South Africa’s 12 million reasons to act: The hidden cost of inaction on obesity

South Africa faces a growing health crisis that remains largely overlooked in national policy debates. While the country has made significant progress in tackling infectious diseases such as HIV and tuberculosis, another threat is expanding quietly alongside them: obesity and the wave of chronic illnesses that follow in its wake.

Around 12 million South African adults live with obesity, and the number continues to rise. More than half of adults are now overweight or obese. Among women, the burden is particularly severe, with more than two-thirds affected. According to the World Obesity Federation, these trends place South Africa among the countries with the highest obesity rates in sub-Saharan Africa.

Obesity is not simply a matter of personal lifestyle. It is a chronic disease associated with more than 200 medical complications, including cardiovascular disease, type 2 diabetes and several cancers. As prevalence rises, so too does the pressure on healthcare systems, public finances and economic productivity.

South Africa’s challenge is especially complex because it carries what public health experts describe as a double burden of disease. Infectious diseases such as HIV and tuberculosis remain major health challenges, while non-communicable diseases linked to obesity and metabolic dysfunction are increasing rapidly. Managing both simultaneously places significant strain on the healthcare system.

The economic costs are already substantial. Health economics research estimates that obesity cost South Africa approximately R33.2 billion in 2020, equivalent to about 15% of government health expenditure and roughly 0.67% of GDP. In the private sector, medical schemes incurred an additional R21.8 billion in obesity-related costs in 2022, driven largely by associated conditions such as diabetes, hypertension, heart disease and stroke.

Beyond healthcare spending, the economic burden manifests through lost productivity, absenteeism and early retirement due to chronic illness and disability. Employers absorb these costs through reduced workforce performance, while the state faces increasing fiscal pressure through healthcare and social support programmes.

The drivers of obesity are deeply intertwined with broader social and economic conditions. Food affordability is a major factor. Analyses of household spending show that the average monthly cost of a basic food basket often exceeds the income of many low-income workers. For many families, healthier food choices remain financially out of reach.

The result is a troubling paradox in which food insecurity and obesity coexist. Households facing economic constraints often rely on cheaper, calorie-dense foods high in sugar, salt and refined carbohydrates. These foods provide low-cost energy but contribute to long-term metabolic disease.

Urbanisation further compounds the problem. As cities expand, physical activity often declines while access to highly processed foods increases. At the same time, many communities lack safe public spaces for exercise, making healthier lifestyles harder to maintain.

The consequences are increasingly visible. South Africa now has approximately 4.6 million adults living with type 2 diabetes, a condition strongly associated with obesity and metabolic dysfunction and now among the country’s leading causes of death.

For decades, obesity was framed largely as a matter of personal responsibility, with public health campaigns focused primarily on diet and exercise. While these factors remain important, that perspective is now widely recognised as incomplete. Obesity is a complex chronic disease influenced by genetics, metabolism, environment and socio-economic conditions.

Addressing it therefore requires a comprehensive response.

Fiscal policy can play an important role. South Africa’s Health Promotion Levy, commonly referred to as the sugar tax, was introduced in 2018 to reduce sugar consumption and encourage healthier beverage choices. Research published in The Lancet suggests the levy has contributed to reductions in sugar purchases and product reformulation by beverage manufacturers. However, fiscal measures alone cannot solve the problem.

Additional evidence shows the levy also encouraged product reformulation and reduced sugar purchases, reinforcing its role as a population-level prevention measure.

Health system capacity also matters. Effective obesity management requires early diagnosis, lifestyle interventions and access to evidence-based treatment. Medicines targeting the glucagon-like peptide-1 (GLP-1) pathway have demonstrated meaningful benefits in managing obesity and type 2 diabetes. Clinical evidence shows weight reductions of around 10–15%, alongside improvements in cardiometabolic health. Medicines are not a substitute for prevention, but they can play an important role as part of comprehensive care.

Yet access to treatment remains uneven. Innovative therapies have emerged in recent years, but their cost and availability often limit access in middle-income countries. Without careful policy design, advances in treatment risk widening health disparities between those who can afford care and those who cannot.

Another barrier is stigma. Research indicates that nearly 69% of people living with obesity report experiencing stigma from healthcare professionals, often discouraging them from seeking medical care. Health systems must adopt more patient-centred approaches that recognise obesity as a chronic disease rather than a personal failing.

South Africa has confronted major health crises before. The country’s response to HIV and COVID-19 demonstrated what is possible when science, policy and community engagement align behind a common goal.

Obesity now demands a similarly ambitious response.

Thus, we have twelve million reasons to act. We must develop a national strategy that integrates prevention, equitable access to novel treatment, and supportive social environments. This isn’t about waistline management. It is about protecting the country’s health, productivity and economic future.

Thabeng Leping is Director of Market Access & Public Affairs at Novo Nordisk South Africa.