Have you ever wondered if your weight truly reflects your health? The BMI test is a quick assessment tool widely used by healthcare professionals, but does it tell the whole story? Explore why it matters—and what the limitations are in this guide.
What is BMI, or body mass index, is a medical screening tool. Healthcare professionals use it to measure the ratio of height to weight to estimate body fat. Doctors calculate BMI by dividing weight in kilograms by the square of height in meters.
Most people think BMI is similar to body fat — they assume the higher the number, the more body fat they may have — but it is not accurate. In addition, BMI alone does not determine health condition. Healthcare professionals of the health department use BMI as a tool to evaluate someone’s health status and risks.
Avoid using the standard BMI chart to assess a child’s or teenager’s weight or health condition. It is best to consult a doctor specialized in childcare about the ideal weight range for their age and height.
Here is the body mass index (BMI) table with categorisation for adults:
| Category | BMI |
| Underweight | Below 18.5 |
| Normal | Between 18.5–24.9 |
| Overweight | Between 25.0–29.9 |
| Class I Obesity | Between 30 to 34.9 |
| Class II Obesity | Between 35 to 39.9 |
| Class III Obesity | More than 40 |
Note that, BMI is not the only screening tool doctors use to classify weight types. They require other tools to:
One of the simplest ways to determine your BMI is by using an online free adult BMI calculator.
You only need to enter your height and weight in the respective fields. After submitting the details, the calculator will instantly compute your BMI score and indicate which category you fall into.
For example, if your weight is 70 kg and height is 185 cm, your BMI calculation will look like this: BMI = 70/1.85*1.85= 20.4
However, your BMR score does not determine your health condition. This measurement tool does not consider the significant factors including muscle mass, bone density or distribution of fat.
The ideal range for a healthy BMI is regarded as 18.5 to 24.9.
Remember that the amount of body fat you have is not the only factor that determines overall health. Several other remarkable factors, such as genes, activity level, habit of consuming tobacco, drinking alcohol and mental health status. These all can create a deep impact on your overall health and the chances of developing specific health conditions.
Here is why you should know your Body Mass Index (BMI):
BMI not only helps determine whether you are underweight, overweight, or at a healthy weight, but it also provides an indication of whether further evaluation is needed. The score helps you understand where you stand on the BMI scale and raises awareness of the risks associated with being underweight, overweight, or obese.
When an individual starts his weight loss or gain journey, he or she must know Is there any need to change, or your BMI is right. If it is needed to lose or gain weight, how much is necessary and will not have a negative impact on your health. Here, the BMI score plays a vital role.
It helps you determine how much you need to lose or gain to achieve the ideal body mass index according to your health requirements. It helps you decide an action accordingly.
In addition, knowing your BMI score helps you better understand your health condition and boost self-confidence. As per some studies, having an idea about your health encourages you to become your best version and boosts confidence. It also offers mental peace, as some medical findings suggest that not being at one's ideal weight can sometimes reduce confidence and even lead to depression.
BMI further guides healthcare professionals in making recommendations based solely on your health requirements. This makes the process more effective and ensures that specific needs are addressed.
Yes and no at the same time. Body Mass Index is a useful measurement tool for doctors to quickly identify potential health hazards. For instance, an individual with a high BMI score has a higher risk of developing heart disease and diabetes. However, only the BMI value can provide a detailed picture of your health.
It is important to consider other key factors such as lifestyle, current health condition, pre health status and family history that could affect your health. Additionally, do not solely rely on BMI score to have an accurate reflection of your unique body composition, such as how much fat versus muscle you have.
In short, while BMI can help assess one's health condition, it does not always provide a complete picture. This is where its limitations come into play (as discussed in the following section).
The standard BMI chart has certain limitations, so it is important not to rely too heavily on your BMI test result.
Although following the BMI chart may not be accurate for everyone, doctors continue to use it as it is the quickest tool for evaluating a person's body fat.
The limitations to diagnosing weight types are discussed in the following:
The standard BMI chart should not be used to evaluate body fat percentage in the following cases:
While the BMI score offers a quick assessment of body weight in relation to height, it does not tell the whole story. Having proper knowledge about its limitations, considering other health factors, consulting with a certified medical practitioner, following their advice, and acting accordingly help you make more practical decisions about your well-being and overall fitness.