Understanding Your Weight and BMI
Watching your weight is critical to good health, but many people don’t really know what their correct weight is. Understanding your BMI – or Body Mass Index – is the key to understanding what your weight should be. A person’s BMI is calculated based on weight and height, and it provides a good indication of how much body fat you might be lugging around.
How is BMI Calculated?
BMI measures pounds versus inches. The formula looks like this:
BMI = (weight in pounds X 703) / (height in inches X height in inches)
First, you would multiply your weight (say 192 pounds) by 703 (the “magical number” in the formula), which equals 134,976. Then you would multiply your height in inches (5’10” =70”) by itself, resulting in 4,900. Dividing 134,976 by 4,900 gives us 27.5 (rounded off). Now you’re ready to compare that result against the standard Body Mass Index chart.
Instead of doing the calculations yourself, you can use any of the many BMI calculators available on the web, such as this one from the U.S. Centers for Disease Control and Prevention site.
What Are the Ranges for Body Mass Index?
Here is the current Body Mass Index Chart:
Underweight: below 18.5
Normal: 18.5– 24.9
Overweight: 25.0 – 29.9
Obese: over 30.0
So, where does the aforementioned 5’10″ man weighing 192 pounds with a BMI of 27.5 fall on this chart? That fellow falls within the BMI range for an overweight person (25.0- 29.9).
But since BMI is calculated based on height, a 6’0″ male weighing the very same 192 pounds would have a BMI of 24.7 – falling into the normal weight range.
Limitations of BMI – Talk to Your Doctor
Knowing your height and weight and calculating your BMI may be important, but it isn’t the last word on your health or your weight. Since muscle weighs more than fat, well-conditioned athletes and even people with a stocky build (see, mom wasn’t just being nice when she told you that you were “big-boned”) may find that BMI is not an accurate measure of their health or the amount of body fat they’re carrying around.
Because BMI is just a general measure based on typical body conditions, it’s an absolute must for you to speak with your physician about your weight. Even if you don’t have specific concerns, routinely reviewing where you are and where you’ve been weight-wise with your doctor is important. Sudden spikes and dips in your weight could indicate other underlying medical conditions. Remember that our bodies settle at different weights with different amounts of body fat based on a number of factors, including gender, conditioning and age.
Is BMI a Useful Tool for Monitoring Health?
Despite its limitations, BMI gives us a useful tool for keeping a watchful eye on our health and comparing our own weight with that of the general public. In fact -with so many BMI calculators available online – the hardest part may very well be working up the courage to step up onto the scale itself!
And – for your health – that could be the most important step you ever take.
Have you calculated your Body Mass Index and talked to your doctor about it? What happened?
