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.

The unequal rising prevalence of diabetes

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.

Regional differences and ethnic phenotypes

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.

South-East Asia: early onset and the “thin-fat” paradox

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:

• Rapid beta-cell decline following early hyperinsulinemia
• Abnormal lipid profiles (low HDL, high triglycerides)
• Chronic inflammation and low adiponectin
• Gut microbiome imbalances and vitamin D/B12 deficiencies
• Increased risk of cardiovascular and microvascular complications

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.

China and Western Pacific: younger, thinner—and still at risk

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.

Africa: a mosaic of metabolic realities

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).

Nature, nurture and everything in between

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.

Towards better diagnosis and more equitable care

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.

At first, the International Diabetes Federation South and Central America (SACA) region can appear homogenous, with cultural, linguistic and historical similarities. However, unique geographical, economic and population characteristics distinguish the 19 countries in the IDF SACA region. The diabetes landscape in South and Central America is characterised by an increase in diagnosis, financial burden and public health challenges.

Facts and figures from SACA

Although the region is not one of the most at risk for diabetes, estimates released by the IDF in 2021 show that approximately 33 million adults live with some form of diabetes in the region, with a further 11 million – 1 in 3 – living undiagnosed.  Moreover, 80% of patients with type 2 diabetes in the region experience diabetes-related complications, including the most common ones: cardiovascular diseases (CVD), chronic kidney disease (CKD), and neuropathy.

While type 2 diabetes is more prevalent in the SACA region, 121,000 children and adolescents live with type 1 diabetes, with about 9,500 new cases diagnosed annually in this age group.

Common challenges for people with all types of diabetes include access to insulin and supplies, and navigating healthcare systems, where a shortage of trained healthcare professionals can impede effective diabetes management.

The value of UHC, early screening and prevention

In a region that experiences high levels of income disparity, the economic impact of the diabetes burden costs around USD 70 billion annually, forming a significant part of national health budgets. Only a few countries — Chile, Costa Rica, and Colombia — have universal health coverage for people with diabetes, while Argentina, Brazil, Guatemala, Peru, and Uruguay provide a high portion of coverage.

Some countries have incorporated national screening programmes to identify risk factors, resulting in more people being diagnosed with diabetes. When diabetes — whether type 1 or type 2— is diagnosed early, trained healthcare professionals can collaborate with their patients to set up a diabetes management plan to delay or prevent complications and maintain overall well-being.

Like other regions, the prevalence of diabetes, especially type 2 diabetes, is primarily driven by urbanisation, dietary changes and sedentary lifestyles. The last determining factor is the most alarming. Globally, 11.2 million new cases of diabetes due to physical inactivity are predicted between 2020 and 2030. In contrast, in rural settings, outside of metropoles and large cities, the prevalence is much lower, partly due to more physical activity and limited access to processed foods.

Brazil leading the diabetes burden

Diabetes has become a major public health issue in Brazil due to its increasing prevalence caused by lifestyle changes, ageing populations and rising obesity rates. The region’s largest and most populated country, Brazil accounts for just under half—15 million—of the region’s people with diabetes and ranks sixth globally. In the SACA region, the prevalence of type 2 diabetes is the highest in Brazil.

The public healthcare system, Sistema Único de Saúde (SUS), provides free treatment, including insulin and medications. Despite this, access to specialised care is not always straightforward, especially in rural areas. Diabetes complications like cardiovascular disease, kidney failure and limb amputations are common and add to the already overstretched healthcare system. Government initiatives focus on prevention, awareness and diabetes screening for early diagnosis. Still, socioeconomic inequalities make it challenging to reach all affected populations.

The uptake of technology

The increasing prevalence of diabetes and the need for effective diabetes management drive the uptake of diabetes technology in South and Central America. Though adoption rates vary across the region, continuous Glucose Monitoring (CGM) systems, insulin delivery devices, and digital management tools are increasingly used in diabetes management.

Ronaldo Wieselberg, an IDF diabetes advocate from Brazil, remembers all the changes in treatment that have occurred since he was diagnosed with type 1 diabetes at the age of two. In 1993, diabetes treatment was vastly different from what it is now. Multiple insulin dose therapy was new and not commonly prescribed, and technology to deliver insulin and monitor blood glucose levels was much less technologically advanced.

Nonetheless, the prohibitive cost of diabetes devices and varying levels of healthcare training hinder widespread adoption, particularly in countries with limited healthcare funding.

At-risk populations

According to a study published in 2014, Indigenous people account for more than 5% of the total population in Honduras, Nicaragua, Panama, Ecuador and Peru, and more than 40% in Guatemala and Bolivia. Although Indigenous Populations are the region’s first inhabitants, they were previously underrepresented in many aspects of diabetes research.

The risk of developing diabetes and diabetes-related complications increases when lifestyle changes occur. For example, the Mapuches and Aymaras in Chile living in rural areas had the lowest rates of type 2 diabetes worldwide, at less than 1%. However, this increased to 8.2% and 6.9%, respectively, in those who moved from rural to urban environments.

Rural Indigenous populations have traditionally used local plant leaves, cacti, and tree bark to help regulate blood sugar levels. Healthy nutrition also contributes to diabetes prevention in rural communities, where whole, unprocessed foods, including beans, corn, quinoa, and other high-fibre foods, are common and help regulate blood sugar. Traditional fasting practices and meal timing may also influence glucose control. Physical activity — walking long distances, farming, and traditional dance — is a natural part of daily life in many communities and helps prevent obesity and diabetes.

Given these traditional lifestyles, tailoring diabetes prevention programmes to respect and incorporate local cultures and traditions can enhance their effectiveness and acceptance.

A second at-risk population is people of African descent, who experience higher rates of diabetes. In the region, 134 million people identify as Afro-descendants. While specific data on diabetes prevalence among Afro-descendants in SACA are limited, studies from related regions provide insights. Their findings suggest that people of African descent may have a higher predisposition to diabetes, possibly due to genetic factors, lifestyle and environmental influences. These communities often encounter starkly unequal social and economic conditions that adversely affect their health outcomes.

Genetics make Afro-descendants susceptible to sickle cell disease, an inherited red blood cell disorder in which red blood cells are crescent or “sickle” shaped and do not bend or flow easily. These sickle-shaped cells block blood flow to the rest of the body and cause repeated infections and sporadic painful episodes.

Some A1C testing methods for blood glucose may produce unreliable results for people with the sickle cell gene. Falsely high outcomes can lead to the prescription of more aggressive treatments, resulting in increased episodes of hypoglycaemia. Conversely, falsely low outcomes can lead to the undertreatment of diabetes.

Linking sugary drinks to the rise of diabetes

Among some of the highest consumers of sugar-sweetened beverages (SSBs) in the world, the SACA region has seen a rise in obesity and diabetes, contributing to almost a quarter (24%) of new type 2 diabetes diagnoses in 2020. The prevalence of diabetes and obesity in South America is closely linked to dietary habits, particularly the consumption of sugary drinks. The highest impact is in Colombia, where sugary drinks are responsible for almost half (48%) of all new diabetes diagnoses. Additionally, healthcare costs associated with diabetes and CVD, both linked to SSB consumption, amount to billions of dollars annually.

In response, several countries in the region have implemented measures such as taxation on sugary drinks, marketing regulations and public health campaigns. For example, Chile implemented comprehensive regulations, including front-of-package warning labels and marketing restrictions, resulting in decreased SSB consumption.

Campaigning for early diagnosis

Many people with diabetes in the region live undiagnosed. Estimates suggest that around 32% of adults with diabetes are unaware of their condition in the absence of screening. Early diagnosis and intervention underpin effective diabetes management, leading to timely treatment and reducing the risk of diabetes complications and strained healthcare systems.

Diabetes research in the SACA region has largely contributed to understanding these challenges and developing targeted interventions. The region also relies heavily on the 37 IDF Member organisations to lead public diabetes awareness and advocacy. In 2023 alone, 22 Member Associations carried out 360 activities and initiatives ranging from prevention campaigns to diabetes education for healthcare professionals to community support programmes for diabetes management and mental well-being.

As the diabetes epidemic grows, we need to adapt strategies and lifestyle interventions to match changing and diverse populations. Concerted advocacy efforts in prevention, management, and access to healthcare can improve outcomes for people living with diabetes.

Type 1, type 2 and gestational diabetes are the most well-known and commonly diagnosed forms of diabetes, but other rarer types of diabetes exist.

Approximately 1.5-2% of people with diabetes live with rare forms of the condition, which can fall into nine categories. These less common types of diabetes may not receive as much attention as the more prevalent forms. However, they still pose a significant health threat to those affected by them.

Rare forms of diabetes require specialised treatment and management, often involving genetic testing and personalised approaches to insulin therapy. Of these rare forms of diabetes, LADA, MODY and neonatal diabetes are the most diagnosed. Raising awareness and diabetes education are particularly important so healthcare professionals can provide accurate diagnoses and appropriate care.

Latent Autoimmune Diabetes in Adults (LADA)

LADA, or Latent Autoimmune Diabetes in Adults, develops when antibodies damage insulin-producing beta cells in the pancreas.

While LADA — sometimes called type 1.5 diabetes — shares certain similarities with type 1 diabetes, such as the destruction of beta cells and the need for insulin therapy, its onset and progression differ. Unlike type 1 diabetes, which typically develops in childhood or adolescence, LADA usually develops in adulthood.

Additionally, LADA progresses at a slower pace than type 1 diabetes. Initially, the pancreas can produce some insulin before insulin treatment becomes necessary. This slower progression can sometimes lead to misdiagnosis or delayed diagnosis. LADA is often initially mistaken for type 2 diabetes.

Monogenic diabetes

As the name suggests, monogenic diabetes is the mutation or alteration of a single gene. It accounts for roughly 1-4% of all diabetes and is characterised by the pancreas’s inability to produce enough insulin. Two common forms of monogenic diabetes are MODY (Maturity-Onset Diabetes of the Young) and neonatal diabetes. Differing from LADA and type 1 diabetes, MODY is usually diagnosed before the age of 25. It is frequently found in multiple generations within a family. Genetic testing is often necessary to confirm a diagnosis of MODY and identify the specific gene mutation involved.

The gene mutations associated with MODY determine the severity of the condition. Likewise, the onset age can be valuable in developing a treatment plan and reducing the risk of diabetes-related complications.

Neonatal diabetes usually appears within the first six months of life and can have genetic and non-genetic causes. In some cases, neonatal diabetes results from gene mutations that disrupt the normal functioning of the pancreas, impacting insulin production and blood glucose levels. Neonatal diabetes can also occur because of non-genetic factors such as infections or complications during pregnancy. Early diagnosis and treatment are crucial for managing neonatal diabetes and ensuring optimal growth and development in infants affected.

For some people with MODY and infants with NDM, sulfonylurea, an oral diabetes medication that stimulates insulin production in the pancreas, can be used to manage their condition. Others may require insulin injections.

Double diabetes: a dual challenge

Double diabetes occurs when a person with type 1 diabetes develops insulin resistance, a characteristic feature of type 2 diabetes. Type 1 diabetes is constant in these cases, but it is possible to moderate the effects of insulin resistance.

If not properly managed, double diabetes can progressively worsen. Regular insulin treatment is required, and lifestyle interventions are crucial to managing insulin resistance.

The importance of personalised treatment plans

Understanding the unique characteristics of different forms of diabetes is crucial for appropriate diagnosis, treatment, and management. While these forms of diabetes may be less common, they highlight the condition’s complexity and diversity. Furthermore, they underscore the importance of personalised treatment plans and lifestyle modifications in managing diabetes effectively.

As with type 1 and type 2 diabetes, rarer forms of diabetes can also increase the risk of diabetes complications such as heart disease, stroke, and kidney disease. Good blood glucose management and maintaining a healthy body weight are important to reduce the risk of diabetes complications.

A call for awareness and education

LADA, monogenic and double diabetes represent important challenges to diabetes management. However, advancements in genetic testing and a deeper understanding of these conditions allow for more accurate diagnoses and effective treatment strategies. Raising awareness about these less common forms of diabetes is an essential step towards better healthcare outcomes. Healthcare professionals and people affected must understand the complexities of diabetes for appropriate diagnosis and treatment. Diabetes educators play a pivotal role by providing accurate information and promoting self-management strategies to ensure positive health outcomes for people diagnosed with rare and more prevalent types of diabetes.

By understanding the diverse nature of diabetes, we can work towards a future where everyone receives the personalised care they need, leading to healthier lives for all.