Overweight prevalence increases from 2 to 8 years of age among children with immigrant background in a Norwegian multiethnic population.

Aims: Little is known about ethnic disparities in childhood obesity in Europe. We explored the development of ethnic differences in overweight (including obesity) from age 2 to 8 years.

Methods: We collected routine weight and height measures for 604 children from the Norwegian multiethnic, population-based STORK Groruddalen pregnancy and birth cohort (52.6% European, 26.8% south Asian, and 20.5% Middle East/north African ethnic background). Using chi-square tests for trend and binominal logistic regression analyses adjusted for sex and maternal factors, we explored the development of ethnic differences in overweight. For children with south Asian origin, we performed body mass index adjustments considering their relatively higher adiposity.

Results: From age 2 to 8 years, prevalence of overweight was stable in European children (13.1% at 2 years, and 15.1% at 8 years). In children with immigrant background, prevalence increased; from 5.4% to 17.2% in children with south Asian origin, and from 16.2% to 35.8% in children with Middle East/north African background (p for trend < 0.001 in both groups). At age 8 years, the latter group had almost a threefold higher risk of overweight (odds ratio (OR) 2.89; 95% confidence interval 1.54-5.42) compared with European-origin children, while ethnic south Asian children had a double risk (OR 2.07; 1.19-3.59) after adjustments for body composition.

Conclusions: From 2 to 8 years of age, prevalence of childhood overweight increased in children with immigrant background but remained stable in ethnic Europeans. To reduce ethnic disparities in health, effective efforts to prevent obesity in children with immigrant background should start very early in life.