BMI and Why it Shouldn't Be the Only Measure of Weight Loss

Understanding weight loss and improving your overall health can be a daunting process, with many factors to consider. Yet, one of the most commonly cited metrics is the Body Mass Index (BMI). Initially designed to provide a simple way to categorise people based on their height and weight, BMI has become a go-to reference in discussions about fitness, health and weight management. But here’s the catch—relying solely on BMI might not give you the complete picture when it comes to your health and weight loss journey. 

What is BMI? How is BMI calculated?

First, let’s understand the basics of BMI. Body Mass Index, or BMI, is a widely used measurement that determines if your weight is appropriate for your height. It’s a simple calculation: divide your weight in kilograms by your height in metres squared. So the formula looks like this: BMI = kg/m², where "kg" is your weight and "m²" is your height squared. The result is a number that falls into categories: underweight, normal weight, overweight, or obese. It’s a quick way to get a general sense of whether your weight might be impacting your health.

Is BMI a Good Indicator of Health?

This is an interesting question. BMI is an extremely popular tool because it’s easy to use and offers a quick way to categorise people by weight. However, it has its flaws and isn’t necessarily a good indicator of health. It can be useful for broad population studies, but it’s not always accurate for individual health assessments and there are several reasons for this…

Why BMI is flawed:

1. It Ignores Body Composition

While bone density definitely plays a role, the main problem with BMI is that it doesn’t differentiate between muscle and fat. And this is a big deal because muscle weighs more than fat. To put this in really simple terms. Someone who is 200kg, completely sedentary, unhealthy and doesn’t have an ounce of muscle on them could have the exact same BMI as a 200kg bodybuilder who is pure muscle and puts in hours at the gym every day. If you look at these two people standing side by side, you’ll immediately doubt that BMI is an accurate metric for weight loss!

2. Fat Distribution Matters: 

Next, BMI is flawed because a person's fat distribution is left out. Now you might be thinking, what does this mean? When you weigh yourself, fat is fat, right? But not all fat is created equal. Fat around your abdomen, known as visceral fat or your ‘beer belly’, is much more dangerous than fat stored elsewhere. With excessive amounts of fat here, you’re more at risk for cardiovascular disease, type 2 diabetes, fatty liver disease and many more health problems. But BMI doesn’t account for this and two people with the exact same BMI could have very different health risks depending on where their fat is stored.

3.  One Size Doesn’t Fit All: 

Going right back to basics, BMI is misleading because it uses the same standards for everyone. And this just simply doesn’t make sense because body compositions differ based on age, sex, and ethnicity. Older people, for example, tend to have more body fat than younger folks at the same BMI. Women also often have a higher fat percentage than men with the same BMI.

4. Potential for Misclassification:

The rigid BMI categories can cause people to wrongly classify themselves, which could affect how they manage both their physical and mental health. We always say not to weigh yourself every day because your weight fluctuates based on a number of factors, but mainly because of your hydration levels. Someone who could be just above the “overweight” threshold on a certain day might think they’re unhealthy when they’re actually perfectly fine. This, unfortunately, has led people to adopt unnecessary - and possibly harmful - diets and exercise regimes or suffer from diminished self-esteem and body image issues.

5. Health is More Than a Number 

BMI simplifies health to a single number. When looking to lose weight, you should be looking to improve your overall health, such as fixing your poor sleep patterns, increasing your energy levels and reducing the risks associated with being overweight. You could reduce your BMI, but if you do it in an unhealthy way, your health could still suffer. It’s important to take a holistic approach to weight loss and focus on healthy, sustainable lifestyle changes rather than just aiming for a lower number on the BMI chart. This ensures that your path to weight loss is not only effective in terms of a number on the scales but also enriches your quality of life.

6. It Causes the Overprescribing of Obesity Treatments, like Ozempic 

Now, the last big reason BMI is flawed. BMI is the metric used by physicians to determine if an individual needs to be prescribed Ozempic,  the latest phenomenon, a diabetes drug that is being used to treat obesity. Now, don’t get us wrong, we do believe that people with an extremely high BMI who are putting themselves at severe risk of death would do well to be treated with Ozempic. 

However, Ozempic is being prescribed for individuals who are “categorised” by the BMI scale as obese (BMI ≥ 30) and overweight (BMI ≥ 27). And, as we’ve mentioned previously, having a BMI above these numbers doesn’t necessarily mean you’re overweight or have any risks to your health. What Ozempic then does, (when it works only 15-30% of the time) is drastically lower your BMI, potentially to dangerous levels on the other end of the scale! Also, if you’re being prescribed Ozempic and you don’t actually need it, - when a weight loss programme could do the job instead - once it gets rid of body fat, the treatment starts to break down your natural body muscle (we’re sure you’ve heard of Ozempic face). 

So BMI, a measure of weight that we’ve seen is already inherently flawed, is being used as the sole determiner for the prescribing of a drug that hasn’t been around long enough to see long-term effects. Shouldn’t a more accurate measure be used for such a life-altering decision? We think so.

Should BMI be Used? The BodySlims Take

With all this in mind, the BodySlims take on BMI is that, yes, it can be quite a crude measure, and it is flawed due to all the reasons mentioned above. BUT it can still have its place. If you check your BMI and find that you’re in the overweight category, it might be a good idea to take a step back and look at your health.  Checking your BMI can be the wake-up call you need and the catalyst to starting your weight loss journey. We’ve seen it make people realise, “Oh, I really am putting myself in danger”, and say to themselves, “It’s time I do something about this before it’s too late”.  But before you jump to the quick-fix solution of Ozempic or intense dieting, we encourage you to try our programme.

Dare to Dream with BodySlims!

Realising you need to change is half the battle; BodySlims can help you get the rest of the way there with our holistic approach to weight loss. We believe that weight loss happens when you take a step back off the scale and rid yourself of the bad habits and behavioural patterns that got you to the weight you are and replace them with good, healthy ones. We have thousands of success stories that prove once you change your mindset and adopt healthy habits, you’ll drop the pounds and achieve better overall health for good. 

So, sign up for our next programme intake today and get the weight loss transformation you’ve only ever dreamed of!