The Link Between Diabetes and Obesity: The Reality of “Diabesity”

Today, diabetes and obesity are among the leading global health problems and are frequently seen together. The relationship between these two conditions is so strong that the term “diabesity” (diabetes + obesity) is widely used in scientific literature. So, how does diabetes lead to obesity? Does every obese individual have diabetes? In this article, we explore the answers to these questions based on scientific evidences.

How Does Obesity Increase the Risk of Diabetes?

As Type 2 diabetes develops, the risk of obesity increases, and likewise, obesity is one of the most important risk factors for developing diabetes. Research shows that approximately 80% of individuals with Type 2 diabetes are obese.

The main reason lies in the negative effects of excess fat tissue on metabolism. As body fat increases, the effectiveness of insulin decreases. Reduced insulin function disrupts blood sugar control, altering metabolic balance. These processes are interconnected and work like a chain, ultimately creating a favorable environment for the development of diabetes.

The Core Mechanism: Insulin Resistance

Under normal conditions, insulin allows glucose in the bloodstream to enter cells. However, in obese individuals, cells respond less effectively to insulin. As a result, the pancreas is forced to work harder and produce more insulin. In response to elevated insulin levels, cells begin to protect themselves, leading to insulin resistance.

Additionally, free fatty acids and hormones released from fat tissue further increase insulin resistance. This disruption causes blood sugar levels to rise.

This process forms the foundation of Type 2 diabetes. Diets high in sugar and fat, commonly seen in obesity, play a key role in building this foundation. The most critical link between obesity and diabetes begins with insulin resistance.

Three Key Mechanisms Explaining the Obesity–Diabetes Link

According to NCBI sources, there are three main biological mechanisms that explain the relationship between obesity and diabetes: chronic inflammation, lipid overflow, and adipokine imbalance.

1. Chronic Inflammation (Inflammation Hypothesis)
Inflammation is actually a natural healing response of the immune system. It occurs when the body activates its defense mechanisms against harmful stimuli such as infections, injuries, or toxins. However, obesity causes a state of low-grade chronic inflammation in the body. Immune cells accumulated in fat tissue produce inflammatory cytokines, disrupt insulin signaling, and increase the risk of diabetes.

2. Lipid Overflow (Lipotoxicity)
When fat tissue exceeds its storage capacity, excess fat begins to accumulate in organs such as the liver, muscles, and pancreas. This process damages cells and leads to insulin resistance.

3. Adipokine Imbalance
Adipokines are signaling proteins secreted by fat tissue that regulate appetite, energy balance, metabolism, insulin sensitivity, and inflammation. In obesity, hormones such as leptin and adiponectin become imbalanced. This disrupts metabolic balance and reduces insulin sensitivity.

Body Fat Matters

Not all fat is the same. Visceral fat, particularly around the abdomen, significantly increases the risk of diabetes. This type of fat surrounds internal organs, promotes inflammation, and accelerates insulin resistance. Interestingly, even individuals with normal weight but high levels of internal fat (TOFI – “thin outside, fat inside”) can carry a risk for diabetes. However, the risk is generally higher in obese individuals due to increased visceral fat.

Does Every Obese Individual Develop Diabetes?

No. Each individual has a unique biological makeup. While obesity is a strong risk factor, it is not sufficient on its own. In some individuals, the pancreas can compensate for insulin resistance. The development of diabetes also depends on genetic predisposition, lifestyle, and the function of pancreatic beta cells.

The Relationship Between Weight Gain and Diabetes Risk

Scientific data show that as body mass index (BMI) increases, the risk of diabetes rises dramatically. The risk can increase from 7% to 70% in men and from 12% to 74% in women. This clearly demonstrates the powerful impact of obesity on diabetes risk.

Good News: The Risk Can Be Reduced

Although the link between obesity and diabetes is strong, it is also reversible. Even a 5–10% weight loss can significantly reduce the risk of diabetes. Physical activity improves insulin sensitivity, while healthy nutrition enhances metabolic function. These lifestyle changes can even slow down the progression of diabetes.

Conclusion: The Obesity–Diabetes Connection

The relationship between obesity and diabetes is not only statistical but also biologically strong and multifaceted.

Obesity → inflammation + hormonal imbalance + lipid overflow
This process → insulin resistance
Result → Type 2 diabetes

However, this process is not inevitable. With early intervention, lifestyle changes, and proper treatment, both obesity and diabetes can be effectively managed.

References

NCBI Bookshelf – Molecular Links Between Obesity and Diabetes (“Diabesity”)
Kahn SE et al., Nature – Mechanisms Linking Obesity to Insulin Resistance
CDC – Insulin Resistance and Type 2 Diabetes
StatPearls (NCBI) – Obesity and Type 2 Diabete