Tenfold increase in child obesity

Over the last 40 years, there has been a tenfold increase in childhood and adolescent obesity, according to a new
study by Imperial College London and the World Health Organisation. By 2022, there will be more obese children and adolescents alive than those underweight. The news comes as we mark World Obesity Day, 11th October.

The study, which is published in The Lancet,  analysed weight and height measurements from nearly 130 million people aged over five (31.5 million people aged 5 to 19, and 97.4 million aged 20 and older), the largest number of participants ever involved in an epidemiological study. More than 1000 researchers contributed to the study, which looked at body mass index (BMI) and how obesity has changed worldwide from 1975 to 2016.

During this period, obesity rates in the world’s children and adolescents increased from less than 1% (equivalent to five million girls and six million boys) in 1975 to nearly 6% in girls (50 million) and nearly 8% in boys (74 million) in 2016. Combined, the number of obese 5 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.”

Professor Ezzati adds: “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. The trend predicts a generation of children and adolescents growing up obese and also malnourished. 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.”

Children and adolescents have rapidly transitioned from mostly underweight to mostly overweight in many middle-income countries, including in East Asia, Latin America and the Caribbean. The authors say this could reflect an increase in the consumption of energy-dense foods, especially highly processed carbohydrates, which lead to weight gain and poor lifelong health outcomes.

Dr Fiona Bull, programme coordinator for surveillance and population-based prevention of noncommunicable diseases (NCDs) at WHO, said: “These data highlight, remind and reinforce that overweight and obesity is a global health crisis today, and threatens to worsen in coming years unless we start taking drastic action.”

Global data for obesity and underweight

In 2016, there were 50 million obese girls and 74 million obese boys in the world, while the global number of moderately or severely underweight girls and boys was 75 million and 117 million respectively.

The number of obese adults increased from 100 million in 1975 (69 million women, 31 million men) to 671 million in 2016 (390 million women, 281 million men). Another 1.3 billion adults were overweight, but fell below the threshold for obesity.

The largest increase in the number of obese children and adolescents was seen in East Asia, the high-income English-speaking region (USA, Canada, Australia, New Zealand, Ireland and the UK), and the Middle East and North Africa.

In 2016, obesity rates were highest overall in Polynesia and Micronesia, at 25.4% in girls and 22.4% in boys, followed by the high-income English-speaking region. Nauru had the highest prevalence of obesity for girls (33.4%), and Cook Islands had the highest for boys (33.3%).

In Europe, girls in Malta and boys in Greece had the highest obesity rates, at 11.3% and 16.7% of the population respectively. Girls and boys in Moldova had the lowest obesity rates, at 3.2% and 5% of the population respectively.

Girls in the UK had the 73rd highest obesity rate in the world (6th in Europe), and boys in the UK had the 84th highest obesity in the world (18th in Europe).

Among high-income countries, the USA had the highest obesity rates for girls and boys.

Underweight:

India had the highest prevalence of moderately and severely underweight under-19s throughout these four decades (24.4% of girls and 39.3% of boys were moderately or severely underweight in 1975, and 22.7% and 30.7% in 2016). 97 million of the world’s moderately or severely underweight children and adolescents lived in India in 2016.

Solutions exist to reduce child and adolescent obesity:

In conjunction with the release on the new obesity estimates, WHO is publishing a summary of the Ending Childhood Obesity (ECHO) Implementation Plan. The plan gives countries clear guidance on effective actions to curb childhood and adolescent obesity. WHO has also released guidelines calling on frontline healthcare workers to actively identify and manage children who are overweight or obese.