Ethnicity is now considered a contributing factor in the development of diabetes and obesity—two closely linked conditions driven by a mix of genetic, cultural and socioeconomic factors. Obesity increases the risk of type 2 diabetes because excess body fat, especially around the abdomen, causes insulin resistance and inflammation, making it harder for the body to control blood glucose. From genetic predispositions to cultural dietary habits and access to healthcare, different ethnic groups experience unique risks, outcomes and challenges when managing these conditions.
Historically, most clinical trials were conducted in high-income Western countries and were largely dominated by participants of white European origin. As a result, many biomarkers and treatment guidelines are based on these populations, limiting their applicability to other ethnic groups. Today, people from diverse ethnic, geographic, and socioeconomic backgrounds remain underrepresented in research.
By incorporating phenotypes, observable traits shaped by genes and environment, when assessing a person’s risk of developing diabetes, healthcare professionals can better understand the root causes, map progress and develop more effective treatments.
Ethnicity plays a significant role in the development of diabetes and obesity—two closely linked conditions driven by a mix of genetic, cultural and socioeconomic factors.
The global burden of diabetes and obesity is accelerating, with new data painting a worrying picture. The 11th edition of the IDF Diabetes Atlas estimates that 589 million people worldwide live with diabetes—a figure set to climb to 853 million by 2050. The steepest increases are expected in Africa and South-East Asia, with India and China driving much of the surge. Meanwhile, obesity continues its upward trend, affecting more than 1.9 billion adults globally. Yet these figures do not tell the whole story—these trends vary across regions and ethnicities.
So, is it ethnicity or where you live? While global trends show a modest increase in Europe, South-East Asia and Africa face exponential growth. India alone now presents over 101 million people with diabetes and more than 350 million with abdominal obesity. As diabetes rates rise, researchers have identified distinct phenotypes that offer us insight into how the condition develops and how it might be prevented or treated.
Historically, most clinical trials were conducted in high-income Western countries and have been dominated by participants of white European origin.
New research presented at the IDF World Diabetes Congress 2025 sheds fresh light on the striking regional disparities in diabetes risk and prevalence. Data presented during the session “How to explain ethnic differences in diabetes and obesity” revealed that populations in South-East Asia and Africa experience distinctive patterns of diabetes onset, driven by diverse populations and phenotypes.
In South-East Asia, diabetes often appears earlier and is more complex than in Western populations. Dr Ranjit Mohan Anjana, Madras Diabetes Research Foundation, India, presented a regional type 2 diabetes phenotype defined by early-onset, low-BMI cases, commonly seen in people aged 25 to 34. Despite appearing lean, many have increased visceral fat (dangerous fat stored around internal organs) and insulin resistance, a paradox referred to as “thin-fat”.
This form of diabetes is characterised by:
The root causes may even begin before birth. Despite similar birth weights, Indian newborns often present higher levels of visceral fat and hormonal imbalances than white European newborns.
Migration adds yet another layer to this complex picture. South Asians living abroad frequently show higher rates of diabetes than those who remain in the region. Dr Anjana pointed to lifestyle shifts post-migration as a key factor. However, she noted that rapid economic growth and urbanisation within India since the 1990s have also contributed to rising obesity and diabetes rates among those who never left.
South Asians living abroad frequently show higher rates of diabetes than those who remain in the region.
Moving eastward, the Western Pacific region, particularly China, has also become a global epicentre of the diabetes pandemic. The IDF Diabetes Atlas reports that 12% of Chinese adults have diabetes, with nearly 50% at high risk. Particularly concerning is the high rate of young-onset diabetes, with around 20% of people diagnosed before the age of 40. According to data from the Joint Asian Diabetes Evaluation Program (JADE), urbanisation, ultra-processed foods and sedentary lifestyles have contributed to this trend.
While South-East Asia presents a distinct early-onset profile, the Western Pacific presents a different, but equally concerning one. One of the more puzzling aspects is that many people develop the condition at what would be considered a healthy weight elsewhere. The underlying cause lies in physiology: these populations often produce less insulin and are more prone to visceral fat, even if their BMI looks reassuring on paper. These clinical features imply that even at a healthy weight, Asians have a lower beta cell function, which puts them at a higher risk of developing type 2 diabetes. Among adolescents who already experience hormonal insulin resistance, this can set the stage for a lifetime of chronic conditions.
Professor Ronald Ma, Chinese University of Hong Kong, emphasised genetic factors, especially the PAX4 gene, which plays a role in insulin-producing beta cells. Variants in this gene can increase diabetes risk by 80% in East Asian populations. Professor Ma called for better phenotyping and a shift toward mechanism-based risk assessment — an approach that evaluates genetics, insulin function and metabolism— rather than a general “high or low risk” label, and better phenotyping of people with young-onset diabetes.
In some Western Pacific populations, diabetes often develops earlier and at lower body weights—challenging assumptions about risk.
Africa’s diabetes story is equally complex—and often misunderstood. “Africa is not one country—it is a vast and diverse continent,” underlined Dr Eugene Sobngwi, Professor of Medicine and Chair of Endocrinology and Diabetes at the University of Yaoundé, Cameroon, pointing to a continent home to over a billion people in nearly 60 nations with hundreds of ethnic groups and health challenges. Furthermore, Sub-Saharan Africa is undergoing a protracted epidemiological transition, with rising chronic conditions like diabetes alongside persistent infectious diseases.
Estimates from the latest IDF Diabetes Atlas indicate that 25 million adults currently live with diabetes in Africa. This figure is expected to increase by 142% by 2050, bringing the total to 60 million adults—the highest percentage increase of any IDF Region. Alarmingly, 73% of adults with diabetes in Africa remain undiagnosed, representing the highest proportion globally.
Not only does diabetes prevalence vary among countries, but diabetes phenotypes also differ, with global definitions and classifications often falling short. Some people present with ketosis-prone type 2 diabetes, where ketoacidosis appears without the autoimmune markers typical of type 1 diabetes. Others develop diabetes linked to chronic undernutrition — recently classified as type 5 diabetes — or show signs of insulin resistance despite being lean.
In a study from Cameroon, women with abdominal obesity did not always have higher diabetes rates compared to men, suggesting that BMI alone is a poor indicator of risk in some African populations.
The interplay of infectious disease, malnutrition and rapid urbanisation in Africa creates distinct types of diabetes, which call for phenotypes tailored to African physiologies and environments. Healthcare systems can then counter diverse diabetes presentations through personalised approaches that improve diagnostic accuracy and rethink first-line treatments based on local pathophysiology (how diseases and conditions develop and affect the body).
The interplay of infectious disease, malnutrition and rapid urbanisation in Africa creates distinct types of diabetes, which call for phenotypes tailored to African physiologies and environments.
Undoubtedly, research indicates that genetics plays a role. South-East Asian populations, for instance, carry polygenic risk factors that influence beta-cell function. But genes alone cannot explain the sudden increase in diabetes over the past few decades. The globalisation of food systems, the rise in sedentary jobs and the erosion of traditional diets have all contributed.
In every region, the environment intersects with biology in complicated ways. Increasingly, the evidence shows that we need diabetes strategies that reflect that complexity. The growing consensus among researchers is that understanding these disparities favours the design of effective policies and interventions that are medically sound and culturally and regionally relevant.
Understanding these disparities favours the design of effective policies and interventions that are medically sound and culturally and regionally relevant.
So, what would that look like? First, public health campaigns need to be adapted culturally and regionally. Experts like Dr Anjana advise South-East Asians to reduce their carbohydrate intake and increase their protein intake, but only if such changes are achievable within local diets and food systems.
Encouraging physical activity is crucial for all populations, yet blanket advice often misses the mark. Walking may be viable in some neighbourhoods but impossible in others where infrastructure is lacking or personal safety is a concern.
Early screening is also key, but current diagnostic tools often fail to account for ethnic differences. Someone of South-East Asian descent may develop diabetes at a BMI that would not raise red flags in a Western clinic. Without revised guidelines, many at-risk individuals will remain undiagnosed until complications arise.
Only by understanding the intersection of ethnicity, environment, and physiology can we build health systems that prevent diabetes early and equitably across populations.
