What is the importance of BMI? And, more importantly, do you know your own BMI?
Don’t those questions immediately fill you with dread and just encourage you to think up several other questions? These questions come across more intimidating than helpful.
That’s why we created this blog- to walk together through the aspects of BMI. We are going to explore the importance of BMI, how to calculate it, and what that means for our health.
Let’s get started!
What is BMI?
BMI was originally called the quetelet index (try to say that 5 times fast) and was created by Adolphe Quetelet in 1832. Thankfully, the name was later changed in 1972 by Ancel Keys to the body mass index, commonly shortened to BMI today.
It is the measure of body fat based on your height and weight. BMI is used to screen whether you are underweight, a healthy weight, overweight, or obese. Although BMI can't be used as a diagnostic tool, doctors do use it to find your health risks.
There are two main ways to calculate your BMI. One is to use a BMI chart or table. You find your height and slide your finger over until you reach your weight. You can also use one of the various online BMI calculators.
BMI = (your weight in pounds x 703) ÷ (your height in inches x your height in inches)
Here are the ranges of BMI:
Underweight: BMI is less than 18.5
Normal weight: BMI is 18.5 to 24.9
Overweight: BMI is 25 to 29.9
Obese: BMI is 30 or more
How accurate is BMI?
BMI is an estimate of body fat using a mathematical formula. As such, there are instances where BMI can be inaccurate. For example, athletes with more muscle build will get a higher BMI than would be accurate. The Elderly who have lost muscle mass would get a lower number.
In children, they add a growth chart to the regular BMI chart. This adds their age and gender to get a percentage instead of a number like adults would receive. For children, the 85th percentile and 95th percentile are considered overweight and obese.
So why use BMI?
Skinfold thicknesses, bioelectrical impedance, underwater weighing and dual energy X-ray absorption, are other measures of body fat that can be more accurate than BMI. BMI is used more often because of how easy it is to calculate. BMI is also non-invasive and cost-effective making its use more sensible and available than its counterparts.
Health risks of a higher BMI
Here’s why BMI matters. The higher your BMI, the more health risks you need to consider. High BMI means you could be at risk for heart disease, high blood pressure, type 2 diabetes, gallstones, osteoarthritis, and sleep apnea. You could also be at a higher risk for certain types of cancers, like colon cancer, breast cancer, endometrial cancer and gallbladder cancer. The importance of BMI is one of the first factors health professionals consider when evaluating health risks.
Current estimates suggest that up to 365,000 excess deaths occur each year due to obesity in the U.S. BMI is a good way to recognize a person's health risks and implement plans to reduce those risks. Diet and exercise are the best ways to manage weight concerns.
There is no way to overstress the importance of BMI. Although BMI isn't 100% accurate, it is a good starting place to identify health risks. Then, to mitigate health risks, exercise and diet are instrumental. Independent of any particular disease, people with high BMI often report feeling better, both physically and psychologically, once they lose excess weight.
A way to improve BMI is simply to stand up and move more throughout the day. Whether it is using a standing desk while in class, going for a walk, playing a sport, or a combination of all of the above it is important to add movement to your day. A couple of simple changes to your day add up to provide a lifetime of benefits.