The Body Mass Index, more commonly known as BMI, is an equation that took the health world by storm in the 70s.

Health professionals, doctors, nutritionists, and fitness professionals all shifted to using this method to measure the body composition and health of their clients.

However, the BMI was never intended to be used on an individual level. In fact, it wasn’t even created by someone in the health industry. Adolphe Quetelet, a Belgian mathematician, astronomer, and statistician, created the BMI to look at the weight status of groups on a population level.

When looking at the BMI of hundreds or thousands of individuals, we can use the BMI to assess the general health of a group or society, and for this, the BMI is a great tool; but when we zoom in and look at an individual’s BMI, the data gets a bit murkier.

The BMI is calculated by dividing a person's weight in kilograms by the square of their height in meters (kg/m²), using this number, it puts someone into one of the following categories: underweight, normal weight, overweight, and obese.

This doesn’t seem immediately problematic, but the issue lies in what it’s measuring. Looking at a person’s overall weight entails looking at everything that makes up their body: bones, organs, vitals, and muscles.

A popular example of why this doesn’t give us an accurate picture of someone’s health is a bodybuilder - or someone who strength trains regularly. They have a super low body fat percentage, and a much higher percentage of their body that is muscle.

But, as many say, muscle weighs more than fat. In fact, a pound of muscle is 20% denser than a pound of fat and takes up 20% less space.

This is why two people who are the same height and overall weight can look drastically different visually, even though they fall into the same range on the BMI scale.

If the BMI isn’t a good measure of individual health, then what is? Here are the current tests and measurements that can give us a better understanding of our personal health.

Body fat percentage, which distinguishes between fat mass and lean mass. It can be measured using tools like skinfold calipers, bioelectrical impedance analysis (BIA), or dual-energy X-ray absorptiometry (DEXA) scans.

Waist circumference and waist-to-hip ratio are also useful indicators, as they help assess abdominal fat, which is linked to a higher risk of metabolic diseases like diabetes and heart disease.
Cardiorespiratory fitness, often measured through VO₂ max tests, provides insight into heart and lung efficiency.

Blood tests measuring cholesterol levels, blood sugar, and inflammation markers offer a deeper understanding of cardiovascular and metabolic health.
Monitoring blood pressure, resting heart rate, and strength/mobility assessments can help evaluate overall physical health.

Body Scans are the lowest-tech option, but they are also very effective. Checking in with how we feel and how our body is functioning regularly can help us recognize when things improve, but more importantly, when things aren’t running smoothly. It teaches us to recognize health in our own bodies rather than simply relying on other systems to measure it for us.

Using these measurements and approaching our health with a holistic approach such as considering lifestyle habits like diet, sleep, and mental well-being, provides a far more accurate picture of an individual’s true health status than BMI alone.

If you need help, give us a call today at 408-370-1739! Our certified fitness and nutrition coaches can help keep you accountable and move you closer to living the life you envision!

Mint Condition Fitness is the #1 rated personal training studio in Los Gatos for adults 50+ to take control of their fitness and live the life they envisioned.