Obesity Itself Not a Type 2 Diabetes Risk Factor

The link between obesity and Type 2 diabetes is well established in most people’s minds, but it is excess visceral fat (fat that surrounds the internal organs) and insulin resistance — not obesity in and of itself — that puts people at increased risk for Type 2, according to new research published in The Journal of the American Medical Association.


Noting that obese people have varying levels of risk for developing prediabetes and Type 2 diabetes — millions of overweight and obese people do not develop either of these conditions — researchers from the University of Texas Southwestern Medical Center evaluated 732 obese individuals to determine specifically what factors might increase diabetes risk in this population.

Participants all had a body-mass index of 30 or greater, were between ages 30 and 65, and did not have diabetes or cardiovascular disease when they were enrolled in the Dallas Heart Study from 2000 to 2002. Information about a variety of factors was collected, including their family history of diabetes, body surface area, waist circumference, visceral and subcutaneous (under the skin) abdominal fat levels, liver fat, fasting blood glucose, levels of various biomarkers of insulin resistance, and cholesterol levels.

At a follow-up of seven years, 84 of the 732 participants had developed Type 2 diabetes. Having increased markers of insulin resistance, elevated fructosamine (a measurement indicating average plasma glucose level over several weeks), elevated fasting glucose, a family history of diabetes, increased systolic (the top number) blood pressure, weight gain over the follow-up period, and excess levels of visceral fat were all associated with an increased risk of developing Type 2 diabetes; excess visceral fat was linked with a more than twofold increase in the risk. General measures of obesity, however, such as body-mass index, total body fat, or subcutaneous abdominal fat were not associated with an increased risk of developing Type 2.

Roughly 39% of the 512 participants who’d had normal fasting glucose levels at the start of the study developed prediabetes, which was associated with elevated levels of visceral fat, fructosamine, and insulin; older age; non-white race; family history of diabetes; and weight gain over follow-up. Again, developing the condition was not associated with obesity itself.

“Our study may have implications for understanding differences between metabolically healthy and [unhealthy] obesity,” the study authors note.

According to lead study author James de Lemos, MD, the only way to determine whether fat is visceral or subcutaneous is with an imaging study such as magnetic resonance imaging (MRI).

For more information, read the article “Obesity Itself Not Diabetes Risk” or see the study’s abstract in The Journal of the American Medical Association. And to learn more about visceral fat, read the threepart series “Blasted Belly Fat,” by diabetes dietitian Amy Campbell.

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  • jim snell

    my goodness. Finally some rational comments about this.

    All that obesity flags is that the body in question has excess glucose from liver/diet left over in veins and arteries and said body is capable of storing that liquid energy as fat.

    Thin Type 2’s and obese type 2’s have one common factor – the glucose level in their blood is constantly too high causing rot out of the body – Type 2.

    The role of energy balance, glucose saturation in type 2 skeletal muscle temporary glucose sites being full all the time, as well as the inability of the hunter gatherer gene/digestion system from being unable to stop shoving more glucose into the blood system and have some ability to throw over the side/bypass the excess glucose produced when body is obviously topped off are key issues being ignored in current type 2 diabetes and finding best ways to stop the problem.

    The thought that excess and constant extra glucose can be thrown against the human blood system and processes and cell storage that burn that off continuously without long term impact is countered by the large increases of type 2 diabetes. Unless I am mistaken or misinformed, this explosion co-insides with the huge gains in development, production and higher grades of grain, corn and rice to stave off world wide starvation.

    Couple that with major gains in computers, and semiconductor technology, cars and labour saving devices that have dropped the exercise and energy burn, massive amounts of liquid energy are backing up in our bodies which for me has led to this massive increase in type 2 diabetes.

    I also tend to agree that chemicals, genetic lashups, auto-immunie diseases can lead to extra medical conditions that further acerbate the problem.

  • Russell

    I have researched some about this deadly disease especially after my sister was hit with type 2. But I am learning more about it and this information is good to know. Before, when I knew nothing about diabetes I remember hearing in general, talk about obesity putting people at risk of developing diabetes. I think as we progress forward and learn more it will start to break people’s thinking away from that old mentality and help all of us to realize what is true and what is myth.

  • Jason

    Glad that someone has finally decided to deem that weight is not related to diabetes at all times. My doctor has told me that losing weight will help control my type 2 diabetes. I have lost over 30 lbs, they have deemed that I need to lose more weight. Want to have me take metformin also. Have tried to this once, but it pushed my glucose levels to low. What other choices have others used.

  • sue

    Do not forget to factor in lack of sleep – it may tire out the enzyme patterns.

  • Roger

    As a person who has been obese and now 72 lbs lighter, and going to the gym six days a week, I have seen my type 2 going from an A1C of over 8.5 down to 5.1 for three years in a row. ALL of my diabetic classes offered nothing to train me to correctly grasp and control the processes at work helping to cause my insulin resistance. I had to enroll in a cardiovascular program to successfully reverse my glycemic syndrome and return my heart to a very healthy organ..measured by every available test. wishful thinking is no substitute for knowledge and subsequent action to live a more active and healthy lifestyle. ANYTHING that promotes escuses for eating unhealthy types and quantities of food, is just plain wrong and deadly. While it is true that “belly fat” is the majot contributor to type 2 diabetes, I find it rare that one can be obese and NOT have belly fat. There is just so much misinformation and folklore surrounding insulin resistant diabetes, you have to seriously question if the United Staats has not fallen into a third world mentality of backward thinking and false treatment for many diseases including diabetes and coronary artery disease. Elevated blood glucose levels cause INFLAMMATION, and that roughens arterial walls… triggering the release dangerous proinflammatory cytokines that are mainly responsible for artherosclerosis/ plaque buildup. Most Americans have absolutely no idea how their choices of foods and (lack of) excercise contribute significantly to their mortality rate..but once they do, they will be irate, knowing just how senseless and easily changed this situation could be.