Why does BMI not always work?

Answer 1

BMI can be inaccurate in some cases, because people with a lot of muscle mass will be classified as "overweight" or "obese" according to BMI, when in reality, they're actually not at all. Muscle is more compact and a lot more dense than fat is, so a 250-pound bodybuilder will obviously look (and be) healthier than a 250-pound sedentary guy.

Answer 2

BMI isn't always accurate because some people have more muscles than others. Muscle is more dense than fat, and BMI doesn't take that into account. For example, let's say we have two guys. They're both 5'11, and they both weigh 280 pounds. One is a bodybuilder - he has a lot of muscle mass, and very little fat. The other, however, never exercises and is made up of mainly fat. According to their BMIs, they're both considered obese, but which one do you think is healthier? Obviously the one with mostly muscle. That's why it's a great guideline in some cases, but most of the time, it's a far more accurate health indicator to get a body fat test done instead.

Answer 3

It simply caluculates your weight and height rather than how much of that is muscle and good fat.

Answer 4

Because it actually depends on what kind it talks about!

Answer 5

Because Jorge Barrahona invented it.