Overweight Declines While Underweight Increases in Portuguese Children Aged 2-6 Years

Excess weight and thinness frequently coexist within the same family, a phenomenon called dual burden households. This is a growing public health concern. Obesity prevention efforts like family dietary caloric restriction may inadvertently affect underweight individuals, as some studies suggest, but this is not fully established. We previously showed a decreasing trend in childhood obesity in Portugal, but few studies have focused on preschool children and particularly, on the thinness changes throughout the last decades. Using data from three cross-sectional studies, this brief report examines trends in underweight, overweight and obesity among children from 2009 to 2024. It also explores how sociodemographic factors associate with excess weight in each study year.