At first this question may seem to have an obvious answer. But looking at the data actually tells a more interesting story. We know the most from a large collection of data collected by the US government called the NHANES (National Health and Nutrition Examination Survey) data sets. For more information see the NHANES Web Site. The most important question is, "Does being overweight shorten your life expectancy?" To answer this question we need to define what being overweight is first. While there is much debate about the best way to do this, the simplest and for all practical purposes, most accurate way is to calculate your body mass index or BMI. A quick way to do this is to use the BMI calculator at the CDC web site. Overweight is defined as having a BMI between 25 and 30, obese as having a BMI between 30 and 40 and morbidly obese as having a BMI above 40.

The first surprise is that being overweight does not shorten your lifespan. However being obese does and being morbidly obese can shorten it by over a decade of life. If you are just overweight don't get too excited however. While your life span is not shortened, you are much more likely to have many disease including diabetes, heart disease, cancers and Alzheimer's disease. To see just how much of an increased risk you might be at for several disease check out the links below.