It’s not just America: Obesity, a disease of poverty, has swept the world

Not long ago, obesity was popularly considered a disease of affluence — the product of excess and overindulgence. Today, obesity is increasingly recognized as a disease of poverty, rooted in inequality and linked to undernutrition in the earliest years of life.

Obesity is rising fastest in the places least equipped to deal with it. More than 70 percent of overweight and obese people now live in low- and middle-income countries. In countries like Myanmar, Somalia and the Democratic Republic of Congo, obesity rates in adult women already range between 11 and 25 percent. 

This rise is contributing to a dangerous surge in non-communicable diseases, including diabetes, hypertension and cancer. Treating type 2 diabetes and cardiovascular disease — much of it linked to excess consumption of sugar, salt and trans fats — already consumes a growing share of national health budgets.

In 2020, global obesity was estimated to cost nearly $2 trillion. It is expected to rise to over $3 trillion by 2030 and hit $18 trillion by 2060 — which would be equivalent to 3.3 percent of global GDP.

This is not simply about food choices. It is about the environments in which those choices are made. 

For a street vendor, selling an ultra-processed snack with a long shelf life and guaranteed demand is often far more viable than selling fresh fruit or vegetables that will spoil within days. For a struggling family, cheap calorie-dense foods are more affordable than nutrient-rich options.

If we are to turn the tide, we must tackle the structural drivers of the inequalities that foster poor diets and unhealthy food environments.

A focus on the need for preventative strategies is underlined in the 2024 Food-Based Dietary Guidelines on Healthy Diets published by the World Health Organization and the Food and Agriculture Organization. They emphasize the need to shift consumption patterns towards diverse, nutritious foods and away from ultra-processed products that are fueling this epidemic.

Practical measures that we know work include fiscal policies such as taxes on sugar-sweetened beverages, subsidies for fresh fruits and vegetables, clear nutrition labeling and strict limits on the marketing of ultra-processed foods to children. Another measure is to prioritize adequate infant nutrition, including breastfeeding, which can reduce the likelihood of obesity later in life.

Prevention can also be fostered through public procurement policies in schools and hospitals, for instance, to model and promote healthy diets, ensuring that public institutions become enablers of good nutrition rather than conduits for unhealthy products. 

Another piece of the puzzle that is too often overlooked is social protection. School meal programs, for example, not only ensure that children eat at least one nutritious meal a day but also help shape healthy eating habits for life. When linked to local farmers, these programs can strengthen food systems from the ground up. 

Similarly, public procurement and nutrition-sensitive cash transfers can reduce families’ reliance on cheap, ultra-processed foods and make healthier options more accessible and desirable.

In other words, tackling obesity requires us to see it not only as a health issue affecting developed countries but also as a social justice issue for those in developing countries. The social determinants of health — from education to income security to access to affordable, nutritious food — must be addressed if we are to prevent the next generation from facing a lifetime of diet-related disease.

As assistant secretary-general of the United Nations, I recognize the recent U.N. Declaration on Non-Communicable Diseases is an important step forward. 

But to make a real difference, countries must go further, explicitly adopting WHO-recommended measures to reshape food systems and embedding nutrition into social protection frameworks. Without fiscal policies and stronger safeguards against the marketing of unhealthy foods, especially to children, the declaration risks missing its mark.

By 2030, more than 1.2 billion adults are projected to live with obesity, and 5.7 percent of children under age 5 are expected to be overweight. These numbers represent futures cut short, health systems overwhelmed and societies weighed down by preventable disease.

The solutions are within reach — but only if governments act decisively to reshape food environments, strengthen social protection and put people, not profit, at the center of our food systems.

The cost of inaction is counted not only in dollars, but in lives. The world can no longer afford to ignore it.

Afshan Khan is assistant secretary-general of the United Nations and coordinator of the Scaling Up Nutrition Movement.