More Than Just a Number: Why Body Composition Beats BMI

By Dr. Navi Muradali, MD

For years, doctors, including myself, and health experts have used Body Mass Index (BMI) to determine if someone is at a healthy weight. But recent research shows that BMI isn’t as reliable as we once thought. It doesn’t take into account important factors like muscle mass, fat distribution, and overall body composition. That’s why more and more experts are now turning to body composition analysis as a better way to assess health risks.

Why BMI Falls Short

BMI is a simple formula that divides weight by height. It’s a quick way to categorize people as underweight, normal weight, overweight, or obese. But the problem is, it doesn’t paint a complete picture of health. Here’s why:

• It Doesn’t Differentiate Between Fat and Muscle: BMI classifies people based only on weight. This means a muscular athlete could have a high BMI and be labeled overweight, even though they have little body fat.

  
  

• It Doesn’t Show Where Fat is Stored: Not all fat is the same. Visceral fat (the kind that surrounds internal organs) is more dangerous than subcutaneous fat (the fat under the skin). BMI can’t tell the difference.

  
  

• It Ignores Differences in Body Type and Ethnicity: Research shows that BMI isn’t equally accurate for all body types or ethnic backgrounds. For example, some people may develop health risks at a lower BMI than others.

  
  

• It Doesn’t Always Predict Health Risks Well: Many people with a 'normal' BMI still have serious health conditions, while others with a high BMI are perfectly healthy.

  
  

Why Body Composition is a Better Measure

Body composition analysis looks at how much of your body is made up of fat, muscle, bone, and water. This gives a much clearer picture of overall health. Here’s why it’s better than BMI:

• It Distinguishes Between Fat and Muscle: This helps prevent people with high muscle mass from being misclassified as overweight.

  
  

• It Focuses on Visceral Fat: Visceral fat (fat around the organs) is linked to serious health problems like diabetes and heart disease. Body composition analysis can measure this.

  
  

• It Helps Create Personalized Health Plans: Knowing your exact fat percentage and muscle mass allows doctors to make better recommendations for improving your health.

  
  
  
  

  

  
  
  
  

The Dangers of Visceral Fat

Visceral fat is the hidden fat around your organs, and it’s linked to several major health risks, including:

• Type 2 Diabetes: Too much visceral fat makes it harder for your body to control blood sugar levels.

  
  

• Heart Disease: This fat contributes to clogged arteries and heart problems.

  
  

• Liver Disease: It’s a leading cause of non-alcoholic fatty liver disease (NAFLD).

  
  

• High Blood Pressure: More visceral fat often means a higher risk of hypertension.

What the Research Says

• A 2019 study in The Lancet found that BMI misclassified nearly half of individuals when it came to obesity-related risks.

• A 2021 study in Obesity Reviews showed that body fat percentage and visceral fat are much better indicators of health than BMI.

• A 2022 study in JAMA Network Open found that people with a normal BMI but high visceral fat had a much higher risk of dying early.

• A 2023 study in Nature Medicine confirmed that tracking visceral fat is the key to effective weight management.

  
  

The Bottom Line

BMI is still widely used, but it’s clear that body composition analysis is a more accurate way to assess health. By measuring muscle mass, fat percentage, and visceral fat, we can get a much better picture of overall well-being. If you want to understand your health better, consider focusing on body composition rather than just BMI.

Editors note: Body Composition can be done using a BIA Scale at some clinics and centres. Discuss with your dietitian, trainer or doctor. While a DEXA scan may be more accurate it is costly and not widely available.