Child obesity is now more common than undernutrition – what do we do?

For the first time, more children worldwide are living with obesity than undernutrition. The shift indicates childhood malnutrition has entered a new phase, one that the world is ill-equipped to address. While there are proven strategies for reducing hunger, few exist for tackling obesity.

“Despite years of efforts to really prevent obesity, particularly among children and youth, it is clear that we are not doing that great of a job,” says Andrea Richardson at RAND, a non-profit research organisation in California.

In a new report, Harriet Torlesse at UNICEF in Belgium and her colleagues analysed the nutritional status of children between 5 and 19 years old using data from the Non-communicable Disease Risk Factor Collaboration. This collaborative database spans more than 160 countries and territories, representing more than 90 per cent of children worldwide.

The report revealed that, since 2000, global childhood obesity rates have roughly tripled. About 9.4 per cent of children today live with obesity, compared with 9.2 per cent who are undernourished – the first time that obesity has surpassed undernutrition among children.

The shift is largely driven by rising obesity rates in low- and middle-income countries, where “more than 80 per cent of children living with overweight and obesity in the world are”, says Torlesse. “It is no longer a high-income problem. It is very much a problem globally.”

The implication is that governments and other organisations must rethink their approach to childhood malnutrition. “You’re not just looking at undernutrition, you’re looking at malnutrition in all its forms,” says Shibani Ghosh at Cornell University in New York state. The trouble is, we don’t have an effective playbook for combatting obesity like we do for hunger.

The UNICEF report blames rising childhood obesity rates on the spread of ultra-processed foods. These products, made with industrialised processes, contain additives and preservatives. They also tend to be high in fats, sugars and salt – think packaged cookies, candies, chips and sodas. According to the report, ultra-processed foods account for at least half of the calories consumed by children in Australia, Canada, the US and the UK, and about a third of those consumed by children in some low- and middle-income countries, including Argentina and Mexico.

Numerous studies have associated ultra-processed foods with an increased risk of obesity. Yet policies designed to reduce consumption of them – many of which UNICEF recommends – rarely make a dent in obesity rates.

Consider taxes on unhealthy foods. In 2014, Mexico became the first country to tax certain high-calorie foods and sugar-sweetened beverages. Sales of these products subsequently fell, especially among lower-income households, but adolescent obesity rates barely budged. In fact, they dipped only in teenage girls, as was the case in the UK after implementing a tax on sugary beverages in 2018.

Meanwhile, Chile has some of the most sweeping regulations on ultra-processed foods. In 2016, it restricted the marketing of these foods and beverages and mandated that those high in calories, sodium, saturated fats and sugar have front-of-package warning labels to deter consumers. Obesity rates in children aged 4 to 6 subsequently fell 1 to 3 percentage points a year later – but returned to the baseline in 2018. In fact, by 2019, obesity rates had risen by 2 percentage points in those who were 14 years old, underscoring how little effect these policies had.

But Torlesse sees it differently. “There is no single intervention that will do good,” she says. “So you see some countries doing a soda tax, or some countries putting on food labels. That is all admirable, but unless you tackle it from all sides, we’re not going to have the shift we need.”

That is why the report also encourages policies that increase the availability and affordability of nutritious foods, such as subsidies or school lunch programmes. It stresses the importance of nutrition education and alleviating poverty as well. “The same reasons why we see people suffering with undernutrition are very much the same reasons why we see people suffering with overnutrition,” says Richardson. “It is really rooted in a lack of financial resources, living in impoverished areas, poor access to nutritious foods and safe drinking water.”

No country has implemented all of UNICEF’s recommendations, so it is still an open question whether they will be sufficient at reining in obesity. “The implicit assumption is that because there is increasing consumption of unhealthy foods, overweight and obesity rates are increasing,” says Ghosh. “And that could be one part of the explanation.”

But there are probably additional drivers, too, such as stress, pollution and even genetic changes.

“We really need to see this as a holistic major public health emergency,” says Richardson. “Our children are our future. They should all be healthy. If our children are not thriving, our future doesn’t look very bright.”