Is a bmi accurate?

How do you know that BMI's are accurate? It doesn't take into consideration your other elements that could make you overweight. There are a ton of possibilities...so how do we know it's right? There are a lot of factors that it doesn't evaluate, like...

bone structure and health problems you already have. It could be genetics, muscle [because muscle does weigh more than fat] and lots of other things.

All that you're saying is true, and a reputable doctor would never use a person's BMI to diagnose whether or not they were over or underweight. Originally, the BMI was used as a statisitcal measurement, not as a diagnostic tool.

However, the BMI can be a good jumping-off point. It gives a more accurate representation of whether a person is over or underweight than simply looking at the number on the scale.

So it's accurate in that as a statistic, it tells you where you fall on the population graph. The BMI is only as accurate as what you want to use it for.

That is true, however like mikeh said it is a jumping off point. If you're severely underweight or overweight on the bmi chart then odds are there's something wrong...

Essentially, BMI is a simple mathematical formula, based on height and weight, that is used to measure fatness. You should be aware of your BMI because of the health risks of being overweight (that is, having a BMI of 25 or over). According to a report in the August 2006 New England Journal of Medicine, excess body weight during midlife is associated with an increased risk of death.

On the other hand, being too thin and having a BMI that's below the healthy range (18.5 to 24.9) can also be a health concern.

Many health care experts think BMI is a useful tool to measure weight and health risks, but others question its accuracy. Some believe a better way might be to take out the tape measure and check your waist circumference.

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BMIs, however, are only meant to be used by people between 18 and 65 years of age.