The BMI number that is calculated just from weight and height is really just a number that tells us we need to go look at some other numbers. The other numbers are things like body fat percentage, cholesterol levels, blood pressure, blood sugar, etc. It is entirely possible for someone to have a “normal” BMI and still be very fat and unhealthy, and those people are pretty easy to identify visually, just as someone with a “high” BMI who is a powerlifter or something is very easy to visually identify.
The BMI number that is calculated just from weight and height is really just a number that tells us we need to go look at some other numbers. The other numbers are things like body fat percentage, cholesterol levels, blood pressure, blood sugar, etc. It is entirely possible for someone to have a “normal” BMI and still be very fat and unhealthy, and those people are pretty easy to identify visually, just as someone with a “high” BMI who is a powerlifter or something is very easy to visually identify.