Obesity rates among children and adolescents have increased ten-fold over the last four decades

By Sally Robertson, B.Sc.Oct 11 2017

The number of children and adolescents (aged 5 to 19 years) across the world who classify as obese has increased ten-fold over the last forty years, according to an analysis led by Imperial College London and the World Health Organization (WHO).

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As reported in The Lancet, the proportion of people in this age group classifying as obese rose from less than 1% (around 5 million girls and 6 million boys) in 1975 to almost 6% (50 million) among girls and almost 8% (74 million) among boys in 2016. Overall, the number of obese children and adolescents rose from 11 million in 1975 to 124 million in 2016, a more than ten-fold increase. In 2016, a further 213 million were overweight, but did not classify as obese.

The study, which has been published ahead of World Obesity Day (11th October), assessed body mass index (BMI) measurements available for almost 31.5 million people aged between 5 and 19 years and 97.4 million aged 20 years and older. This is the largest number of people ever to be assessed in an epidemiological study and the analysis involved more than 1,000 researchers.

According to lead author Majid Ezzati (Imperial College London), the increased obesity rates among children and adolescents continue to soar in low- and middle-income countries. The rates have plateaued more recently in high-income countries, although they remain unacceptably high.

"These worrying trends reflect the impact of food marketing and policies across the globe, with healthy nutritious foods too expensive for poor families and communities,” says Ezzati. “The trend predicts a generation of children and adolescents growing up obese and also malnourished.”

Fiona Bull, from WHO, says the data highlight and reinforce that obesity and overweight is a global health crisis that threatens to become worse in years to come unless drastic action is taken. WHO will be publishing a summary of the Ending Childhood Obesity (ECHO) Implementation Plan, which provides guidance on ways to curb the problem. The organization has also released guidance calling on healthcare workers to identify and manage children who are overweight and obese.

"Countries should aim particularly to reduce consumption of cheap, ultra-processed, calorie dense, nutrient poor foods,” recommends Bull. She also advises that the time children spend on screen-based and sedentary leisure activities should be reduced and more physical activity encouraged.

According to Sophie Hawkesworth from the Wellcome Trust, the trust is working together with global health partners and the international research community to identify research opportunities that could improve understanding of malnutrition and the associated long-term consequences.