Obesity and Diabetes

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As the prevalence rates of obesity have skyrocketed in the United States and across the world, so have the rates of Type 2 diabetes. In 2010, it was estimated that 26 million people in the U.S. had a diagnosis of Type 2 diabetes, and 79 million had pre-diabetes. In addition, estimates indicate that many more may have Type 2 diabetes and not know it yet. According to the Centers for Disease Control and Prevention (CDC), if the current trends continue, as many as 1 in 3 people in the U.S. could have diabetes by the year 2050.

What Is Type 2 Diabetes?

Diabetes mellitus is the medical term for the disease in which the human pancreas is unable to make enough insulin. Without enough insulin, the body is unable to process glucose (a necessary sugar for humans that serves as the primary energy source for vital organs, including the brain) adequately, if at all. Because sugar is not being used by body organs, it accumulates in the bloodstream, and thus the hallmark of diabetes is hyperglycemia, or high blood sugar.

As opposed to Type 1 diabetes, in which affected individuals are usually born with a genetic deficiency of adequate insulin production, the majority of Type 2 diabetes cases are triggered by lifestyle factors that are preventable, such as obesity. To be sure, these environmental factors interact against a genetic backdrop that can predispose a person to be more likely to develop Type 2 diabetes. Individuals with such a genetic predisposition are thus considered to be at risk for Type 2 diabetes at baseline.

Factors that indicate someone may have a genetic predisposition to developing diabetes include a family history of diabetes (i.e., having a first-degree relative with diabetes) and race/ethnicity (African Americans, Arabs, Latinos, Native Americans, Asian Americans, Pacific Islanders and South Asians have greater genetic predisposition to developing diabetes).

Why Is Diabetes a Problem?

As noted above, untreated diabetes results in high blood sugar levels, which then cause direct and indirect damage to multiple body systems, including the circulatory system, the nervous system, the renal and urinary system, and many others. Thus, diabetes is a leading cause of blindness and kidney failure (which often results in needing dialysis) in the United States. Diabetes also highly increases the risk for cardiovascular disease in the form of heart attacks and strokes as well as disease throughout the vascular system.

Diabetes also results in immunosuppression, which means that the body’s immune system is less equipped to respond to infection and inflammation. This is why patients with diabetes may experience delayed wound healing—and why diabetes is also a leading cause of lower limb amputations.

How Does Obesity Result in Diabetes?

The concept of insulin resistance, in which body organs become resistant to the effects of the insulin that the pancreas does produce, is a very important one in understanding the process that leads to full-blown Type 2 diabetes.

Obesity causes insulin resistance, which over time leads to pre-diabetes and then Type 2 diabetes, as the pancreas burns out and simply cannot make any more insulin for a resistant body that has essentially “used up” its insulin stores and production ability. The metabolic demands of obesity put great stress on the pancreas, which can lead to Type 2 diabetes.

How Can Diabetes Be Prevented?

Large studies have shown that regular exercise and weight loss of just 5-10% of body weight can reduce the risk of diabetes by nearly 60%. Maintaining a normal weight and keeping physically active can reduce risk even further. Keeping sugar intake in check, as well as intake of highly refined carbohydrates, is also important for reducing diabetes risk. In addition, just as getting enough sleep on a regular basis is important for preventing obesity, so too does it reduce the risk of developing diabetes.


Seaquist ER. Addressing the burden of diabetes. JAMA 2014; 311:2267-68.

American Diabetes Association. Standards of medical care in diabetes—2014. Accessed online at http://care.diabetesjournals.org/content/37/Supplement_1/S14.full.pdf+html on June 19, 2014.

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