Diabetes and Obesity: What’s the Connection?

By Lewis, Sarah, PharmD

What Is Obesity?

Healthcare professionals use your body mass index (BMI) to diagnose or define obesity. BMI is a ratio of your body weight to your height. If your BMI is 30 or more, you are considered obese. If your BMI is anywhere from 25 up to 30, you are overweight.

If you are obese, you’re at risk for developing type 2 diabetes. However, just because you’re obese doesn’t mean you will have diabetes and not all people with type 2 diabetes are obese. According to the American Diabetes Association, 15% of people with type 2 diabetes are normal weight and roughly 33% of obese people will never develop diabetes (Source: ADA).

How Does Obesity Lead to Diabetes?

Obesity increases your risk of developing insulin resistance. Your pancreas can still make insulin, but your cells can’t respond to it. This eventually leads to high blood sugar levels and causes your pancreas to make even more insulin. It turns into a cycle that ultimately causes your pancreas to burn out and stop making insulin altogether.The end result, type 2 diabetes, is a breakdown in your body’s ability to make insulin and process sugar.

Scientists have been studying how obesity and diabetes are related. Here are some findings:

  • They’ve found that carrying your body fat on your belly and trunk puts you at higher risk for insulin resistance and type 2 diabetes than carrying it other places. Think about apple and pear body shapes. If you have this type of round body shape, you tend to be higher risk.

  • They’re looking at how insulin resistance develops in obese people. They’ve found a possible link with certain hormones that your fat cells make. When you’re obese, your fat cells make more of these hormones. However, scientists don’t quite understand how these hormones cause insulin resistance.

  • They’re also studying why the cells in your pancreas stop working. They think that there could be a genetic factor in some people that makes it more likely for pancreas cells to shut down.

  • They’ve seen that bypass weight-loss surgery produces unique effects on diabetes that gastric banding weight-loss surgery does not. They’ve also noticed that the longer you’ve had diabetes, the less likely you are to see improvements in your diabetes after weight-loss surgery.

  • They’ve found certain brain cells that normally react to high blood sugar and try to signal your body to return blood sugar levels to normal. When these brain cells are defective, they don’t send the normal signals. Studies on animals show that this defect increases the risk of obesity-related diabetes.

  • They’re looking for a specific gene or genes to link diabetes and obesity.

The research behind obesity and diabetes is complicated and scientists are still developing ways to understand the connection. For now, it’s important for you to know that there is a strong link between obesity and type 2 diabetes. And remember, if you can achieve and maintain a healthy body weight, you may be able to prevent or even reverse type 2 diabetes.

Risk Factors for Type 2 Diabetes

While the connection between diabetes and obesity is strong, it isn’t absolute. This may make you wonder what other factors put you at risk for type 2 diabetes. Health experts don’t know exactly what causes diabetes, but they do know that certain factors increase your risk. They include:

  • Being overweight or obese

  • Having a family history of type 2 diabetes

  • Not exercising regularly

  • Aging

  • Having a personal history of gestational diabetes

  • Belonging to certain racial or ethnic groups, including African Americans, Asian Americans, Hispanic Americans, Native Americans, and Pacific Islanders

Medical Reviewer: McDonough, Brian, MD Last Annual Review Date: 2011-11-02T00:00:00-06:00 Copyright: © Copyright 2011 Health Grades, Inc. All rights reserved. May not be reproduced or reprinted without permission from Health Grades, Inc. Use of this information is governed by the HealthGrades User Agreement.

Your Guide to Diabetes


Diabetes Video Guide