The number of obese children and adolescents (aged five to 19 years) worldwide has risen tenfold in the past four decades.
If current trends continue, more children and adolescents will be obese than moderately or severely underweight by 2022, according to a new study led by Imperial College London and WHO.
The study analysed weight and height measurements from nearly 130 million people aged over five years (31.5 million people aged five to 19, and 97.4 million aged 20 and older), making it the largest ever number of participants involved in an epidemiological study.
More than 1000 contributors participated in the study, which looked at body mass index (BMI) and how obesity has changed worldwide from 1975 to 2016.
Obesity rates in the world's children and adolescents increased from less than 1 per cent (equivalent to five million girls and six million boys) in 1975 to nearly 6 per cent in girls (50 million) and nearly 8 per cent in boys (74 million) in 2016.
Combined, the number of obese five to 19 year olds rose more than tenfold globally, from 11 million in 1975 to 124 million in 2016.
An additional 213 million were overweight in 2016 but fell below the threshold for obesity.
Lead author Professor Majid Ezzati of Imperial's School of Public Health, said, "Over the past four decades, obesity rates in children and adolescents have soared globally, and continue to do so in low- and middle-income countries.
More recently, they have plateaued in higher income countries, although obesity levels remain unacceptably high.
The trend predicts a generation of children and adolescents growing up obese and at greater risk of diseases, like diabetes.
We need ways to make healthy, nutritious food more available at home and school, especially in poor families and communities, and regulations and taxes to protect children from unhealthy foods.