Descrição
Objectives: Childhood obesity is a public health concern in Portugal. Socio-demographic and behavioral
factors are highly associated with obesity but are not clearly understood. This article aims to update the prevalence
of overweight and obesity in Portuguese children and to explore the influence and risks of socio-demographic
factors and behavioral factors.factors and behavioral factors.
Methods: A cross-sectional study of Portuguese children aged 3–10 years from all 18 mainland districts took place
between March 2009 and January 2010. The sample was composed by 17,136 children, 3–10 years of age (8,455 boys;
8,681 girls). Height, weight, and other anthropometric measurements were obtained by trained technicians. Body mass
index (BMI) was calculated along with other anthropometric variables. Data analyses took place between April and
September 2012. The overweight/obesity classification was established by age-and sex-specific BMI cut-off points as
defined by the International obesity task force (IOTF). Parents completed questionnaires about socio-demographic and
behavioral characteristics of the family.
Results: Almost 28% of the Portuguese children were overweight or obese (19.7% overweight; 8.2% obese). Prevalence
was greater in girls than in boys. Logistic regression models found that the odds of childhood obesity were significantly
affected by biological, socio-demographic, and behavioral factors.
Conclusions: The protective factors against childhood overweight/obesity in this sample of Portuguese children are:
(i) being male; (ii) having been breastfeed; (iii) having been born from mothers who did not smoke during pregnancy;
(iv) engaging in little sedentary behaviors (TV, PC, and playing electronic games); (iv) performing at least 1 h of moderate
physical activity every day; and (v) having parents with higher educational levels who also have their BMI within
the healthy ranges. Contract grant sponsor: Fundação para a Ciência e Tecnologia; Contract
grant number: FCOMP-01–0124-FEDER-007483.
; Varela-Silva, Maria I. 
