Researchers at Centers for Disease Control and Prevention use body mass index, or BMI, which is essentially weight divided by height squared, to define weight categories. They define obesity as a BMI of 30 and above, overweight from 25 up to 30 and normal weight as 18.5 to 25. They found that obesity was linked to about eleven percent of deaths from a number of cancers, and obesity was associated with about nine percent of cardiovascular deaths. But overweight had no association with those deaths.
About 40 % of deaths in the U.S. population are due to causes that are neither cancer nor cardiovascular disease, and the researchers found that overweight was associated with a significantly reduced number of deaths from those causes. It is important to note that a person who falls under the “overweight” category may show no visible signs of carrying extra weight.
To calculate your BMI, log onto www.cdc.gov/nccdphp/dnpa/bmi.