IMC, PerC, RCEst e ÍndiceC na identificação de adolescentes com excesso de gordura corporal. Todos os indicadores antropométricos, exceto o ÍndiceC para as moças, obtiveram bom desempenho na detecção do excesso de gordura corporal em ambos os sexos. Os pontos de corte para rapazes e moças, respectivamente, associados com a gordura corporal elevada foram IMC de 20,7 e 19,7kg/m2, PerC de 68,7 e 65,9cm, RCEst de 0,43 e 0,41cm e ÍndiceC de 1,13 e 1,11. Todos os indicadores antropométricos, exceto o ÍndiceC para o sexo feminino, podem ser empregados em adolescentes, a partir dos pontos de corte sugeridos nessa pesquisa, na detecção de excesso de gordura corporal.

Diagnostic accuracy of anthropometric indices in predicting excess body fat among seven to ten-year-old children / Acurácia diagnóstica de índices antropométricos na predição do excesso de gordura corporal em crianças de sete a dez anos

PURPOSE: To evaluate the accuracy of the body mass index (BMI), waist circumference (WC) and waist-to-height ratio (WHtR) in detecting excess body fat among schoolchildren in Florianópolis, Santa Catarina. METHODS: Cross-sectional study with 2,772 schoolchildren aged seven to ten years. Receiver Operating Characteristic (ROC) curves were used to compare the diagnostic accuracy of the BMI, the WC and the WHtR in identifying children with excess body fat (defined as values that were equal to or higher than the 90th percentile of the standardized residuals obtained from the sum of the four skinfolds thickness). Likelihood ratio estimates were used to select, for each anthropometric index, the cut-off points that presented the highest association with excess body fat. RESULTS: The BMI, WC and WHtR performed well in detecting excess body fat, indicated by areas under the ROC curve (AUC) close to 1.0, with slightly higher AUC for the BMI in comparison to the WC and the WHtR concerning both sexes. Highly sensitive and specific cut-off points were derived for the three anthropometric indices. Sensitivity ranged from 85.7 to 92.9% for the BMI, from 78.6 to 89.7% for the WC, and from 78.6 to 89.2% for the WHtR. Specificity ranged from 83.2 to 91.4%, from 75.0 to 90.7%, and from 77.4 to 88.3% for the BMI, the WC and the WHtR, respectively. CONCLUSION: BMI, WC and WHtR can be used as diagnostic tests to identify excess body fat in children from seven to ten years of age. .

OBJETIVO: Avaliar a acurácia do índice de massa corporal (IMC), circunferência da cintura (CC) e razão cintura-estatura (RCEst) no diagnóstico do excesso de gordura corporal em escolares de Florianópolis, Santa Catarina. MÉTODOS: Estudo transversal com 2.772 escolares de sete a dez anos. Curvas ROC (Receiver Operating Characteristic) foram utilizadas para comparar a acurácia diagnóstica do IMC, CC e RCEst na identificação de crianças com excesso de gordura corporal (definido como valores iguais ou superiores ao percentil 90 do resíduo padronizado do somatório de quatro dobras cutâneas). A estimativa da razão de verossimilhança foi utilizada para selecionar, em cada índice antropométrico, o ponto de corte de maior associação com o excesso de gordura corporal. RESULTADOS: O IMC, a CC e a RCEst obtiveram bom desempenho na detecção do excesso de gordura corporal, indicado por áreas sob a curva (ASC) ROC próximas a 1,0, com uma ASC um pouco maior para o IMC do que para a CC e RCEst em ambos os sexos. Para os três índices antropométricos, pontos de corte altamente sensíveis e específicos foram derivados. A sensibilidade variou de 85,7 a 92,9% para o IMC, de 78,6 a 89,7% para a CC e de 78,6 a 89,2% para a RCEst. A especificidade variou de 83,2 a 91,4%, de 75,0 a 90,7% e de 77,4 a 88,3% para o IMC, CC e RCEst, respectivamente. CONCLUSÃO: O IMC, a CC e a RCEst podem ser usados como teste diagnóstico para identificar o excesso de gordura corporal em crianças de sete a dez anos. .

Performance of references based on body mass index for detecting excess body fatness in schoolchildren aged 7 to10 years / Desempenho de referências baseadas no índice de massa corporal para a detecção do excesso de gordura corporal em escolares de 7 a 10 anos de idade

Objective: To compare the sensitivity and specificity of body mass index (BMI)-based classification systems and to determine the optimal cut-offs for predicting excess body fatness in schoolchildren. Methods: 2795 schoolchildren aged 7 - 10 years were examined. Excess body fatness was defined as the standardized residuals of the sum of three skinfold thickness ranking at or above the 90th percentile. The international BMI-based system recommended by the World Health Organization (WHO-2007) was evaluated on the basis of its sensitivity and specificity for detecting excess body fatness and compared with a national BMI reference (Brazil-2006). Likelihood ratios analysis was used to select the optimal cut-offs in each curve. Results: The two classification systems presented high sensitivity (92.5 - 98.6%) and moderate specificity (75.9 - 85.0%) for both sexes. The optimal BMI cut-offs improved specificity with no marked loss of sensitivity. Using the proposed BMI cut-offs, the post-test probability of predicting excess body fatness for children classified as non-overweight decreased from 10 (pre-test probability) to 1.4% in girls and to 1.1% in boys. For overweight children, this probability increased to more than 46.0%. Conclusion: The results showed that both the WHO-2007 and Brazil-2006 classification systems can be used as screening instruments for excess body fatness, and that one of the limitations of using the BMI-for-age references could be improved by refining the existing cut-offs. .

Objetivo: Comparar a sensibilidade e especificidade de sistemas de classificação baseados no índice de massa corporal (IMC) e determinar os melhores pontos de corte na predição do excesso de gordura corporal em escolares. Métodos: 2795 escolares com idade entre 7 a 10 anos foram examinados. O excesso de gordura corporal foi definido como os resíduos padronizados do somatório de três dobras cutâneas iguais ou superiores ao percentil 90. O sistema internacional baseado no IMC, recomendado pela Organização Mundial de Saúde (OMS-2007), foi avaliado com base em sua sensibilidade e especificidade para detecção do excesso de gordura corporal e comparado com uma referência do IMC nacional (Brasil-2006). A análise da razão de verossimilhança foi usada para selecionar os melhores pontos de corte em cada curva. Resultados: Os dois sistemas de classificação apresentaram alta sensibilidade (92,5 - 98,6%) e moderada especificidade (75,9 - 85,0%) para ambos os sexos. Os ótimos pontos de corte melhoraram a especificidade sem perda acentuada da sensibilidade. Usando os pontos de corte propostos, a probabilidade pós-teste de predizer o excesso de gordura corporal para crianças classificadas sem excesso de peso diminuiu de 10% (probabilidade pré-teste) para 1,4% em meninas e para 1,1% em meninos. Para crianças classificadas com excesso de peso, essa probabilidade aumentou para mais de 46,0%, em ambos os sexos. Conclusão: Os resultados mostraram que ambos os sistemas de classificação, OMS-2007 e Brasil-2006, podem ser usados como instrumentos de rastreio do excesso de gordura corporal. As limitações do uso de referências do IMC-para-idade podem ser melhoradas pelo refinamento dos pontos de corte existentes. .

Agregacao de fatores de risco para doencas e agravos cronicos nao transmissiveis em adultos de Florianopolis, SC / Clustering of risk factors for non communicable diseases in adults from Florianopolis, SC

Objetivo: Investigar o padrão de combinações de comportamentos de risco para doenças crônicas não transmissíveis e identificar os fatores sociodemográficos associados às combinações que excedem a prevalência esperada. Métodos: Inquérito com 1.996 adultos, residentes em domicílios servidos por linhas telefônicas fixas, no ano de 2005, em Florianópolis, SC. Os comportamentos investigados foram o tabagismo, consumo de álcool, inatividade física no lazer e consumo irregular de frutas. O padrão de simultaneidade dos comportamentos de risco foi avaliado pela razão entre a prevalência esperada e observada de cada uma das 16 possibilidades de combinação. O conjunto de comportamentos que excedeu a prevalência esperada constituiu o principal desfecho investigado. A regressão logística binomial e multinomial foi utilizada para avaliar a associação dos padrões de combinação e simultaneidade com variáveis sociodemográficas. Resultados: 43% dos homens e 36,6% das mulheres acumularam dois ou mais fatores de risco. Três (19,2%; IC 95% 16,7 - 21,7) e cinco (9,8%; IC 95% 8,0 - 11,6) combinações de comportamento excederam a prevalência esperada, respectivamente, entre os homens e as mulheres. Mulheres menos escolarizadas e de idade mais avançada apresentaram maior chance de agregação dos comportamentos de risco. Conclusão: Apesar de os homens apresentarem prevalências mais elevadas tanto dos comportamentos de risco isoladamente quanto das combinações dos mesmos, as mulheres apresentaram maior número de padrões que tenderam a se agregar além do esperado. O conhecimento sobre o padrão de combinação ...

Objective: To investigate clustering patterns of health risk behaviors for non communicable diseases and its associated factors. Methods: a Random telephone survey with 1,996 adults from Florianopolis, SC, was conducted in 2005. Tobacco use, high alcoholic intake episodes, fruit consumption and physical inactivity were investigated. Clustering was examined by the ratio between observed and expected prevalence of each of the 16 possible combinations. These clustered risk factors comprised the main outcome and binomial and multinomial logistic regression was conducted to examine socio-demographic correlates. Results: 43% of men and 36.6% of women clustered at least two health risk factors. Three (19.2%; CI 95% 16.7 - 21.7) and five (9.8%; CI 95% 8.0 - 11.6) specific combinations exceed the expected prevalence, respectively, in men and women. Women with low schooling level and older were more likely to cluster health risk behaviors. Conclusion: although men showed higher prevalence of single health risk behavior and its combinations, women presented more specific combinations that clustered above the expected. Knowledge on the clustering pattern of these health risk behaviors may guide the design of more effective health promotion initiatives. .

Sensitivity and specificity of body mass index-based classification systems for overweight in children 7-10 years old / Sensibilidade e especificidade dos sistemas de classificação para sobrepeso baseados no índice de massa corporal em crianças de 7-10 anos de idade

The objective of this study was to compare the sensitivity and specificity of BMI-based classification systems for detecting excess body fat in schoolchildren. A total of 2,795 schoolchildren aged 7 to 10 years were examined. Excess body fat was defined as the standardized residuals of sum of three skinfolds thickness ranking at or above the 90th percentile. The international BMI-based systems recommended by the International Obesity Task Force (IOTF) and the World Health Organization (WHO-2007) were evaluated on the basis of their sensitivity and specificity for detecting excess body fat and compared with a national BMI reference (Brazil-2006). The positive (LR+) and negative (LR-) likelihood ratios analysis was also used to compare the diagnostic accuracies of the three BMI criteria. The three classification systems presented moderately high sensitivity (78.4-98.6%) and specificity (75.9-91.6%) for both genders. Overall, the three classification systems showed both LR+ and LR- values consistent with a diagnosis of moderate evidence for overweight (LR+ above five and LR- below 0.2). The results showed that the three BMI classification systems can be used as screening instruments of excess body fat. However, the performance of the Brazil-2006 classification system was superior because it showed the best balance between the diagnostic accuracy indices.

O objetivo deste estudo foi comparar a sensibilidade e especificidade de sistemas de classificação baseados no índice de massa corporal (IMC) na detecção do excesso de gordura corporal em escolares. Um total de 2795 escolares com idade entre sete a dez anos foram examinados. O excesso de gordura corporal foi definido como os resíduos padronizados do somatório de três dobras cutâneas iguais ou superiores ao percentil 90. Os sistemas internacionais baseados no IMC recomendados pela International Obesity Task Force (IOTF) e Organização Mundial de Saúde (OMS-2007) foram avaliados com base em sua sensibilidade e especificidade para detecção do excesso de gordura corporal e comparado com uma referência do IMC nacional (Brasil-2006). Análise das razões de verossimilhança positiva (RV+) e negativa (RV-) também foi utilizada para comparar as precisões diagnósticas dos três critérios do IMC. Os três sistemas de classificação apresentaram sensibilidade (78,4-98,6%) e especificidade (75,9-91,6%) moderadamente alta para ambos os sexos. No geral, os três sistemas de classificação apresentaram valores de RV+ e RV-, condizentes com um diagnóstico de evidência moderada para o sobrepeso (RV+ acima de cinco e RV- abaixo de 0,2). Os resultados mostraram que os três sistemas de classificação do IMC podem ser usados como instrumentos de rastreio do excesso de gordura corporal. Entretanto, o desempenho do sistema de classificação Brasil-2006 foi superior porque mostrou o melhor equilíbrio entre os índices de acurácia diagnóstica.

Mudanças no consumo alimentar e atividade física de escolares de Florianópolis, SC, 2002 - 2007 / Changes in food consumption and physical activity in schoolchildren of Florianópolis, Southern Brazil, 2002 - 2007

OBJETIVO: Avaliar a mudança em cinco anos do consumo alimentar e nível de atividade física em escolares. MÉTODOS: Estudo com amostra representativa (n = 4.168) de escolares de sete a dez anos de idade de Florianópolis, SC. Medidas do consumo alimentar e atividade física foram realizadas em dois estudos de base escolar em 2002 (n = 2.936; 51% meninos; idade média = 8,5 anos) e 2007 (n = 1.232; 50,7% meninos; idade média = 8,6 anos), utilizando questionários ilustrados. O teste do qui-quadrado foi utilizado para avaliar a mudança no consumo de oito alimentos/grupos de alimentos, no atendimento às recomendações do Guia Alimentar para a População Brasileira e no nível de atividade física (avaliado segundo os terços de distribuição do escore e o tipo de deslocamento para a escola). As análises foram realizadas segundo a rede de ensino. RESULTADOS: Houve redução da proporção de crianças que relatou o consumo de frutas, verduras e legumes, feijão, carnes, guloseimas, pizza, batata frita e refrigerantes. Maior proporção de escolares da rede privada atendeu às recomendações de restrição de consumo de refrigerantes, pizzas e batata frita, e de maior consumo de frutas, verduras e legumes, em ambos os estudos. Por outro lado, maior proporção de escolares da rede pública atendeu às recomendações para o consumo de carnes em 2007. Os valores medianos do escore de atividade física diminuíram em 2007. Em ambos os anos escolares da rede privada foram mais ativos. A proporção de escolares que se deslocou ativamente para a escola reduziu de 49% para 41% (p < 0,01). CONCLUSÕES: Houve redução no consumo de alimentos marcadores de dieta saudável (feijão, carnes/peixes, frutas, legumes e verduras) e de alimentos de alta densidade energética e baixo valor nutricional (refrigerantes, guloseimas e pizza/batatas fritas). Também houve decréscimo da proporção de escolares que relataram deslocamento ativo para a escola.

OBJECTIVE: To assess changes in food consumption and physical activity levels in schoolchildren. METHODS: A study was conducted with a representative sample (n = 4,168) of schoolchildren aged between seven and ten years living in the city of Florianópolis, Southern Brazil. Food consumption and physical activity were assessed in two school-based studies in 2002 (n = 2,936; 51% boys; mean age = 8.5 years) and 2007 (n = 1,232; 50.7% boys; mean age = 8.6 years), using illustrated questionnaires. The chi-square test was used to assess changes in the consumption of eight foods/food groups, in terms of the recommendations of the Brazilian Food Guidelines and physical activity levels (assessed according to tertiles of distribution of score and type of transportation to school). Analyses were performed according to the type of school attended (private or public). RESULTS: There was a reduction in the proportion of schoolchildren who reported eating fruits, vegetables, beans, meat, snack foods, pizza, French fries and sodas. A higher proportion of private school children met the recommendations that restricted the consumption of sodas, pizza and French fries and promoted the consumption of fruits and vegetables, in both studies. On the other hand, a higher proportion of public school children met the recommendations of meat consumption in 2007. Median values of scores of physical activity decreased in 2007. In both years, private school children were more active. The proportion of schoolchildren who actively commuted to school decreased from 49% to 41% (p < 0.01). CONCLUSIONS: There was a reduction in the consumption of markers of a healthy diet (beans, meat/fish, fruits and vegetables) and high-energy and low-nutrient foods (sodas, snack foods and pizza/French fries). In addition, there was a decrease in the proportion of schoolchildren who reported actively commuting to school.