If you’ve had a standard checkup with your doctor or other health care provider, they may be able to calculate your BMI. It’s a simple formula that uses your height and weight to determine if you’re carrying too much fat.
It’s been the standard way to assess a person’s health since the early 20th century (with modifications along the way), but while it gives a good snapshot of a person’s condition, it’s such a simple test that it’s not a complete picture. and should be considered in conjunction with other considerations.
To get the most accurate picture of a person’s health, it’s important to look at what their BMI is do not take into account. While BMI is a good starting point, taking into account a person’s age, gender, ethnicity, and build can help provide a better picture of that person’s condition and whether they need to make lifestyle changes. There are other ways to measure body fat (opens in new tab) this may be more accurate, but these are often based on more complex calculations.
Contributed by: Dr Juliet McGrattan
A doctor in the UK for 16 years, Juliet McGrathtan is now an award-winning author and trainer. In addition to his years as a GP, he was the lead clinical champion for physical activity in the North West for Public Health England. (opens in new tab).
What exactly is BMI?
BMI stands for “Body Mass Index” and is often used to determine whether a person is at risk of becoming obese. BMI measurement is related to many obesity-related health issues, so it is a valid starting point when looking at a person’s health status. It is also easy to understand because it is based on a numerical scale.
Each entry on the scale corresponds to the number of kilograms per square meter (so BMI is 25 25 kg/m²).
According to CDC data (opens in new tab), a BMI of less than 18.4 on the scale is considered “underweight.” For most people, a BMI between 18.5 and 24.9 is considered normal or acceptable, while people between 25 and 29.9 are considered “overweight.” Anyone with a BMI of 30 or higher is considered “obese.”
However, since a person’s BMI does not focus solely on fat, but also includes muscle and other tissues, it is not a complete assessment by itself.
| BMI | Weight status |
|---|---|
| Below 18.5 | low weight |
| 18.5 – 24.9 | Normal |
| 25.0 – 29.9 | overweight |
| 30.0 and above | obesity |
How can I calculate my BMI?
To work out your BMI, you need to know:
- How much do you weigh?
- How tall are you?
These can be metric or imperial measurements. Both have a formula.
For metrics, you simply calculate your height in centimeters squared and use that number to divide your weight in kilograms (weight ÷ height²).
Calculate your height (in inches) for Imperial and use the number to divide your weight in pounds (weight (lbs) ÷ height (d)²). Multiply by 703 again this time.
For an easy way to work out your BMI, you can enter your weight and height and use one of the many online calculators that calculate it for you.
What is BMI used for?
Health care professionals use BMI to help assess their patients’ risk factors for certain weight-related health conditions.
“Measuring your BMI can help you and your nurse or doctor determine if you are healthy.” says Dr. Juliet McGrathtan, former physician and author of Sorted: The Active Woman’s Guide to Health (opens in new tab). “There are health risks associated with being overweight and being underweight.”
Working out your BMI is not only useful on a personal level, however. “BMI can be used at an individual level to help you decide whether you need to gain or lose weight, but it is also used at a broader level to indicate the health of a population,” adds Dr McGrathtan.
Thus, knowing the average BMI of a population, along with other health statistics, can give health professionals more information about how to target communities that need additional help with their lifestyles and health care options.
Should I be concerned about a high or low BMI?
If you’ve entered your information into the calculator and the results aren’t within the “healthy” range, don’t panic.
“It’s important to know that BMI is just a guide and can be misleading for some people. For example, if you are very muscular, your BMI may indicate that you are overweight when you are otherwise healthy,” says Dr. McGrattan.
However, you should always check if you’re not sure, because there are risks associated with being on both sides of the “unhealthy” parameters:
“If your BMI is outside of the healthy range, it’s a good idea to discuss it with your doctor,” adds Dr. McGrattan. “A BMI that’s too low can put you at risk for medical conditions, including osteoporosis, where bones are thin and break easily.
“There are also many known health risks associated with being overweight or obese, such as type 2 diabetes, heart disease, and many types of cancer. Your doctor can help you determine what your BMI means for you personally and what steps you should take to correct it. .
Is BMI an accurate measure of my health?
BMI is a good starting point, but some researchers argue that BMI is not a good measure of a healthy weight. As McGrath explains, “Your BMI doesn’t tell the whole story. A person with a BMI in the normal range can be unhealthy if they don’t exercise regularly, or if they smoke or drink too much alcohol.
“Also, someone with a higher BMI may be fitter and healthier than someone with a lower BMI. It all depends on their lifestyle and habits. BMI should always be interpreted in conjunction with other factors such as a person’s lifestyle, ethnic group and other medical conditions.
As mentioned earlier, the main disadvantage of BMI is that it does not measure only the amount of fat, nor does it measure the distribution of fat in the body. Therefore, it is important to look at the BMI score along with other tests, such as waist measurement, to quickly determine whether a person is healthy or needs extra help.
“Also, good overall health includes both physical and mental health, and remember that BMI does not measure your mental health,” says Dr. McGrattan.
BMI remains a good way to quickly get a picture of a person’s health, but is not a one-size-fits-all solution and must be considered along with other factors such as lifestyle, body composition, gender, age, ethnicity and general health. private.
If you have health concerns about your BMI, ask your doctor or nurse for advice.
This article is not intended to provide medical advice and readers should consult their physician or health care professional before adopting any diet or treatment.