It is a cross-sectional and multicenter study to examine two hundred children aged between 1-3 years, duly enrolled under full-time regimen in public schools of the cities of Santo André (SP), Uberaba (MG), Porto Alegre (RS) and Natal (RN). The Principal Site of study will be Fundação de Medicina do ABC, located in the city of Santo André, while Universidade Federal do Triângulo Mineiro, Universidade Federal of Ciências da Saúde de Porto Alegre and Universidade Federal do Rio Grande do Norte will be the other Sites. For such purpose, fifty children from each Early Childhood Public School will be screened according to the inclusion criteria and invited to participate in the study. Each State may include more than one Institution, if required to reach the total number of children established previously.