These researchers pooled data from 2,426 population-based studies presenting height and weight measurements of 128.9 million children aged ≥5 years, including 31.5 million aged 5–19 years. Bayesian analysis estimated trends in mean BMI among these children and adolescents from 1975 to 2016 in 200 countries, as well as prevalence of BMI from underweight to obesity: moderate and severe underweight was defined as >2 SD below the median of the WHO growth reference for children and adolescents; mild underweight was defined as 2 SD to >1 SD below the median; healthy weight was defined as 1 SD below the median to 1 SD above the median; overweight but not obese was defined as >1 SD to 2 SD above the median; obesity was defined as >2 SD above the median. From 1975 to 2016, mean BMI and obesity increased in children and adolescents in most countries. These rising trends have recently plateaued at high levels in many high-income countries, but have accelerated in parts of Asia.
