UNICEF’s new report warns that junk food and weak regulation are driving a hidden epidemic that could cost trillions and derail decades of progress in child health. According to UNICEF’s new Child Nutrition Report, about 9.4 per cent of school-age kids (ages 5–19) are living with obesity, compared to 9.2 per cent who are underweight. Twenty-five years ago, the gap was much wider: Nearly 13 per cent of kids were underweight, while just 3 per cent had obesity. Over time, those lines have converged and flipped.
It might feel odd to put obesity in the same bucket as underweight; one has long been seen as a problem of scarcity, the other of excess. But public health experts now define both as forms of malnutrition, which they describe in three dimensions: not enough food, too much of the wrong food, and hidden hunger from micronutrient deficiencies.
Fewer kids are dangerously thin than two decades ago. That decline really matters because being underweight can mean stunted height, impaired brain development, weak immunity, and, in worst cases, a higher risk of death. So, the fact that those numbers are falling is genuine progress.
But it’s overshadowed by how quickly obesity has surged, with 188 million children now living with it, though where it shows up most varies widely by region. Obesity in children isn’t just about size; it raises risks for Type 2 diabetes, high blood pressure, cardiovascular disease, and even certain cancers later in life.
Starting so young makes the costs even higher. By 2035, being overweight and obesity are expected to drain more than $4 trillion a year globally, about 3 per cent of the world’s GDP. UNICEF bases its 2025 crossover on projections from survey data through 2022, and while the precise year carries some uncertainty, the trend is clear.
And it’s still pointing upward; the report projects child obesity rates will continue to climb through 2030, especially in Latin America, the Middle East, and East Asia. The shift aligns with the change in the kind of food environment today’s kids are raised in. Supermarkets, schools, and corner stores are stocked with foods high in calories, added sugar, saturated fat, and salt. Think sodas, packaged snacks, instant noodles — the kind of products that are designed to be cheap, convenient, and irresistible.
Ultra-processed foods — the buzzword taking health circles by storm — tend to encompass such foods. A rare randomised trial at the US National Institutes of Health found that people on ultra-processed diets ate about 500 extra calories per day than those on minimally processed ones.
Most other studies show associations between ultra-processed food intake and obesity or poor health, though they can’t prove cause and effect. The other shift in the last 25 years is that kids today are far less active than even a generation ago. In global survey reports, more than 80 per cent of adolescents fail to get the World Health Organisation-recommended hour of daily exercise, a sedentary shift that makes the impact of poor diets worse.
In some parts of the Pacific Islands, more than a third of children are obese, a trend linked to growing reliance on imported processed foods over traditional diets. In sub-Saharan Africa and South Asia, underweight is still more common. “Latin American countries are worried that obesity and its consequent chronic disease will bankrupt their health systems,” said Nestlé.
That concern has pushed governments to act faster than most. Chile’s 2016 warning label law and ad-ban package cut purchases of sugary drinks and snacks, and Mexico this year banned junk food in public schools, reshaping choices for 34 million children. “Impact studies show that they work to a considerable extent,” Nestlé added. The UK’s soft drinks tax points in the same direction, pushing companies to reformulate beverages with less sugar.
Of course, no single law is going to reverse the obesity curve, and nearly every country has struggled to get a handle on it. But measures like warning labels, soda taxes, and marketing restrictions at least sketch out what a serious policy toolkit could look like.
The decline in underweight is worth celebrating. But the rise of obesity, now surpassing it, reframes what malnutrition means in the 21st century. Calories alone are no longer the main problem; it’s the kind of calories children are consuming.
