What is Body Roundness Index (BRI)?
The Body Roundness Index (BRI) is a health metric developed by mathematician Dr. Diana Thomas in 2013. Unlike BMI, which treats the human body as a cylinder (using only weight and height), BRI models the body as an ellipse. It quantifies how close your body shape is to a circle. A perfect circle would represent a high score (high visceral fat), while a lean, linear shape represents a low score.
Why Doctors Are Switching to BRI
A major study published in JAMA Network Open in 2024 has brought BRI into the spotlight. The study, which analyzed health data from over 32,000 adults, found that:
- BRI predicts mortality better than BMI: It showed a stronger correlation with all-cause mortality.
- It catches "Skinny Fat": BRI identifies individuals with normal weight but dangerous levels of central (belly) fat, whom BMI would classify as "Healthy."
- It creates a U-shaped risk curve: Both very high and very low scores are linked to health risks, giving a clearer picture of longevity.
Interpreting Your Score (JAMA 2024 Standards)
| Score Range | Zone | Health Implication |
|---|---|---|
| < 3.4 | Very Low | Possible frailty or malnutrition (especially in elderly). |
| 3.4 - 5.5 | Healthy Zone | Assoc. with lowest all-cause mortality. |
| 5.6 - 6.9 | Mildly Elevated | Increased metabolic risk. Monitor waistline. |
| 6.9 - 10.0 | Moderate Risk | High correlation with metabolic syndrome. |
| > 10.0 | High Risk | Significant cardiovascular risk factors present. |
Frequently Asked Questions
Is a lower score always better?
No. Unlike body fat percentage where "lower is better" is often the simplified rule, BRI has a "U-shaped" curve. Examining the JAMA data, scores below 3.4 were also associated with higher mortality, often due to muscle wasting, frailty, or underlying illness. Aim for the "Goldilocks Zone" of 3.4 to 5.5.
How do I lower my BRI?
Since your height is generally fixed, the only variable you can change is your Waist Circumference. Reducing visceral fat is the most effective way to lower BRI. This typically involves:
- Incorporating high-intensity interval training (HIIT).
- Reducing sugar and refined carbohydrate intake.
- Managing stress (cortisol) and getting adequate sleep.
Tools & Data Verified by the EverydayCalculators Medical Research Team.
Last updated: January 2026.