Maternal breastfeeding, early introduction of non-breast milk, and excess weight in preschoolers / Aleitamento materno, introdução precoce de leite não materno e excesso de peso na idade pré-escolar

Abstract Objective: Investigate associations between excess weight in preschool children, breastfeeding duration and age of non-breast milk introduction. Methods: Cross-sectional study of a representative sample of 817 preschool children, aged 2-4 years, attending municipal day care centers in the city of Taubaté. The weight and height of children were measured in the day care centers in 2009, 2010 and 2011. The body mass index z-score (BMIz) was calculated and children were classified as risk of overweight (BMIz≥1 to<2) or excess weight (BMIz≥2). Data analysis was carried out by comparison of proportions, coefficient of correlation and multivariate linear regression. Results: The prevalence of risk of overweight was 18.9% and of excess weight (overweight or obesity) was 9.3%. The median duration of breastfeeding and age of introduction of non-breast milk was 6 months. The child's BMIz showed direct correlation with birth weight (r=0.154; p<0.001) and maternal body mass index (BMI) (r=0.113; p=0.002). The correlation was inverse with the total duration of breastfeeding (r=−0.099; p=0.006) and age at non-breast milk introduction (r=−0.112; p=0.002). There was no correlation between the child's BMIz with birth length, duration of exclusive breastfeeding and mother's age. Conclusions: The earlier the introduction of non-breast milk, the higher the correlation with excess weight at preschool age.

Resumo Objetivo: Investigar relações existentes entre excesso de peso em pré-escolares, duração do aleitamento materno e a idade de introdução de leite não materno. Métodos: Estudo transversal de amostra representativa de 817 pré-escolares, 2-4 anos de idade, de creches municipais de Taubaté. O peso e a altura das crianças foram mensurados nas creches em 2009, 2010 e 2011. Calculado o escore z de Índice de Massa Corporal (zIMC), as crianças foram classificadas como risco de sobrepeso (zIMC≥1 a<2) ou como excesso de peso (zIMC≥2). A análise dos dados foi feita por comparação de proporções, coeficiente de correlação e regressão linear multivariada. Resultados: A prevalência de risco de sobrepeso foi 18,9% e de excesso de peso (sobrepeso ou obesidade) de 9,3%. A mediana de duração do aleitamento materno e a idade de introdução do leite não materno foi de 6 meses. O zIMC da criança evidenciou correlação direta com o peso ao nascer (r=0,154; p<0,001) e com o Índice de Massa Corporal (IMC) materno (r=0,113; p=0,002). A correlação foi inversa com a duração total do aleitamento materno (r=−0,099; p=0,006) e a idade de introdução de leite não materno (r=−0,112; p=0,002). Não houve correlação entre o zIMC da criança com o comprimento ao nascer, duração do aleitamento exclusivo e idade da mãe. Conclusões: Quanto mais precoce a introdução de leite não materno, maior a correlação com excesso de peso na idade pré-escolar.

Maternal breastfeeding, early introduction of non-breast milk, and excess weight in preschoolers. / Aleitamento materno, introdução precoce de leite não materno e excesso de peso na idade pré­escolar.

OBJECTIVE: Investigate associations between excess weight in preschool children, breastfeeding duration and age of non-breast milk introduction. METHODS: Cross-sectional study of a representative sample of 817 preschool children, aged 2 to 4 years, attending municipal day care centers in the city of Taubaté. The weight and height of children were measured in the day care centers in 2009, 2010 and 2011. The body mass index z-score (BMIz) was calculated and children were classified as risk of overweight (BMIz≥1 to<2) or excess weight (BMIz≥2). Data analysis was carried out by comparison of proportions, coefficient of correlation and multivariate linear regression. RESULTS: The prevalence of risk of overweight was 18.9% and of excess weight (overweight or obesity) was 9.3%. The median duration of breastfeeding and age of introduction of non-breast milk was 6 months. The child's BMIz showed direct correlation with birth weight (r=0.154; p<0.001) and maternal Body Mass Index (BMI) (r=0.113; p=0.002). The correlation was inverse with the total duration of breastfeeding (r=-0.099; p=0.006) and age at non-breast milk introduction (r=-0.112; p=0.002). There was no correlation between the child's BMIz with birth length, duration of exclusive breastfeeding and mother's age. CONCLUSIONS: The earlier the introduction of non-breast milk, the higher the correlation with excess weight at preschool age.