Obesity exceeds underweight for the first time among school-age children and adolescents globally – UNICEF

PRETORIA, 10 September 2025 – Obesity surpassed underweight as the more prevalent form of malnutrition this year, affecting 1 in 10 – or 188 million – school-aged children and adolescents, and placing them at risk of life-threatening disease, the United Nations Children’s Fund (UNICEF) warned in a new report today. 

The report, titled Feeding Profit: How Food Environments are Failing Children, draws on data from over 190 countries, including South Africa, and finds that while the prevalence of underweight among children aged 5-19 has declined since 2000, (from nearly 13% to 9.2%), obesity rates have increased from 3% to 9.4%. Obesity now exceeds underweight in most regions of the world.

“Childhood overweight and obesity represent a significant public health challenge in South Africa,” says Gilbert Tshitaudzi, Nutrition Manager at UNICEF South Africa. The data for South Africa is concerning, showing that the percentage of overweight and obesity in children under 5 years rose from 13% in 2016 to 23% in 2024. 

In addition, the percentage of overweight children in South Africa (aged 5 to 19) rose from 9% in 2000 to 21% in 2022.  While it is encouraging that the number of children (aged 5 to 19) with underweight issues (thinness) decreased from 12% in 2000 to 3% in 2022, the percentage of children with obesity rose from 2% to 7% over this period.

Ultra-processed food is increasingly replacing fruits, vegetables and protein at a time when nutrition plays a critical role in children’s growth, cognitive development and mental health. While undernutrition – such as wasting and stunting – remains a significant concern among children under 5 in most low- and middle-income countries, the prevalence of overweight and obesity is increasing among school aged children and adolescents.

According to the latest available data, 1 in 5 children and adolescents aged 5-19 globally – or 391 million – are overweight, with a large proportion of them now classified as living with obesity.

Children are considered overweight when they are significantly heavier than what is healthy for their age, sex and height. Obesity is a severe form of overweight and leads to a higher risk of developing insulin resistance and high blood pressure, as well as life-threatening diseases later in life, including type-2 diabetes, cardiovascular disease, and certain cancers.

The report warns that ultra-processed and fast foods – high in sugar, refined starch, salt, unhealthy fats and additives – are shaping children’s diets through unhealthy food environments, rather than personal choice. These products dominate shops and schools, while digital marketing gives the food and beverage industry powerful access to young audiences. 

For example, in a global poll of 64,000 young people aged 13-24 from over 170 countries conducted through UNICEF’s U-Report platform last year, 75 per cent of respondents recalled seeing advertisements for sugary drinks, snacks, or fast foods in the previous week, and 60 per cent said the advertisements increased their desire to eat the foods.

Without interventions to prevent childhood overweight and obesity, countries could face lifetime health and economic impacts By 2035, the global economic impact of overweight and obesity is expected to surpass US$4 trillion annually. 

The report highlights positive steps governments have taken to transform food environments and makes several recommendations including: 

• Implement comprehensive mandatory policies to improve children’s food environments, including food labelling, food marketing restrictions, and food taxes and subsidies.
• Implement social and behavior change initiatives that empower families and communities to demand healthier food environments.
• Ban the provision or sale of ultra-processed and junk foods in schools and prohibit food marketing and sponsorship in schools.
• Establish strong safeguards to protect public policy processes from interference by the ultra-processed food industry.
• Strengthen social protection programmes to address income poverty and improve financial access to nutritious diets for vulnerable families.

Noting the increasing commitment by the Government of South Africa to address this critical issue, Gilbert Tshitaudzi from UNICEF emphasizes that “nutritious and affordable food must, as a matter of urgency, be available to every child to support their growth and development”.

Notes for editors:

The Child Nutrition Report 2025 draws on data from over 190 countries and includes household surveys, modelled estimates, projections, and polls. Data on overweight, stunting and wasting among children under the age of 5 from 2000-2024 are based on UNICEF/WHO/World Bank Joint Child Malnutrition estimates.

For children and adolescents aged 5-19 years, data on overweight, obesity and underweight is modelled using population-based surveys, administrative data or studies that measured height and weight in representative samples.

Country level data is available from 2000-2022 and coordinated by the Non-Communicable Disease Risk Factor Collaboration (NCD-RisC). 

To ascertain obesity surpassing underweight among children aged 5-19 years, UNICEF projected prevalence from 2022 onwards, based on trends in prevalence of obesity and underweight from 2010 to 2022.

Categories of overweight, obesity and underweight (thinness) are defined based on body mass index (BMI).  Child malnutrition has three dimensions: undernutrition (stunting and wasting), overweight/obesity and hidden hunger or micronutrient deficiencies.

Ultra-processed foods are industrially formulated foods and beverages made primarily from refined ingredients and additives, with little or no whole foods. They contain high levels of added sugars, refined starches, salt, and unhealthy fats, and are designed to be convenient, highly palatable, and appealing through marketing, packaging, and branding.