Every year on 7 April, the world marks World Health Day, a global initiative led by the World Health Organization (WHO) to highlight major health challenges and promote action to improve public health. In 2026, the theme is “Together for health. Stand with science.” The campaign encourages governments, scientists, health workers, and the public to support science-based solutions to protect the health of people, animals, and the planet (1).

Scientific advances have transformed global health and have saved millions of lives. One of the clearest examples is the rise in life expectancy. In 1900, the average life expectancy of a newborn worldwide was only 32 years. By 2021, it had increased to about 71 years (2). More recent data show the same trend. Global life expectancy rose from 51 years in 1960 to 73 years in 2023 (3), while in South Africa it increased from 53 years in 1960 to 66 years in 2023 (4). At the same time, science progresses by continuously questioning and refining existing knowledge. On this World Health Day, we at The Noakes Foundation want to emphasise that standing with science also means asking critical questions, especially in areas such as nutrition where scientific understanding continues to evolve.

To understand why questioning science is important, it is helpful to understand what science actually is. Science is not a fixed collection of facts. It is a method of learning about the world through observation, forming hypotheses, testing ideas, repeating experiments, and revising conclusions when new evidence emerges. Scientific knowledge, therefore, evolves, and debate, replication, and openness to new data are essential parts of this process (5). Health sciences apply this scientific approach to understand the human body, improve wellbeing, and strengthen healthcare systems (6).

Because science evolves, many ideas that were once widely accepted were later revised or replaced when better evidence became available. In medicine, for example, doctors once believed disease was caused by imbalances in the body’s four humors, which led to treatments such as bloodletting. Another example is the miasma theory, which suggested diseases spread through “bad air” before germ theory demonstrated that microorganisms cause infectious disease (7).

Nutrition science has also evolved as researchers continue to learn more about the relationship between diet and health. Dietary guidelines have been revised repeatedly over the past century as scientific understanding changes (8). One well-known example is the food pyramid, a visual guide showing recommended daily servings from different food groups. The first version was introduced in Sweden in 1974. In 1992, the United States released the “Food Guide Pyramid,” which was later updated to “MyPyramid” in 2005 and replaced by “MyPlate” in 2011. In January 2026, the United States introduced an inverted version of the food pyramid (9). The repeated revisions of these guidelines illustrate an important principle. Scientific progress depends on continually questioning and reassessing existing recommendations as new evidence emerges.

However, nutrition science is one of the most complex areas of health research (10). Current dietary recommendations from major health organisations still emphasise carbohydrates as the primary source of energy in the human diet. According to the WHO, carbohydrates should make up approximately 45% to 75% of total daily energy intake, while fat intake is generally recommended to remain below 30% of total daily energy (11). Many food-based dietary guidelines and food pyramids similarly place grains and other carbohydrate-rich foods at the foundation of a healthy diet (12). Yet despite decades of such guidance, metabolic diseases continue to rise globally. Obesity rates have increased sharply over the past three decades. Since 1990, adult obesity has more than doubled, and adolescent obesity has increased about four times. (13). What was once largely considered a problem in high-income countries has now become a global health challenge. In South Africa, nearly half of all adults, 49.8%, are overweight or obese. Among men, the prevalence is 31.3%, while among women it is 67.6% (14), with national rates now significantly higher than global averages (15).

The consequences are visible in the rising burden of metabolic diseases. In 2021, a higher than optimal body mass index (BMI) was associated with an estimated 3.7 million deaths from non-communicable diseases (NCDs), including cardiovascular disease, type 2 diabetes, and certain cancers (13). Diabetes in particular has increased rapidly. Global prevalence roughly doubled from about 7% in 1990 to around 14% in 2022, with South Africa reaching 13.9% in 2022 (16). The number of people living with diabetes is expected to increase further in the coming decades (17).

Research also shows that dietary patterns have changed significantly in many regions, including Southern Africa, where diets increasingly contain more refined carbohydrates, sugars, and energy-dense foods (18). This nutrition transition has been linked to rising rates of obesity and other NCDs, highlighting the important role that diet plays in long-term metabolic health (11).

These global trends raise an important question: are current dietary guidelines sufficient to address the growing burden of metabolic disease, or might they need to evolve? At The Noakes Foundation, this is exactly what we mean by questioning the science. If obesity, diabetes, and other metabolic diseases continue to rise despite existing South African guidance, it becomes important to critically examine whether current approaches are truly addressing the root of the problem.

While medications such as antihypertensive drugs for high blood pressure and insulin for high blood sugar are essential treatments for many people, they manage symptoms rather than the underlying causes of metabolic disease. Addressing the root drivers of poor metabolic health is important not only for those already living with these conditions but also for preventing them in the first place. A growing body of research shows that dietary change can significantly improve metabolic health and even help some people manage or reverse type 2 diabetes (19).

This is why we at The Noakes Foundation promote questioning current nutrition guidance and support a Low Carbohydrate High Fat (LCHF) real food lifestyle. By reducing carbohydrates and sugars while prioritising nutrient-dense whole foods, this approach aims to improve blood sugar control and overall metabolic health. It also places real food back at the centre of the plate and encourages reducing the consumption of ultra-processed foods that increasingly dominate modern diets. Questioning dietary guidelines does not mean rejecting science. On the contrary, it reflects how science progresses. Nutrition science continues to evolve, and new evidence should always be examined critically. Just as dietary guidelines and food pyramids have changed over time, current recommendations should remain open to evaluation and improvement. This means being willing to reassess all ideas and frameworks as better evidence becomes available.

Today, the world faces a global epidemic of chronic lifestyle-related diseases. Obesity, diabetes, and other metabolic conditions represent one of the greatest public health challenges of our time (20). Addressing this crisis requires scientific progress, open discussion, and the willingness to re-examine long-held assumptions about diet and health.

The theme of World Health Day 2026 reminds us to stand with science. But standing with science does not mean treating scientific knowledge as final. It means staying curious, engaging with evidence, and encouraging open debate. Science has improved human health in extraordinary ways, and it works best when it remains transparent and open to new ideas.

On this World Health Day, standing with science means continuing to question, learn, and improve in the pursuit of better health for everyone.

Raja Pfisterer is a qualified nurse from Basel, Switzerland, currently pursuing a Master’s degree in Health Sciences with a major in Economics and Policy at the University of Lucerne. She combines clinical nursing experience with a strong interest in public health and is passionate about linking health and nutrition to support individual wellbeing and more sustainable healthcare approaches.

Raja is currently interning with The Noakes Foundation in Cape Town, where she is gaining practical experience in public health and learning about nutritional approaches to chronic disease in under-resourced communities through Eat Better South Africa.

Her interests include health equity, strengthening sustainable healthcare systems, and developing public health policy interventions that improve health outcomes while promoting health literacy and empowering individuals to take an active role in their own well-being. She hopes to dedicate her future career to understanding the social determinants of health, addressing health inequalities, and improving population health, particularly among vulnerable groups.

Through her work with The Noakes Foundation, Raja believes people can be empowered to take control of their health step by step, helping build healthier communities and support long-term well-being.

References

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2. Ritchie, H., Spooner, F., & Roser, M. (2024). Life expectancy. Our World in Data. https://ourworldindata.org/life-expectancy
3. World Bank. (2024). Life expectancy at birth, total (years). https://data.worldbank.org/indicator/SP.DYN.LE00.IN
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11. World Health Organization. (2026). Healthy diet. https://www.who.int/news-room/fact-sheets/detail/healthy-diet
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14. World Obesity Federation. (2026). South Africa data. Global Obesity Observatory. https://data.worldobesity.org/country/south-africa-197/
15. Africa Check. (2024). How does South Africa’s obesity rate compare globally? https://africacheck.org/infofinder/explore-facts/how-does-south-africas-obesity-rate-compare-globally
16. World Health Organization. (2024). Prevalence of diabetes, age standardized. Global Health Observatory. https://www.who.int/data/gho/data/indicators/indicator-details/GHO/prevalence-of-diabetes-age-standardized
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19. Hallberg, S. J., McKenzie, A. L., Williams, P. T., Bhanpuri, N. H., Peters, A. L., Campbell, W. W., Hazbun, T. L., Volk, B. M., McCarter, J. P., Phinney, S. D., & Volek, J. S. (2018). Effectiveness and safety of a novel care model for the management of type 2 diabetes at one year: An open label, non randomised controlled study. Diabetes Therapy, 9, 583–612. https://doi.org/10.1007/s13300-018-0373-9
20. World Health Organization. (2025). Noncommunicable diseases. https://www.who.int/news-room/fact-sheets/detail/noncommunicable-diseases