Global study reveals obesity has overtaken being underweight among the world’s young

Key Takeaways:

• For the first time in recorded data, there are more children and adolescents living with obesity than those who are underweight, according to UNICEF.
• Nearly one in ten young people aged 5–19 years – around 188 million globally – are now affected by obesity, driven largely by the rise in consumption of ultra-processed foods.
• UNICEF is calling for urgent government action to protect children’s diets, restrict the influence of the ultra-processed food industry on policymaking, and make nutritious foods affordable and accessible.
  

A historic shift in global child health

For the first time, the number of children and adolescents worldwide living with obesity has surpassed the number who are underweight. This milestone, highlighted in a major study by UNICEF, underscores a profound transformation in global nutrition and public health.

The study found that approximately one in ten young people aged between 5 and 19 years – an estimated 188 million individuals – are now living with obesity. This represents a sharp increase compared with the early 2000s. Researchers attribute this shift primarily to the replacement of traditional diets with ultra-processed foods that are inexpensive, calorie-dense, and nutritionally poor.

Redefining malnutrition

Historically, malnutrition in children was almost synonymous with underweight and hunger. Today, the definition is broader, encompassing not only wasting and stunting but also the growing prevalence of overweight and obesity.

Children are classified as overweight when their weight significantly exceeds the healthy range for their age, sex, and height. Obesity is recognised as the more severe form of overweight and is associated with an elevated risk of type 2 diabetes, cardiovascular disease, and some cancers in later life.

Good nutrition throughout childhood – including adequate intake of fruit, vegetables, and protein – is vital for healthy growth, cognitive development, and mental wellbeing. Yet many of these traditional sources of nourishment are being replaced by foods laden with sugar, starch, salt, unhealthy fats, and artificial additives.

UNICEF’s Executive Director, Catherine Russell, warned that the dangers posed by this trend must not be underestimated. She described obesity as “a growing concern” that has significant implications for the health and development of children.

Rising obesity, declining underweight

The UNICEF-backed study, which analysed data from over 190 countries, highlights two diverging global trends. Between 2000 and 2022, the proportion of children aged 5–19 years who were underweight declined from nearly 13 per cent to 9.2 per cent. At the same time, obesity rates rose steeply from 3 per cent to 9.4 per cent.

This means that almost one in ten children worldwide is now living with obesity. When combining overweight and obesity, the figures are even more striking: one in five school-aged children and adolescents – around 391 million globally – is above a healthy weight.

Although underweight remains a pressing concern in children under the age of five, particularly in low and middle-income countries, obesity is increasingly the dominant nutritional challenge for those aged 5–19. The only regions where underweight still exceeds obesity are sub-Saharan Africa and South Asia.

Geographic hotspots and global distribution

The prevalence of childhood obesity is particularly acute in certain regions. Pacific Island nations have some of the highest rates, including Niue (38 per cent), the Cook Islands (37 per cent), and Nauru (33 per cent).

High-income countries are not exempt. In Chile, 27 per cent of 5–19-year-olds live with obesity, while in the United States and the United Arab Emirates the figure stands at 21 per cent.

“This double burden of malnutrition – the existence of both stunting and obesity in the same populations – requires targeted interventions,” Catherine Russell explained. “Nutritious and affordable food must be available to every child to support their growth and development. We urgently need policies that support parents and caretakers to access nutritious and healthy foods for their children.”

The call to action

The UNICEF report highlights the potentially devastating health and economic consequences of inaction. By 2035, the global economic burden of overweight and obesity is projected to exceed US$4 trillion (£2.95 trillion) per year.

To mitigate these risks, UNICEF has called upon governments to implement robust policies. These include:

• Restricting unhealthy foods – such as removing ultra-processed products from school canteens and regulating food labelling and marketing to children.
  
• Introducing fiscal measures – for example, taxing sugar-sweetened beverages and other unhealthy products, while incentivising healthier options.
  
• Encouraging reformulation – compelling food manufacturers to reduce unhealthy ingredients such as excess salt, sugar, and harmful fats.
  
• Safeguarding policy from industry influence – ensuring that ultra-processed food and drink producers are excluded from developing or implementing public health policy. Any lobbying efforts would need to be transparently reported.
  

A global imperative

The findings mark a pivotal moment in global health, emphasising the urgent need for a coordinated response. The steady replacement of traditional diets with ultra-processed foods has triggered a nutrition crisis that spans continents and income levels.

Without decisive policy action, the health outcomes for millions of children and the economic burden for societies will only worsen. UNICEF’s call is clear: protecting children’s diets from the pervasive influence of ultra-processed food industries and ensuring access to affordable, nutritious foods must become a global priority.

CCH Insight:

These statistics highlight an interesting phenomenon occurring in some developing countries, such as India, China and Nigeria. As these countries develop economically, they are grappling with the dual challenge of undernourished, underweight children in poor, mostly rural areas, and childhood obesity amongst the more affluent, who have adopted a western, processed food diet, mostly in urban areas. Due to the populous nature of these countries, global childhood obesity rates are likely to continue to rise for many years to come, unless a concerted effort is made to regulate food processing, as suggested by the authors. Unfortunately, the food industry is a very powerful lobby, that makes these kind of policies very difficult to adopt.