We live in a world where we’re constantly told that we need to weigh less or have a perfectly flat stomach in order to be happy, acceptable and healthy.

Part of that misguided advice is the now outdated tool – BMI. As an accredited practicing dietitian I’m telling you, the measure of height versus weight to indicate health is incorrect and astonishing really that it’s still in use. 

History lesson alert: The body mass index was invented by a statistician, not a medical professional, Adolphe Quetelet nearly 200 years ago. He developed an equation of height (m)2/weight (kg) to assess population health trends, not individual health and as such BMI doesn’t take into account muscle mass, age, sex, fitness, race or any other metric. In other words, it’s a Euro-centric, gendered, pretty arbitrary and flawed measure that has absolutely no way of measuring your health.

Numbers are comforting, until they’re not. Image: Unsplash

People who use BMI to assess health need to catch up with the scientific literature – and common sense. According to BMI, a slim person who takes drugs, smokes, drinks too much alcohol, avoids exercise and eats unhealthily is assumed to be healthier than someone with a larger body who takes care of their body. Being underweight also has a higher mortality rate than being overweight. Plus, if you’re from any non-Anglo culture, BMI isn’t going to work for you. 

So why do we still use BMI?

We tend to rely on numbers and data as measures of our hard work. Numbers can be comforting, until they aren’t (my blog post Unhappy With Your Body Or Weight? might help). 

With the risk of heart disease, stroke, diabetes and certain cancers growing with our body mass index, BMI has been considered the most effective tool to calculate our health based on our bodies. But truly? The only reason it’s still in use is that a more effective and just-as-simple alternative doesn’t exist.

You can’t compare apples to oranges, just like BMI can’t tell your whole health story, so why are we still using it? Image: Unsplash

But it can also put people in a very unhelpful healthy and/or unhealthy box – and encourage weight loss when not actually required. Real health is measured by so many things such as energy levels, biomedical markers, mood and plenty more. It’s important to be healthy to feel good but don’t give up 95% of your life to weigh 5% less (my blog post The Best Diet To Lose Weight might help here. 

But what if my weight isn’t healthy?

The alternative to trying to define health by a single number is focusing on positive healthy habits and taking the microscope off of body weight and size. The best way to look after your health is to ditch the wellness wankery, forget your BMI and to learn to tune into your body instead. It’s the real health expert.