Is BMI Really the Best Measure of Health?
Body Mass Index (BMI) is one of the most common ways to get a snapshot of your overall health. Your BMI is calculated by dividing your weight (in kilograms) by your height (in metres), squared. It’s a quick, simple way to see whether you fall into the underweight, healthy, overweight, or obese range according to World Health Organisation (WHO) guidelines.
While BMI is a useful starting point, it’s important to remember that it’s just that — a starting point. It doesn’t take into account factors like muscle mass, body composition, or where fat is stored in the body. That’s why health and insurance professionals often use BMI alongside other key health indicators to get a more accurate picture of your metabolic risk.
Understanding Metabolic Risk
Metabolic risk refers to how your body processes and stores energy. It’s a major factor in assessing your risk for conditions like heart disease, diabetes, kidney problems, and even some cancers.
BMI can help highlight when further assessment might be needed, but other important measures include:
Blood pressure – high blood pressure (hypertension) can increase the risk of heart disease and stroke.
Blood sugar and insulin resistance – indicators of diabetes or pre-diabetes.
Body fat distribution – especially fat stored around the stomach (known as abdominal obesity), which can signal a higher risk of certain health issues.
If someone’s BMI is above a certain level, they might be asked to complete extra tests like blood work or a medical exam. These help professionals better understand overall health and ensure assessments are fair and accurate.
A Tailored Approach
When it comes to health — or insurance underwriting — there’s no one-size-fits-all answer. A high BMI doesn’t automatically mean poor health, just as a “normal” BMI doesn’t always mean everything’s fine. It’s about looking at the full picture.
At the end of the day, BMI is a helpful guide, not a diagnosis. By combining it with other health indicators, we can better understand a person’s unique risk factors and support them in living a longer, healthier life.