Body mass index, or BMI, uses a simple equation to measure the relationship of your height to your weight, www.PrimeBoosts.com telling you if you have a healthy level of body fat. For example, healthy adults with a lot of lean muscle mass, like bodybuilders and other muscular athletes, will likely have a BMI that lands them in the overweight category. You can't adjust the BMI equation to account for an athletic build. It simply relates your height to your weight Instead, rely on other methods, including waist circumference, to determine if you're at a healthy weight. These classifications apply to the general population, in which a heavier weight is likely due to higher levels of body fat, not muscle. A higher number on the scale in turn becomes a higher BMI, which can sometimes be associated with health risks. That's generally not the case with athletes who have a higher BMI because of muscle, not fat.