Heart Attack, Type 2 Diabetes, & Your BMI

If you are trying to lose weight, you've probably heard of the body mass index, or BMI. Developed in the 1830s, this calculation was once considered the gold standard for determining a body's healthiest weight range. Now, however, the BMI is hotly contested, with many people, including medical professionals, calling it an inefficient system to gauge one's size.

But can BMI be used to gauge other risks? A new study published in JAMA Internal Medicine sought to find out.

Seeing (and Studying) Double

For this study, researchers at the Umeå University in Sweden analyzed over 4,000 sets of identical twins. The subjects, who ranged in age between 42 and 92, had identical DNA but different levels of body fat – and therefore different BMIs. The team conducted their research from 1998 to 2003, with an additional follow up in 2013.

What did they find?According to lead researcher Peter Nordström, Ph.D., “The fatter twin actually had a lower risk of myocardial infarction (heart attack) or death, although the risk of diabetes was higher.”

Breakdown by BMI

Let's look at Umeå University's findings by the numbers:

• Among the twins with a higher BMI, there were a total of 203 heart attacks and 550 deaths between 2003 and 2013.
• For the twins whose BMI were lower, heart attacks and deaths tallied in at 209 and 633, respectively.

Dr. Nordström explained that these findings reveal that “obesity does not seem to be associated with cardiovascular disease or death, at least not to an increased risk.” However, the team did note that the heavier twin was at an increased risk for the onset of type two diabetes – about twice as likely.

“What the study does show is that there's a strong association between obesity and diabetes,” the team wrote in a press release, “which leads us to conclude that weight reduction interventions can be more effective against diabetes than when it comes to reducing the risk of heart attack and mortality.”