Does Obesity Cause Diabetes—or Vice Versa?

It may be hard to see whether diabetes or obesity comes first.

Loading the player...

Research suggests that obese people are three times more likely to develop type 2 diabetes compared to individuals who are at a “normal weight.” The question is, does one cause the other? Which comes first: obesity or type 2 diabetes?

What is Excess Weight or Obesity?

Obesity refers to a body mass index, or BMI, of 30 or higher. BMI is a way of measuring weight by comparing it to your height. Usually, a high BMI means you have extra body fat, but it could also be high due to muscle mass or bone mass. Learn more about how doctors define obesity here.

BMI isn’t a perfect measure of someone’s health. However, obesity statistically increases a person’s risk of having:

  • High blood pressure
  • High cholesterol
  • Heart disease
  • Type 2 diabetes
  • Certain types of cancer
  • Osteoarthritis (due to strain on the joints)
  • Stroke

What is Type 2 Diabetes?

Type 2 diabetes is a long-term medical condition that can be debilitating or even life-threatening. It develops when the body stops using insulin appropriately. (This is different than type 1 diabetes, where the body doesn’t produce its own insulin at all.) Learn more about the difference between type 1 and type 2 diabetes here.

Insulin is a hormone produced by the pancreas that helps the body use blood glucose for energy. If your body is not producing or using insulin appropriately, that glucose stays in the blood stream. This can cause high blood sugar levels, among other things. Type 2 diabetes requires daily monitoring of a your blood sugar level to help prevent high and low blood sugar, which can be dangerous.

Diabetes and Obesity: What Comes First?

You probably know by now that obesity increases your risk of type 2 diabetes. One reason for this is that belly fat produces substances that cause chronic inflammation. This inflammation may increase the risk of many health problems, including type 2 diabetes.

However, type 2 diabetes also increases your risk of obesity. Having insulin resistance and high blood sugar levels appears to cause weight gain, or make it harder to lose weight. As a result, type 2 diabetes can propel obesity, and vice versa.

How Treating Obesity Will Treat Type 2 Diabetes

Weight loss is an important tool for people who have obesity and type 2 diabetes. Moderate and sustained weight loss can lead to improved insulin sensitivity. This means your insulin is better able to clear out glucose from your bloodstream, so you have better blood sugar control.

A combination of diet, exercise, and behavior changes can help treat obesity, which in turn can help you manage your type 2 diabetes. Similarly, treating your type 2 diabetes and achieving good blood sugar control could make weight loss easier. Learn more about treating type 2 diabetes here.

If you have problems managing your diabetes or obesity, talk to your primary care physician or endocrinologist so you can come up with ways to make treatment and daily living easier.