HOW WELL DOES THE BMI MEASURE YOUR HEALTH?
I see lots of athletes in my office with an elevated BMI. Does that mean they are unhealthy? Of course not!
So what does the BMI or body mass index really mean? And how well does the BMI measure your health? In this blog, let’s look at how the BMI might be used and some of the disadvantages of looking at this measure alone to assess your health.
What is the BMI?
Your body mass index is a general measure of your body mass (muscle, fat, and bone). You calculate the BMI by dividing your weight (in kilograms) by your height (in meters squared). Based on this number, you can be categorized as being underweight, normal weight, overweight, or obese.
So how do people use this information?
How Professionals Use the BMI
Researchers can use the BMI to look at general population trends for overweight and obesity. Public health officials can also look at the general health of certain groups – like those people who have type 2 diabetes.
Health providers might use the BMI to track someone’s progress if they are trying to lose weight. Or providers might use it to find health problems if someone has a BMI in the underweight or obese category.
But how well does the BMI measure your health? That’s where things can be much less clear.
The Disadvantages to the BMI
The BMI can’t distinguish muscle mass from body fat. Many athletes have a lot of lean muscle. And muscle weighs more than fat. So a muscular athlete may have an elevated BMI but be very healthy. Measures like waist size and body fat analysis can be more helpful in looking at body composition.
Tall people may also have an elevated BMI because the calculation is made using total body surface area. And taller people simply have more surface area as part of their calculation.
Functional Fitness
Someone might have a BMI in the normal category but have poor health or fitness levels. How well someone can perform daily activities like walking, climbing stairs, or lifting things like grocery bags can provide more information about general health. Fitness experts call that functional fitness.
The BMI also can’t account for individual variations. So two people with the same BMI might have drastically different levels of health and fitness. Looking at someone’s medical history, genetics, and functional fitness becomes more important.
So Why Use the BMI at All?
The BMI can be a quick starting point to assess someone’s health. But people should also consider:
· Genetics or family history
· Level of functional fitness
· Other health conditions
· Other measures of body fat composition like waist size or body fat percentage
If you would like to work on your functional fitness, schedule your FREE fitness evaluation at the Pittsburgh Fitness Project. We look forward to working with you on your fitness journey.