24/08/2026
For decades, BMI has been one of the main ways we define and measure obesity.
But we are starting to understand that our focus is flawed.
BMI doesn’t tell us:
• How much of that weight is fat vs muscle
• Where the fat is distributed
• How much intra-abdominal fat is present
• Whether we are preserving muscle during weight loss
• What our metabolic health looks like
• How obesity is affecting our function and quality of life
Two people can have the same BMI but very different body composition, health risks and treatment needs.
Recent evidence and IFSO guidelines are moving towards driving management according to clinical obesity which places more emphasis on obesity related metabolic disease (like diabetes, heart disease, high blood pressure, sleep apnoea) rather than a single BMI number.
As obesity management evolves, we also need to be much more obsessed with body composition which accounts for muscle, fat and fluid percentages.
We should move away from just asking:
“What is your BMI?”
And start asking:
“What is your body composition?”
BMI can be a starting point.
It shouldn’t be the whole story.
It’s time to look beyond the number.
