The role of exclusive breastfeeding and sugar-sweetened beverage consumption on preschool children's weight gain.

BACKGROUND: Sugar-sweetened beverages (SSBs) and breastfeeding practices have been recognized as important factors linked to children's weight status. However, no other studies have simultaneously investigated the role of each factor on children's conditional weight gain (CWG). OBJECTIVE: To evaluate the role of exclusive breastfeeding (EB) and the SSBs consumption on CWG from birth to the survey date among Brazilian preschool children (24-59 months old). METHODS: A nationally represented cross-sectional survey with complex probability sampling (n = 2421) was conducted. The outcome variable - CWG - represents how much an individual has deviated from its expected weight gain, given his or her prior weight. The multivariate linear regression to analyse the effects of EB and the consumption of SSBs on CWG were adjusted for economic status and maternal variables. RESULTS: There was a significantly protective effect of EB duration during the first year of life on CWG from birth to the survey date (-0.02 [-0.03; 0.00 95% confidence interval]); however, the SSBs intake promoted an effect on the weight gain that was 2.5-fold higher (0.05 [0.02; 0.08 95% confidence interval]) than the EB. CONCLUSION: As hypothesized, the exposure variables acted in opposite directions, but the harmful effect of SSBs intake had greater magnitude than the beneficial effect of EB on children's CWG.

Accuracy of obesity diagnosis in Brazilian adolescents: comparison of Cole et al and Must et al criteria with DXA percentage of fat mass.

OBJECTIVES: to assess the accuracy of the two most used anthropometric criteria: Must and Cole to diagnose obesity in adolescence comparing with percentage of fat mass determined by DXA. METHODOLOGY: cross-sectional study with 418 adolescents (52.4% males) attending a private school in São Paulo/Brazil. Anthropometric measures of height and weight were taken and BMI was calculated. Analysis of body composition was performed using the DXA to detect percentage of fat mass. Using the method proposed by Ellis & Wong (ERM) two sex-specific linear regression models of fat percentage for age in years were fitted. The comparison between the methods was carried out through the analyses of specificity and sensitivity with two residual percentiles as cutoff points (ERM85th and ERM95th) as standards. A logistic model was fitted to estimate the probability curves of obesity classification. RESULTS: the comparison of the two classic criteria for the diagnosis of obesity with the ERM85th and ERM 95th, yields for females the same sensitivities of 0.50 and 0.20 for both criteria. For males sensitivities for ERM 85th were 0.61 (Must) and 0.49 (Cole); while for ERM95th the sensitivities were 0.81 (Must) and 0.64 (Cole). Therefore, there are high probabilities that those criteria diagnose adolescents as obese, when actually they are not. CONCLUSION: the Must and Cole criteria were similar and present flaws for the diagnosis of obesity. In clinical practice and field studies anthropometric criteria should be evaluated as to the diagnostic accuracy along with other clinical parameters and, when feasible, the analysis of fatness percentage. However, the anthropometric criteria evaluated are efficient in the identification of non-obese adolescent in the two cutoff points considered.

Plasma total homocysteine in Brazilian overweight and non-overweight adolescents: a case-control study.

OBJECTIVE: To test the hypothesis that overweight adolescents have higher plasma total homocysteine (tHcy) levels than non-overweight adolescents and to explore the association between plasma tHcy levels with folate, vitamin B12 and some risk factors for CVD in both groups. METHODS: A case-control study conductec with 239 adolescentes aged 15-19 years in the city of São Paulo, Brazil; 86 overweight and 153 non-overweight frequency matched by age, gender, pubertal and socioeconomic status. tHcy, folate, vitamin B12, lipid profile, glucose, insulin and insulin resistance were measured. RESULTS: No significant differences were found in tHcy, folate and vitamin B12 levels between overweight and non-overweight groups. The geometric means of tHcy were elevated in both groups (overweight: 11.8 micromol/L; non-overweight: 11.6 micromol/L) higher for boys than for girls (P < or = 0.001). Folate deficiency was identified in 68.6% of total studied population. Triacylglycerol, LDL cholesterol, insulin resistance were higher and HDL cholesterol was lower in overweight that non-overweight adolescents. In the multiple linear regression model, in overweight group, tHcy was independently associated with age (P = 0.041), sex (P = 0.004) and folate (P = 0.022) and in non-overweight group, with age (P = 0.049), sex (P < 0.001), folate (P = 0.018) and vitamin B12 (P = 0.030). CONCLUSIONS: Obesity was not a determinant factor of tHcy levels. Age, sex and folate were independent determinants of plasma tHcy levels. The high prevalence of folate deficiency may have been responsible for the elevated tHcy levels in these adolescents, increasing the risk for future development of CVD.

Hábitos alimentares de escolares (1ª e 2ª séries) durante a merenda escolar em escolas públicas de São Paulo, SP / Alimentary habits of students during meal break time of public schools of São Paulo city

Objetivo:estudar o hábito alimentar de crianças e seus determinantes durante a merenda escolar, visando conhecer e intervir positivamente na formação dos hábitos alimentares. Metodologia: em amostra de 630 escolares, observou-se o consumo alimentar no horário destinado à merenda escolar, classificando-o em saudável e não saudável. Utilizaram-se tabelas de contingência para a descrição das frequências das variáveis. Para o estudo de efeitos individuais de cada variável independente, com controle dos efeitos das demais incluídas no modelo, foi utilizado modelo de regressão logística com estimativas de razões de chances (odds ratio), entre os grupos de escolares com hábito alimentar saudável e não saudável.Resultados: observou-se a alta prevalência de 77,5 por cento (n=488) do hábito alimentar não saudável. Obesidade e sobrepeso, sexo masculino e ir à escola a pé, que se constituíram em variáveis com significância de 0,10 na an´lise bivariada, deixaram de s

Efeitos dos viéses de sobrevivência nas prevalências da desnutriçäo em crianças no segundo ano de vida - Brasil, PNSN, 1989 / Effects of survival bias on the prevalence of malnutrition among two-year old children

A análise do crescimento da criança, mensurado por indicadores antropométricos, constitui-se em instrumento importante para avaliaçäo da condiçäo nutricional e do grau de desenvolvimento de uma sociedade. Neste artigo, utiliza-se o indicador P/E, com ponto de corte em - 2 Z, para estimar a prevalência da desnutriçäo em uma populaçäo de crianças no segundo ano de vida. Os dados da Pesquisa Nacional de Saúde e Nutriçäo - PNSN-1989 - foram utilizados para análise da variabilidade da prevalência de acordo com o gênero, renda familiar per capita, regiäo domiciliar e faixa etária trimestral. Baseando-se em estimativas relacionadas às taxas de mortalidade de crianças no primeiro ano de vida, cujas mortes poderiam ser atribuídas à desnutriçäo, aplicou-se a metodologia proposta por Boerma (1992) para corrigir os viéses de sobrevivência. Observou-se que, na faixa de menor renda, as taxas de prevalência de desnutriçäo, no segundo ano de vida passam de 5,5 por cento para 12,9 por cento, correspondendo a aumento de 117.159 desnutridos. Na faixa de maior renda, a variaçäo é de 1,8 por cento para 2,5 por cento, aumento de 6.760 crianças. Já, em relaçäo às regiöes geográficas do Brasil, constatou-se que na regiäo Nordeste a variaçäo foi de 5,2 por cento para 11,7 por cento, correspondendo a um incremento de 82.612 desnutridos. Na regiÒo Sudeste, a variaçäo foi de 1,9 por cento para 3,4 por cento, correspondendo a um aumento de 17.755 crianças desnutridas no segundo ano de vida.