Determinants of overweight in children under 4 years of age.

Objectives: To describe the prevalence of and factors associated with overweight in children under 4 years of age in Feira de Santana, state of Bahia, Brazil.

Methods: Cross-sectional study nested within a birth cohort of 793 children born in Feira de Santana, Brazil. Independent variables were related to infant characteristics, social and demographic factors, maternal reproductive aspects, and diet of the child at age 4 months. The dependent variable was nutritional status, as assessed by weight-for-height ratio compared to Multicentre Growth Reference Study standards and obtained with the use of the software ANTHRO. Z-scores of -2 and +2 above or below the median for the reference population were established as normality cutoff points. Child height and weight were measured with an anthropometer and digital scales, respectively; all measurements were taken in triplicate. The study was approved by the Research Ethics Committee of the Universidade Estadual de Feira de Santana (CEP/UEFS), under registration number 096/2006.

Results: The prevalence of overweight was 12.5%. Adequate birth weight (RR 2.75; 95%CI 1.50-5.05), primiparity (RR 1.61; 95%CI 1.09-2.35), and maternal employment outside the home at age 4 months (RR 1.73; 95%CI 1.16-2.59) were associated with overweight.

Conclusions: In this study, adequate birth weight, primiparity and maternal employment outside the home were associated with overweight in children. The rate of overweight found, which surpassed that reported by other studies conducted across the country (including Bahia), point to a risk of child obesity in Feira de Santana.