For decades, BMI or body mass index has been used to indicate a person's health based off of their body weight. This test takes a person's weight and divides it by their height, which would categorize their body weight as "low", "normal", "overweight", or "obese".

While this formula is pretty straightforward, it comes with its own set of issues. The main issue being it only takes your height and weight into account, without considering fat distribution or muscle mass.

Muscle is denser and weighs more than fat, so the number on the scale might not accurately reflect how healthy or in-shape you are.

BMI and Body Image Issues

When I was in high school in the early 2000's, BMI was still the standard for healthy or unhealthy body weight. I was an athlete - I swam, played water polo, lifted weights, and ate healthy, home-cooked meals.

But whenever I went to the doctor for a physical, they would put me on the physician's scale (you know the one with the little sliding weights?) They would tell me to hop on, and tick, tick, tick would go the little weight as the number went up.

I hated that part. I hated when the nurse would go "mmmkay" and write down a number on her notebook, not looking me in the eyes. Let's be clear. I wasn't fat by any means. I was small - 5 feet tall, size 4 jeans, size small shirt. But I had a lot of muscle, even as a kid.

But that didn't matter to BMI standards.

They saw a 140 pound 14 year old and thought I was overweight. And it wasn't just at the doctors. Remember the Wii Fit scale? My Mii was always "at risk of overweight" according to my BMI.

I know now that I probably wasn't alone in feeling this way. Studies show that BMI can be linked to negative opnions about body image, especially in students and young adults. (1)

I struggled with body image issues, wondering how I could be considered nearly overweight when I worked out everyday and ate clean. It took me years to realize that BMI wasn't the most accurate way to determine how healthy I was. It wasn't until I was a couple years into college that I found better alternatives. One of those being BRI or body roundness index.

What is Body Roundness Index?

While BMI only takes your height and your weight into account, BRI uses your height, waist size, and hip size. It completely takes the number on the scale out of the equation, and instead, determines your health and risk of heart disease by the amount of belly (or visceral fat) you have.

BRI is a little more difficult to calculate by hand, but you can use an online calculator to help you. All you need is a measuring tape to measure your height and waist circumference.

For example, if you're 6 feet tall and have a waist circumference of 32 inches, just plug that into the online calculator and get your BRI.

BRI is scaled from 1-16 or higher. The higher the number, the greater your risk of metabolic and cardiovascular disease.

1-4 = very low body fat

4-7 = healthy/normal body fat

7-9 = overweight

9-12 = obese

12+ = severly obese

Belly fat is not only frustrating, but it is also linked to high blood pressure, heart disease, diabetes, and cancers.

So, how much more accurate is BRI versus BMI?

In one study, 33,000 people had their BRI recorded and were followed for 20 years. Those with a higher BRI were associated with an increased risk of death compared to those with a lower BRI. In fact, people who had a BRI of 6.9 or higher had nearly a 50% higher risk of early death compared to those with a BRI of 4.5 to 5.5. (2)

BRI: The New BMI

For years, so many of us grew up believing that a single number could define how healthy or unhealthy we were. But the truth is, health is a lot more than just weight divided by height.

BMI might be easy to calculate, but it often misses the full story. It doesn’t account for muscle mass, fat distribution, or what’s really happening inside your body. And for many people, it’s been the start of unnecessary shame, confusion, and body image struggles that could have been avoided.

Thankfully, BRI has helped give us a better representation of heart health. It gives a better picture by focusing on waist size and visceral fat—the factors that actually have a major impact on your heart health and longevity.

So if you take anything away from this, let it be this: your health is about so much more than what you weigh. And you deserve to measure it with something that truly sees the full picture.

Sources:

(1) Musaiger, A. O., Al-Mannai, M., Tayyem, R., Al-Lalla, O., Ali, E. Y., Kalam, F., & Chirambo, V. "Body mass index perception, body image dissatisfaction and their relations with weight-related behaviors among university students." International Journal of Environmental Research and Public Health, vol. 16, no. 9, 2019, article 1541. PubMed Central, PMCID: PMC6539402.

(2) Solan, M. "Body roundness may beat body mass for identifying risky fat." Harvard Health Publishing, Harvard Men's Health Watch, reviewed June 2024. https://www.health.harvard.edu/staying-healthy/body-roundness-may-beat-body-mass-for-identifying-risky-fat. Accessed April 28, 2025.