Confronting childhood obesity in a changing food landscape

As childhood obesity rises worldwide, global health experts warn that children are growing up in food environments shaped by ultra-processed products, pervasive digital marketing, and weak regulation. This year’s World Health Assembly highlighted the urgent need for stronger prevention and policy action.

Marketing for ultra-processed foods and sugary drinks follow children across the world into digital spaces. Photo: cottonbro

Carlo Petrini, the Italian activist who founded the Slow Food movement to defend local food cultures and biodiversity, spent decades warning that industrially produced food was impoverishing diets and making people sick. His life's work was a relentless crusade for food that was “good, clean and fair”, challenging the growing power of the global food industry.

His death coincided with the 79th World Health Assembly in Geneva, where many of the concerns he spent decades raising—from poor diets to the growing health burden of ultra-processed foods—were central to global public health debates.

Among the clearest signs of that shift is the rise in childhood obesity, which health officials warn is leading to serious long-term consequences. “Obesity is a major public health crisis,” says Dr Katrin Engelhardt, a scientist in the World Health Organization (WHO) Department of Nutrition and Food Safety, from the sidelines of the Assembly. Childhood obesity, she says, is a major risk factor for type 2 diabetes, which is increasingly appearing earlier in life, “with significant implications for our health systems, for our societies, and for our economies”.

But the UN health agency’s concerns are no longer directed only at the proliferation of fast-food outlets or the poor quality of food in school canteens or supermarket aisles. Experts warn that the commercial food industry is also saturating children’s digital lives. Through social media, video games, influencers, and algorithmic advertising, ultra-processed foods and sugary drinks now shadow children across digital spaces that are often personalised and largely beyond the reach of parents and regulators.

“Marketing through digital platforms is getting more aggressive. It is becoming more addictive—the difference between entertainment and commercial marketing is very difficult for children to distinguish,” Engelhardt warns.

Obesogenic environment for kids

In 2024, 35.5 million children under five globally were overweight. Most were not in high-income countries: 73% lived in lower-middle- and upper-middle-income countries, with nearly half in Asia and more than a quarter in Africa.

The shift is even clearer among older children. UNICEF’s 2025 report, Feeding Profit: How Food Environments Are Failing Children, found that one in five children and adolescents aged five to 19 are overweight. Since 2000, their number has more than doubled, from 194 million to 391 million.

“This is really a historic change. For the first time in our history, obesity has overtaken underweight among school-age children and adolescents.”

"This is really a historic change," says Mauro Brero, UNICEF's senior nutrition adviser. "For the first time in our history, obesity has overtaken underweight among school-age children and adolescents." The trend holds across all regions except South Asia and sub-Saharan Africa, though even there, obesity is rising faster than anywhere else.

WHO and UNICEF largely attribute childhood obesity to food environments designed to push children and families toward unhealthy choices. People are increasingly surrounded by cheap, energy-dense, ultra-processed products high in fat, sugar, and salt, which compete with, and often displace, fresher alternatives. These are the same products pushed through television advertisements, colourful packaging, influencers, gaming platforms, and social media feeds.

Food products are marketed through television advertisements, influencers, gaming platforms, and social media feeds, largely beyond the reach of parents and regulators. Photo: Kampus Production

A recent analysis published in Nature showed that in many high-income countries, childhood obesity rates are stabilising or plateauing, but in low- and middle-income countries (LMICs) they are accelerating. "The fastest rise," Engelhardt says, "is in countries that have health systems with the least capacity to respond.”

For Brero, the shift undermines the idea that childhood obesity is mainly attributed to individual choices or parental failure. “What we are seeing is that these choices are often driven by the market.”

Digital marketing shapes food preferences

In UNICEF’s 2024 global U-Report poll, a digital survey platform used to gather the views of young people across 171 countries, 75% of respondents aged 13 to 24 said they had seen advertisements for sugary drinks, snacks, or fast food in the previous week, with social media being the leading source.

Digital marketing, Brero says, is especially powerful because it is cheap, personalised, and often hidden inside entertainment. “Through algorithms, we have shown that companies capture children’s data: what children’s preferences are, what their behavioural profiles are,” he explains. “They are then able to reach children with more targeted advertising.” Influencers blur the line further. “They show products in their videos, but they do not disclose that this is a video with a marketing purpose,” Brero says.

“Digital marketing to children is moving very fast. It is changing platforms. It is changing the way companies reach children. And we, as adults, are not aware of that.”

For the food industry, the difficulty of proving a direct line from one advertisement to childhood obesity is often used as a defence. WHO does not argue that a single advertisement makes a child obese. The concern is the chain of influence, as repeated exposure to marketing shapes what children like, what they ask their parents to buy, what families purchase, and, ultimately, what children eat.

Engelhardt says WHO’s 2023 guideline to protect children from food marketing was based on two systematic reviews, which “clearly showed changes in food preferences, and also in food purchase and intake behaviours”.

The data on diet point in the same direction. UNICEF found that among adolescents aged 15 to 19, 60% had consumed more than one sugary food or beverage the previous day, 32% had consumed a soft drink, and 25% had consumed more than one salty processed food. In Argentina, Belgium, Chile, and Mexico, ultra-processed foods and beverages account for at least a third of adolescents’ total energy intake. In Australia, Canada, the United States, and the United Kingdom, they account for at least half. At that level, they are beginning to function like staple foods.

Children’s screen time, a sedentary behaviour that is increasing worldwide, compounds the issue. For Dr Simón Barquera, president of the World Obesity Federation and one of the architects of Mexico’s soda tax and warning-label policies, the problematic aspects of children’s screen time are not limited to time spent sitting still. “When they have a lot of screen time, it is not only physical inactivity,” he says, “it is also exposure to these messages—so it is a double problem.”

Barquera says digital marketing is moving faster than public health experts can track it. At a meeting at Obesity Week in the United States, he recalls, a speaker asked how many people in the room knew Twitch. Nobody raised a hand. Yet the platform, the speaker said, had become an important channel for marketing to children.

“Digital marketing to children is moving very fast,” Barquera says. “It is changing platforms. It is changing the way companies reach children. And we, as adults, are not aware of that.”

Children’s screen time, a sedentary behaviour that is increasing worldwide, increases exposure to targeted advertising for sugary and unhealthy foods. Photo: cottonbro

Regulating this space is possible, experts say, but requires governments to act comprehensively. Digital marketing now accounts for more than 60% of global advertising spending, and food companies have learned to embed their messages across social media, gaming platforms, influencer content, podcasts, and e-commerce, with each channel requiring its own regulatory approach.

This year UNICEF published a model law on marketing that gives governments a practical framework, including a dedicated chapter on digital environments. The core recommendation is a complete ban on digital marketing of unhealthy foods to children, rather than narrow restrictions that create loopholes. Norway has banned the marketing of unhealthy foods and drinks to children, while the United Kingdom has introduced restrictions on television and paid online advertising for less healthy foods.

Policy changes in the Americas

While regulating digital marketing remains complex, experts point to countries such as Mexico, the Dominican Republic, and Chile as evidence that strong policy interventions can reshape food environments and influence what people consume.

In 2014, Mexico introduced a 10% tax on sugary drinks. Although lower than the 20% recommended by WHO, Barquera says the effect was immediate: consumption fell by almost seven litres per person per year, equal to more than 200,000 tonnes of sugar not consumed. “This was not related to behaviour change, or to convincing or educating people,” he notes. “It was just automatic after the tax.”

Mexico later introduced warning labels on products high in sugar, calories, sodium, or saturated fat, pushing companies to reformulate their products. “The industry did not want to have this punishment of the warning labels,” Barquera says. By 2025, Mexico had approved a national education law banning sugary drinks, junk food, and ultra-processed products from schools.

In the Dominican Republic, health officials are betting that one of the most effective tools against obesity and diabetes can be found in people’s kitchens. Through a programme called SALSA, people learn how to adapt traditional Dominican recipes by understanding their glycaemic impact, portion sizes, and ingredients. “We recognise that education is needed around how people eat,” says Dr Andelys Virginia de la Rosa Toribio, who heads the country’s non-communicable disease (NCD) programme at the Ministry of Health.

The initiative also trains health workers to bring nutrition counselling into primary care, part of a strategy that begins with pregnant women and children and follows patients across the life course. When patients understand “how to eat and what to eat”, de la Rosa Toribio says, improvements in hypertension and diabetes indicators can come quickly, even before they lose weight.

Chile shows what a broader regulatory package can do. According to a WHO brief, the proportion of children under five who are overweight fell from 9.9% in 2012 to 8.7% in 2024. Over the same period, Chile introduced one of the world’s most comprehensive food policy packages, including higher taxes on sugary drinks, front-of-pack warning labels, and restrictions on marketing to children. Studies found that purchases of sugary drinks fell by nearly a quarter, while children’s exposure to television advertising for regulated foods and drinks dropped by 73%.

The lesson, experts say, is that voluntary industry pledges are not enough.

Obesity overlaps with undernutrition

Crucially, childhood obesity does not look the same everywhere. In LMICs, it often overlaps with undernutrition and micronutrient deficiencies.

The Pacific Islands offer one of the starkest examples. Dr Reynold 'Ofanoa, chief executive officer for health in Tonga, describes a crisis driven by imported processed foods with longer shelf life and the collapse of traditional diets. "Pacific Island countries carry one of the world's heaviest obesity burdens across all age groups, including children, and both sexes," he says. Tonga has responded with taxes on unhealthy foods and sugary drinks, health-promoting school programmes, and free breakfasts for primary and middle-school students.

“School is really the perfect platform to target adolescents. There you have all that it takes to build obesity, and also to unbuild obesity.”

In sub-Saharan Africa, the picture is complicated further by what Professor Eugene Sobngwi of Cameroon’s Ministry of Public Health describes as a “double burden of malnutrition” where undernutrition and obesity occur side by side. In Cameroon, he sees schools as the best environment to promote healthier diets. “School is really the perfect platform to target adolescents,” he says. “There you have all that it takes to build obesity, and also to unbuild obesity.”

With support from the World Diabetes Foundation, Cameroon has worked to reduce ultra-processed foods and sugary drinks in school environments. The results surprised even those running the programme, with children asking for a day without sugar, leading to “Sugar-Free Thursday” in schools across the country. The Ministry of Secondary Education has committed to making it national policy.

Obesity prevention must begin before a child is born, argues Sanne Frost Helt, director at the World Diabetes Foundation. "When we look at pregnancy as a window, it can be used much more intentionally to unlock so many more health benefits, preventing future obesity, preventing future diabetes in both mother and child," she says. Pre-pregnancy counselling, antenatal care, breastfeeding support, and infant feeding advice are all opportunities to act before disease appears.

Long-term consequences

Children with obesity are likely to become adults with obesity, and the medical consequences can quickly become apparent. At the World Health Assembly, delegates approved a resolution recognising steatotic liver disease, formerly known as fatty liver disease, as a growing contributor to NCDs.

The condition is closely linked to obesity, explains Larry Holden, president and CEO of the Global Liver Institute. "Steatotic liver disease is not just about the liver; it is a cardiometabolic condition closely linked to obesity, diabetes, and cardiovascular disease.” He stresses that these conditions can no longer be treated in isolation or in separate clinical silos.

GLP-1 drugs can improve the lives of people with obesity, but should not become a substitute for prevention, especially among children and adolescents. Photo: Antonius Ferret

Into this landscape has arrived a new and powerful commercial force. GLP-1 drugs, first developed for diabetes and now widely prescribed for weight loss, can help some people with severe obesity. But several experts warn that treatment cannot become a substitute for prevention, especially for children and adolescents.

“There is a huge market—around 1 billion potential customers living with obesity,” Brero says, explaining that he is concerned the drugs could become an easier political answer. “GLP-1s are very important. They can save lives and really improve the lives of people with this chronic condition. But they should not become the easy solution: ‘I can eat junk food, and then I take the medicine.'”

The risk is that the pharmaceutical answer becomes more politically convenient than confronting the food industry, leaving children caught between one industry selling cheap, ultra-processed foods through invisible digital marketing, and another offering expensive medicines to treat the consequences, with national health systems left to pay for both.

"The fact that profit and not health is really driving the [food] products being produced means that pressure for stronger action is likely to grow," Engelhardt emphasises.