You might think obesity is just about being overweight. But what if I tell you that you could have a normal weight and still be clinically obese or have BMI and be perfectly healthy? In this blog, I will explain to you how we as doctors assess obesity. Not just by the scale, but how we measure how much fat you have, where it is concentrated, and what it is doing to your organs, your daily life and your future health.
BMI: the good and the bad
In our clinics, we usually start by calculating what we call the body mass index (BMI). This is the most common method for understanding obesity in a person. To figure out your BMI, we use a simple equation:
For example, if you weigh 90kg and you are 1.75m tall, you would have a bmi of 29.4, which is usually considered overweight by BMI standards.
Now on paper it sounds like a quick and easy way to understand your body composition. But BMI doesn’t tell you the whole story, it only tells you how heavy you are on a scale. Is it bone, muscle or fat? If we look at someone like Arnold Schwarzenegger, he was considered to have one of the greatest physiques of all time. But he had a BMI of 31. So what’s wrong? Well, he had a lot of muscle and muscle is much heavier than fat. So while BMI is a very good starting screening tool, it’s not enough, especially for those with lots of muscle. So we need to go deeper to try and find other tools that can tell us about obesity.
