Childhood Obesity: Everything You Should Know

Childhood obesity used to be described as a problem of wealthy countries. That’s no longer true. Today, it is one of the most common health conditions affecting children worldwide – and it is growing fastest in low- and middle-income countries like Kenya.

According to recent UN and WHO estimates, more than 390 million children and adolescents aged 5 – 19 years were living with overweight in 2022, and roughly one in five in this age group is now above a healthy weight for their age.

For the first time in history, global analyses now suggest that more school-aged children are obese than underweight. In other words, the world has not solved malnutrition, but obesity has already overtaken it in many age groups.

The rise has been dramatic. In 1990, only around 8% of 5 – 19-year-olds worldwide were overweight. By 2022, that figure had climbed to about 20%. Childhood obesity is not a minor side issue; it is now a central driver of the global epidemic of non-communicable diseases (NCDs) such as type 2 diabetes, heart disease and some cancers.

Related Topics on Obesity

What’s driving childhood obesity globally?

Experts are clear: this is not simply about “children eating too much”. It is about the environments children are growing up in.

1. Food environments flooded with ultra-processed foods (UPFs)
   Supermarkets, kiosks, and even school canteens are increasingly dominated by ultra-processed snacks, sugary drinks and fast foods. These products are cheap, aggressively marketed and engineered to be highly palatable. UNICEF and WHO have highlighted that the rapid expansion of these products – and their marketing to children – is a major engine of childhood obesity.
   
2. Less movement, more screens
   Urbanisation, unsafe play spaces, long school days, academic pressure and the pull of digital entertainment mean many children do not reach the recommended 60 minutes of moderate to vigorous physical activity per day. Screen time has increased sharply, especially after the COVID-19 pandemic.
   
3. Early-life and family factors
   A child’s risk of obesity starts before birth. Maternal overweight, gestational diabetes and rapid “catch-up” growth after early undernutrition all increase the likelihood of obesity later in life. Studies from African and Asian countries show that children of mothers with overweight or obesity are significantly more likely to have obesity themselves.
   
4. Social and economic pressures
   In many low- and middle-income countries, we now see the “double burden of malnutrition”: children can be stunted in early life and then become overweight or obese later, especially when cheap ultra-processed foods are easier to access than fresh produce. Healthy food is often more expensive and harder to find than unhealthy options.
   

Why does childhood obesity matter so much?

Obesity in childhood is not just a cosmetic issue. Children with obesity face both immediate and long-term health risks.

• They are more likely to have high blood pressure, abnormal cholesterol, insulin resistance, type 2 diabetes and fatty liver disease before they even leave school.
  
• Many experience sleep apnoea, joint problems and asthma, as well as earlier puberty and menstrual irregularities in girls.
  
• The psychological impact is significant: bullying, low self-esteem, depression and anxiety are far more common in children living with obesity than in their peers.
  

Perhaps most importantly, obesity in childhood tends to track into adulthood. A teenager with obesity has a high chance of becoming an adult with obesity, facing a lifetime of increased risk of heart disease, stroke, certain cancers, fertility issues and reduced life expectancy. 

Economists are now warning that obesity already costs countries about 2% of GDP on average through healthcare spending and lost productivity – a figure expected to rise if current trends continue. 

Bringing the picture closer to home: Kenya

So where does Kenya fit in this global story?

For many years, Kenya’s main nutrition concerns were undernutrition, stunting, and micronutrient deficiencies. Those problems are still very real. But in the last two decades, a quiet shift has been taking place, particularly in urban areas.

National survey data show that around 3 to 4% of Kenyan children under five are now overweight. That may sound small compared to high-income countries, but it is rising – and it co-exists with high rates of stunting and anaemia.

Analysis of Kenya’s Demographic and Health Survey data shows that: 

• Overweight is more common in urban settings than rural ones.
  
• Children from wealthier households are more likely to have overweight than those from poorer households.
  
• There is a strong link between maternal weight and child weight – children of mothers with overweight or obesity are themselves more likely to be overweight.
  

In Nairobi, Mombasa and other major towns, the pattern is familiar:

• Schoolchildren have easy access to sugary drinks, chips, mandazi, sausages and confectionery just outside the school gate.
  
• Many estates have limited safe play spaces; children may spend long hours sitting in class, in traffic, or on screens at home.
  
• Fresh fruits, vegetables and quality protein are often more expensive than a plate of chips and soda.
  

Kenya therefore faces a double challenge: continuing to combat undernutrition in some regions, while preventing a new wave of obesity-related NCDs in others.

What can be done?

Globally, experts are clear that tackling childhood obesity requires more than telling children to “eat less and move more.” Key strategies include:

• Healthier food environments: policies that make sugary drinks and ultra-processed foods less attractive (for example, through taxes, restrictions in and around schools, clear front-of-pack labelling) and make healthier foods more available and affordable.
  
• School-based action: strong school feeding standards, banning sugary drinks in canteens, building time for daily physical activity, and involving parents in nutrition education.
  
• Support for families: practical coaching on meal planning, portion sizes, screen time limits and sleep routines; and recognition that families need support, not blame.
  
• Clinical care when needed: child obesity is now recognised as a chronic disease, not a personal failure. International guidelines recommend structured lifestyle programmes as first-line treatment, and in severe cases, carefully supervised medication or bariatric surgery for adolescents may be considered.
  

For Kenya, this means integrating obesity prevention into existing programmes – from maternal and child health clinics to school health, urban planning and national NCD strategies. It also means shifting our language: away from shame and blame, and towards seeing obesity as a real, treatable medical condition shaped by biology and environment.

Childhood obesity is no longer a distant problem in faraway countries. It is here with us, evolving alongside our cities, our food systems and our lifestyles. The good news is that the same changes that protect children from obesity – safer places to play, access to healthy food, supportive schools and informed families – also build a healthier, more productive Kenya for everyone.