Every year on 4 March, World Obesity Day brings together organisations, health professionals, and communities across the globe to raise awareness about obesity and its impact on health (1). Launched in 2015, the campaign is led by the World Obesity Federation, which works in official relations with the World Health Organization (WHO) (2). In 2026, the theme “8 Billion Reasons to Act on Obesity” reminds us that with more than eight billion people worldwide, everyone is affected by this growing crisis (3). It calls for collective action to improve food systems, healthcare, policy, and environments so that healthier choices become easier choices.
To understand why this day matters, we first need to understand what obesity is and how it is measured. Obesity is not simply about body weight. It is defined as an abnormal or excessive accumulation of body fat that increases health risk. The WHO classifies obesity as a chronic, relapsing disease and uses Body Mass Index (BMI) as a screening tool. In adults, a BMI of 25 or higher is classified as overweight, and a BMI of 30 or higher as obesity (4). For children and adolescents, age and sex must also be considered. BMI is calculated by dividing weight in kilograms by height in metres squared (5).
While BMI is widely used, evidence shows that it does not tell the full story. BMI does not fully consider important factors such as sex, age, race, and ethnicity, all of which influence body composition and metabolic risk. For this reason, we at The Noakes Foundation also consider waist circumference an important additional measure, consistent with current literature and international expert consensus (6). Measuring waist size helps assess visceral fat, which is strongly linked to metabolic disease and insulin resistance. By looking beyond BMI alone, we aim to better understand metabolic health.
However, even when BMI is used simply as a broad population-level screening tool, the scale of the global problem becomes clear. Obesity rates have risen sharply over the past three decades. Since 1990, adult obesity has more than doubled, and adolescent obesity has increased four times (7). In 2022, one in eight people globally were living with obesity. That same year, an estimated 2.5 billion adults were overweight, including 890 million living with obesity. This means that 43% of adults worldwide were overweight and 16% were classified as obese (4). The impact is also visible in younger generations. In 2024, 35 million children under the age of five were overweight. In 2022, more than 390 million children and adolescents aged 5 to 19 were overweight, including 160 million living with obesity (4). Obesity is no longer limited to certain regions or income groups. It has become a global health crisis.
While these global figures are concerning, the situation in South Africa is even more serious. Nearly half of all adults, 49.8%, are overweight or obese. Among men, 31.3% are affected. Among women, the number rises to 67.6%, meaning roughly two out of every three women in South Africa are overweight or obese. Of these, 41% of women are living with obesity (8). Between 1998 and 2021, obesity increased by 13.4% in women and 5.2% in men (8). Compared with global averages, South Africa’s rates are significantly higher (9). This shows how urgent it is to address obesity not only as an individual concern, but as a national and global priority.
These rising numbers are not just statistics. They represent real and serious health and economic consequences. The risks linked to overweight and obesity are well established. In 2021, a higher than optimal BMI was associated with an estimated 3.7 million deaths from noncommunicable diseases (NCDs), including cardiovascular disease, type 2 diabetes, certain cancers, neurological disorders, chronic respiratory conditions, and digestive diseases (4).
The impact begins early in life. Children and adolescents living with overweight or obesity face a higher risk of developing these conditions at a younger age and are more likely to experience chronic illness later in life. Beyond physical health, many children also face stigma, discrimination, and bullying. This can affect their mental well-being, school performance, and overall quality of life (4). Children with obesity are also more likely to become adults with obesity, increasing their long-term health risks (10).
The economic burden is equally concerning. If current trends continue, the global cost of overweight and obesity is projected to reach US$ 3 trillion per year by 2030 and more than US$ 18 trillion by 2060 (4). Therefore, what was once considered a problem mainly in high-income countries now affects low- and middle-income nations and vulnerable communities at an increasing rate. Obesity is not only a health issue. It is a global development challenge.
To change this trajectory, we must ask an important question: what is driving this epidemic? At its most basic level, for decades, we have been told that obesity develops when energy intake exceeds energy expenditure. But in reality, the issue is far more complex than calories alone. The WHO describes obesity as a multifactorial disease influenced by environmental, psychosocial, and genetic factors. In some cases, medications, medical conditions, or genetic syndromes may also contribute (4). In fact, one of the most powerful drivers globally is poor nutrition. Over the past decades, food systems have changed significantly. Highly processed foods rich in refined carbohydrates, added sugars, and industrial seed oils are now widely available, heavily marketed, and often cheaper than fresh, nutrient-dense foods. In many low- and middle-income communities, including parts of South Africa, affordable whole foods are limited, while ultra-processed options are easy to access (11). Moreover, environmental factors add to the problem, including the lack of safe spaces for physical activity in many communities (12). At the same time, health systems frequently focus on treating complications rather than identifying and addressing weight gain early through prevention and routine monitoring (4). As a result, vulnerable and socioeconomically disadvantaged populations are disproportionately affected (13).
If we want to reverse the rising prevalence of obesity and its associated health risks, we must address the root causes, beginning with what people eat every day. Food choices matter, and so does nutrition knowledge. Improving health requires understanding which foods truly support the body and which contribute to disease (14). If nutrition is one of the main drivers of obesity, then it must also be part of the solution. Addressing obesity requires more than awareness. It requires practical action that improves food literacy, strengthens informed decision-making, and restores access to nourishing, whole foods.
At The Noakes Foundation, we believe that improving metabolic health begins with restoring real food to the centre of the plate. A Low Carbohydrate, High Fat (LCHF) real food approach focuses on reducing refined carbohydrates and added sugars, prioritising nutrient-dense whole foods, and supporting stable blood glucose and insulin levels. These metabolic factors play a key role in preventing and managing overweight and obesity. Through our community programme, Eat Better South Africa, we work directly within low and middle-income communities to make this knowledge practical, affordable, and sustainable. We provide education, skills, and ongoing support so that families can make lasting changes to their health. Our goal is not short-term dieting, but long-term metabolic health.
This year’s theme, “8 Billion Reasons to Act on Obesity”, reminds us that change must happen at every level. Systems need to improve. Policies must evolve. But meaningful progress also begins in homes, schools, and communities. By restoring access to real, nourishing food, we can help build healthier futures for generations to come.
Raja Pfisterer
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 that people can be empowered to take control of their health step by step, helping to build healthier communities and support long-term wellbeing.
References
(1) ECPO. (2026). World Obesity Day Europe. https://woday.eu/
(2) Wikipedia. (2026). World Obesity Day. https://en.wikipedia.org/wiki/World_Obesity_Day
(3) World Obesity Federation. (2026). 8 billion reasons to act on obesity. https://www.worldobesity.org/training-and-events/events/8-billion-reasons-to-act-on-obesity
(4) World Health Organization. (2025). Obesity and overweight. https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight
(5) Statistisches Bundesamt. (2026). Body-Mass-Index (BMI). https://www.destatis.de/DE/Themen/Gesellschaft-Umwelt/Gesundheit/Glossar/body-mass-index.html
(6) Ross, R., Neeland, I. J., Yamashita, S., et al. (2020). Waist circumference as a vital sign in clinical practice: A consensus statement from the IAS and ICCR working group on visceral obesity. Nature Reviews Endocrinology. https://doi.org/10.1038/s41574-019-0310-7
(7) Govender, I., & Sunnasy, A. (2025). The growing problem of obesity in South Africa. https://pmc.ncbi.nlm.nih.gov/articles/PMC11830878/
(8) World Obesity Federation. (2026). South Africa data. Global Obesity Observatory. https://data.worldobesity.org/country/south-africa-197/
(9) 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
(10) Simmonds, M., Llewellyn, A., Owen, C. G., & Woolacott, N. (2015). Predicting adult obesity from childhood obesity: A systematic review and meta-analysis. Obesity Reviews. https://doi.org/10.1111/obr.12334
(11) Reardon, T., Tschirley, D., Liverpool-Tasie, L. S. O., et al. (2021). The processed food revolution in African food systems and the double burden of malnutrition. Global Food Security, 28, 100466. https://doi.org/10.1016/j.gfs.2020.100466
(12) Sallis, J. F., Floyd, M. F., Rodríguez, D. A., & Saelens, B. E. (2012). Role of built environments in physical activity, obesity, and cardiovascular disease. Circulation. https://doi.org/10.1161/CIRCULATIONAHA.110.969022
(13) Wang, Y., & Beydoun, M. A. (2007). The obesity epidemic in the United States—Gender, age, socioeconomic, racial/ethnic, and geographic characteristics: A systematic review and meta-regression analysis. Epidemiologic Reviews. https://doi.org/10.1093/epirev/mxm007
(14) Gibbs, H. D., Stauber, C., & Knechtges, P. (2023). Nutrition literacy is associated with diet quality and obesity in adults: A systematic review. Journal of the Academy of Nutrition and Dietetics, 123(2), 235–248. https://doi.org/10.1016/j.jand.2022.10.011
