What is BMI? (and How Much Does It Matter?)
BMI uses your height and weight to estimate body size. Learn what it can and can’t tell you about your health in just a few minutes.
BMI, or Body Mass Index, is a simple tool that uses your height and weight to estimate whether you're in a healthy weight range. While BMI can be helpful, it doesn't tell the whole story about your health. That's why it's important to talk with your primary care provider about other factors, such as your blood pressure, cholesterol, blood sugar, and overall fitness.
You can calculate your BMI using your height and weight. BMI categories include:
- Underweight: Less than 18.5
- Healthy weight: 18.5 to 24.9
- Overweight: 25 to 29.9
- Obesity: 30 or higher
According to Meredith Presnell, APRN-CNP, of the MetroHealth Weight Loss Center, BMI is a useful screening tool because it's quick and easy to use. However, it doesn't measure body fat, muscle mass, or where weight is carried on the body.
For example, someone with a lot of muscle may have a high BMI but still be very healthy. On the other hand, carrying extra weight around the waist can raise the risk of health problems such as heart disease, diabetes, stroke, and fatty liver disease.
Looking Beyond the Numbers
At the MetroHealth Weight Loss Surgery and Weight Management Center, providers look at the whole picture, not just BMI. They may also review:
- Blood pressure
- Cholesterol levels
- Blood sugar (A1C)
- Physical health
- Emotional well-being
- Weight-related health conditions
"Numbers don't tell the whole story when it comes to obesity," says Presnell. "We're trying to improve health and quality of life."
We have to get past the idea that obesity is a cosmetic thing—that we lose weight to look better. Obesity is a chronic disease process, and we treat obesity because it’s often the root problem of other diseases.
Focusing on Better Health
The goal of weight management isn't simply to make the number on the scale smaller. It's about helping people feel better and lower their risk of serious health problems.
"We treat obesity because it is a chronic disease that can contribute to other health conditions," says Presnell.
Many people see important changes that go beyond weight loss, such as improved blood sugar levels, better liver health, easier movement, and more energy for everyday activities.
Those health improvements are what matter most. BMI can be a good starting point, but your overall health is much more than a single number.
“I’ve seen bodybuilders with 10% body fat, but a high BMI because of the amount of muscle they have,” says Presnell. “Numbers don’t tell the whole story.”
What does, says Presnell, are the overall health improvements she’s seen patients achieve.
“I’ve seen patient’s A1C levels drop, I’ve seen their fatty liver disease reverse, I’ve seen them be able to put their shoes on without getting out of breath,” says Presnell. “That’s the stuff that matters—not just the numbers you see on a scale.”
Ready to start your weight loss journey?
If you’ve struggled with obesity, you know that simply moving more and eating less doesn’t always work. That’s because obesity is a disease that changes your body. Sometimes, these changes can cause serious diseases like cancer, diabetes, heart disease and sleep disorders.
At MetroHealth, we work with you to set goals, choose treatment options and live a healthier life. You’re unique, and you deserve treatment that truly fits your needs.
Call 216-778-7433 or visit metrohealth.org/weight-management/.
Your Questions Answered
Q. What is BMI?
A. BMI, or Body Mass Index, is a number based on your height and weight. It helps doctors see if you may be underweight, at a healthy weight, overweight, or living with obesity.
Q. Does BMI tell me how healthy I am?
A. Not by itself. BMI is only one tool. Your doctor will also look at things like blood pressure, cholesterol, blood sugar, activity level, and overall health to get a better picture.
Q. Why might someone with a high BMI still be healthy?
A. BMI does not measure muscle or body fat. For example, athletes and people with a lot of muscle may have a higher BMI but still be in good health. That's why BMI is just one part of the conversation about your health.