In the 1990s, an overweight or obese child was considered an exception. Today, it’s slowly becoming the norm. A sweeping new study published in The Lancet lays bare a disturbing reality: the prevalence of childhood and adolescent obesity has tripled since 1990 and shows no signs of slowing down. If current trends continue, by 2050, 360 million children and young people worldwide will be living with obesity​. Essentially, one in three children will be overweight and obese.

This shift isn’t just about kids getting a little chubbier. It’s a public health crisis with profound consequences. Once obesity is established in childhood, it rarely reverses. It brings with it a cascade of health problems — diabetes, heart disease, infertility — and economic burdens that will send ripples through healthcare systems across the globe.

How did we get here?

For decades, obesity was seen as a problem of affluence — more common in wealthier nations where processed foods and sedentary lifestyles were abundant. But today’s data shows that’s no longer the case.

The first problem is ultra-processed diets. Calorie-dense, and nutrient-poor foods have become staples in households worldwide. Oftentimes, these foods (including burgers and sodas) are also quite cheap. In fact, studies show that ultra-processed diets rich in calories but poor in essential nutrients are oftentimes cheaper than their healthier counterparts.

The second problem is our sedentary lifestyle. For kids, screen time has replaced outdoor play, and physical activity in schools has declined. Lastly, this is all compounded by advertising. Junk food advertising targets children aggressively, while urbanization makes fresh, unprocessed foods less accessible.

While some measures (like sugar taxes) can make an impact, the world is largely failing on childhood obesity, with almost no exceptions.

The most affected areas

The new study analyzed 1,321 datasets from 180 countries, tracking trends from 1990 to 2021 and forecasting to 2050. The results showed that while obesity is still highest in high-income regions like North America and Australasia, the most dramatic increases are occurring elsewhere​.

Overall, the number of overweight or obese people worldwide rose from 929 million in 1990 to 2.6 billion in 2021. The current forecast is that 3.8 billion adults (almost 60% of the population) will be overweight or obese within the next 15 years.

For kids, things aren’t much better. In North Africa and the Middle East, obesity rates among children and adolescents have surged by more than 400% since 1990. One of the study’s most startling findings is that, in these regions, obesity is set to overtake overweight as the dominant category among children​.

Regions that were historically more linked to undernutrition are also becoming havens for obesity. Many children in these regions experience a “double burden of malnutrition”, where undernutrition (stunting, wasting, and micronutrient deficiencies) coexists with rising obesity rates. This paradox is driven by food insecurity and poor diet quality, where families rely on cheap, ultra-processed, calorie-dense foods that lack essential nutrients. As a result, children who were once undernourished in early life are more likely to develop obesity later, as their bodies adapt to cycles of deprivation and excess, increasing the risk of metabolic diseases. This shift is particularly evident in South Asia and Sub-Saharan Africa, where childhood undernutrition remains a concern even as obesity rates surge​.

Time is running out

Study author Dr. Jessica Kerr said if immediate, five-year action plans aren’t developed, the future is bleak for our youth. We could be even facing a “lost generation” health-wise.

“Children and adolescents remain a vulnerable population within the obesity epidemic,” she said. Prevention is key as obesity rarely resolves after adolescence.

“This giant burden will not only cost the health system and the economy billions, but complications associated with a high Body Mass Index (BMI), including diabetes, cancer, heart problems, breathing issues, fertility problems and mental health challenge, will negatively impact our children and adolescents now and into the future, even holding the potential to impact our grandchildren’s risk of obesity and quality of life for decades to come.

Tackling childhood obesity requires a multi-pronged approach, but it can be done. The first (and in principle, the simplest) measure is implementing stronger regulations on food marketing. Junk food companies target children relentlessly. Countries like Chile and the UK have implemented restrictions on advertising unhealthy foods to kids with promising results. An “unhealthy” tax on fast foods could also have an important impact. However, fast food companies are likely to lobby and fight against such measures.

Incentivizing physical activity, educating families, and supporting healthy school meals can also make a difference, but these approaches will be more challenging to implement. Dr Kerr says that adolescent girls, particularly those aged 15-24 years, who are entering their reproductive years, were a priority population for intervention.

“Adolescent girls who are obese are a main focus if we are to avoid intergenerational transmission of obesity, chronic conditions and the dire financial and societal costs across future generations,” she said. “With this age group increasingly being out of school and cared for by adult services, we need to focus interventions at the community and commercial level.”

We need governments to step in

Researchers emphasize that putting this challenge on individual people and their decisions won’t solve anything. These are systemic problems.

Professor Susan Sawyer says we need governments to invest in strategies that reduce obesity drivers if we don’t want the problem to keep getting worse and worse.

“Given this huge global shift in children’s and adolescents’ weight, we can no longer keep blaming people for their choices. We require governments to step up by addressing regulatory interventions including taxing sugar sweetened beverages, banning junk food advertising aimed at children and young people and funding healthy meals in primary and secondary schools. We also need to consider the benefits of wider policies such as overhauling urban planning to encourage active lifestyles.”

While childhood obesity is set to increase across the board, some countries in Northern and Western Europe (such as Scandinavia and Germany) are projected to have lower rates. This is due to better nutrition policies, stricter food regulations, and a culture that encourages physical activity. European nations have already taken steps like junk food advertising restrictions and school meal reforms, which could help slow the epidemic.

The next five years are critical. Without immediate intervention, we’re not just setting up millions of children for a lifetime of health problems — we’re shaping a future where obesity is an inescapable reality for generations to come.

Journal Reference: ‘Global, regional, and national prevalence of child and adolescent overweight and obesity, 1990-2021, with forecasts to 2050: a forecasting study for the Global Burden of Disease Study 2021,’ The Lancet.