Screen-viewing time has been associated with adverse health outcomes. Data on the predictors of youth screen-viewing time is predominately from older children in North America. Parental and home media environment factors that are associated with screen-viewing time could be targeted in interventions. Examine if parental screen-viewing time and electronic media (access to game equipment, TVs, PCs, and laptops) environment factors were associated with Portuguese children's screen-viewing time and if associations differed by child age (1 hour using combined other media on weekdays and weekend days. Parental TV-viewing time was associated with Portuguese children's TV-viewing time. The numbers of TVs in the household and electronic games equipment access were also associated with TV- and combined other media-viewing/usage time.

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.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. Am. J. Hum. Biol. 25:733–742, 2013.

Summary: Background: Maternal smoking during pregnancy has been associated with increased risk of childhood overweight/obesity defined by body mass index (BMI). We examined its association with a range of adiposity measures and cardiovascular indicators in children aged 3–10 years.Methods: We used data from a cross‐sectional study of schoolchildren across mainland Portuguese districts (2009–2010). We applied quantile regressions to examine maternal smoking associations with adiposity (n = 17 286), blood pressure (BP) and resting pulse rate (RPR) (n ≈ 2500) measures across the age range, adjusting for prenatal and early life factors.Results: Maternal smoking during pregnancy was associated with increases in offspring adiposity levels. The difference in median BMI between children of smokers and non‐smokers was 0.39 kg m⁻² (95% confidence interval: 0.25, 0.53) in boys and 0.46 kg m⁻² (0.31, 0.62) in girls; 0.55 cm (0.24, 0.87) and 0.82 cm (0.45, 1.19), respectively, in median waist circumference; and 0.94 mm (0.49, 1.40) and 1.47 mm (0.87, 2.07) in median sum of (triceps, subscapular, suprailiac) skin‐folds. The associations appeared to be stronger with increasing age. The differences in the 90th centile tended to be greater than those in median. There was no consistent association of maternal smoking with BP and RPR.Conclusions: Children whose mother smoked during pregnancy had higher adiposity levels than children of non‐smokers, across several measures, particularly among older children. Although there was no consistent association with cardiovascular indicators, maternal smoking association with childhood obesity may have implications for cardiovascular risk factors over the life course.