More Children Will Be Obese Than Underweight by 2022

A new pooled analysis of more than 2,400 population-based measurement studies of nearly 130 million people suggests that if current trends continue, more children and adolescents will be obese than underweight by 2022.

Mean body-mass index (BMI) and obesity in children and adolescents aged 5-19 has increased tenfold in most countries in the past 40 years, according to the joint study from Imperial College London and the World Health Organization (WHO). While BMI has recently plateaued in most high-income countries, albeit at high levels, it continues to accelerate in parts of Asia.

Despite this, there are still more underweight (192 million) than overweight (124 million) children and adolescents worldwide. Underweight children are increasingly concentrated in south Asia and central, east and west Africa.

The projections paint a disconcerting picture for hospital systems, who will bear the brunt of the increased health burdens that come with growing obesity rates, according to Dr Juana Willumsen (pictured), WHO technical officer, nutritionist and expert on obesity.

“The rising costs of treating obesity and overweight co-morbidities, such as diabetes, cardiovascular diseases and procedures like hip and knee replacements, places great pressure on health systems,” Willumsen said in an interview with MD Magazine. “This will require some changes and adaptations to current practices.”

Willumsen recommended that health systems work towards detecting and addressing malnutrition in all its forms, from screening for both underweight and overweight in young children, to providing the kind of counselling and care needed for people who are overweight and obese. They should also account for the psychosocial consequences felt by many people living with obesity too, including younger people, who face stigmatization at school because of their weight, she said.

In high-income countries, many health facilities are equipped to help respond to the rising number of people needing support for obesity and overweight. But in many low- and middle-income countries, such capacities are often lacking, whether through lack of investment, political will to confront such issues, or a combination of both.

“Worryingly, it is such countries that are feeling the brunt of the steepest increase in rates of obesity and overweight, especially in younger people, which means more people will live with obesity, and their accompanying health consequences," Willumsen said. "This, in turn, puts more strains on often already strapped health systems.”

The worrying trend in worldwide obesity and BMI rates reflects the impact of aggressive food marketing policies across the globe, according to the study’s lead author, Professor Majid Ezzati (pictured), of Imperial College London’s School of Public Health.

“Healthy, nutritious foods [are] too expensive for poor families and communities,” Ezzati said. “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.”

From 1975 to 2016, children’s and adolescents’ age-standardized mean BMI increased globally by 0.32 kg/m² per decade for girls and 0.40 kg/m² per decade for boys, leading to virtually identical age-standardized mean BMIs of 18.6 kg/m² for girls and 18.5 kg/m² for boys in 2016.

In 1975, the global age-standardized mean BMI of children and adolescents aged 5-19 was 17.2 kg/m² for girls and 16.8 kg/m² for boys. Mean BMI was lowest in south Asia, followed by east Africa. In 2016, the lowest mean child and adolescent BMIs were still those in south Asia and east Africa, with age-standardized mean BMIs between 16.9 and 17.9 kg/m² for girls and boys.

Girls in Melanesia, Polynesia and Micronesia, and the high-income English-speaking region had the highest age-standardized mean BMI in 1975, all above 19kg/m². The highest mean BMIs for boys were those in Polynesia and Micronesia, (19.1 kg/m²) followed by the high-income English-speaking region.

In 2016, the highest BMIs were those in Polynesia and Micronesia for both sexes, followed by Melanesia and the high-income English-speaking region. Age-standardized mean BMIs of girls and boys in Polynesia and Micronesia, which were 23.1 kg/m² and 22.4 kg/m², respectively, were higher than those of adults in some regions. Children’s and adolescents’ age-standardized mean BMI was also more than 20 kg/m² in Melanesia and many parts of Latin America and the Caribbean.

The regional rankings in 2016 differed slightly between children aged 5-9 years and adolescents aged 10-19 years. For example, the lowest mean BMI in children aged 5-9 years was seen in east Africa in both sexes, whereas in those aged 10-19 years, south Asian girls and boys had lower mean BMI than their African peers.

“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,” said Fiona Bull, MBE, PhD, Msc. (pictured), program coordinator for surveillance and population-based prevention of noncommunicable diseases at WHO.