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BMI vs. Body Fat

Sep 22, 2015

Body mass index (BMI) is used to screen for body weight problems based on a person’s height and weight. BMI is determined by taking a person’s weight in kilograms divided by the square of their height in meters. Commonly used by doctors, this number is intended to classify people into one of four weight categories: Underweight = <18.5, Normal weight = 18.5–24.9, Overweight = 25–29.9, Obesity = BMI of 30 or greater. The big misconception with BMI is that it is intended to measure a person’s body fatness. BMI is purely a height and weight equation, and may indicate a high level of body fat; however anyone with a lot of lean muscle will always be classified in a higher category.

For example Rob Gronkowski is 265lbs at 6’6” with a BMI of 30.6! Last time I checked Gronk has a 6 pack, but he falls into the obese category in BMI.

The measure of a person’s body fat percentage is a much better way screen for body weight issues. Body fat can be calculated many ways including skinfolds, hydrostatic weighing, Dual-energy X-ray absorptiometry (DXA) scans, and using scales or hand held devices which electronically measure body fat using bioelectrical impedance.

According to the American Council of Exercise, Body fat measurements fall into one of the following categories.

If you are curious about your body fat percentage, ask any of our Fitness Together personal trainers to measure yours.



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