BMI and fat ratio: Only one of these two indicators is really important

Both BMI and body fat percentage are used to measure whether your body is healthy or not. But actually you only need to use one of the two indicators, because BMI is not a magic number as you think.

You may have heard of and had a BMI, or body mass index, at the clinic or school.

You can measure your BMI with just a scale, but in terms of health indicators, this indicator is not accurate. (Image: Malte Mueller / Getty Images).

Although the BMI is widely used in health monitoring, it turns out it is not completely accurate, especially for different ethnic groups. Instead, what we need to consider is the proportion of body fat and the density of fat distribution on the body . These two indicators will let you know your overall health status more accurately.

If you are curious about the origin of BMI and want to find out why body fat percentage is related to health, read on this article, we will help you answer those questions.

Origin of BMI

The first person we need to mention is a Belgian statistician named Lambert Adolph Jacque Quetelet, who came up with the concept of "social average" . He studied the definition of "the average human being" and wanted to find out a fat distribution ratio so that his body would have the best waist circumference. In 1835, Quetelet found a formula for calculating the relative accuracy of body mass and height, which is the height divided by the square of weight. And since then, the formula for calculating body mass index was born, although at that time it was not called by this name.

Although much involved in mathematics, however, the important thing is that Quetelet is not a physicist or health researcher, he is only looking to analyze the population. Quetelet's index does not distinguish between muscle and fat, it only cares about the total weight of the body. So why is BMI used as a health indicator ?

Table of BMI. (Photo: IIFYB).

In the 1970s, researcher Ancel Keys conducted a test on 7,500 people to find the most effective way to measure body fat. After testing, calculating your body mass index, hydraulic measurements and skin thickness measurements are the three most effective and least expensive ways to measure body fat. One problem, however, was that all Keys' study participants were male and white.

Moreover, by 1985, the National Institutes of Health changed the definition of obesity, including the definition of BMI. Accordingly BMI is "a simple calculation equivalent to other fat measurement calculations". Therefore, BMI has become a simple way to calculate the risk of obesity-related diseases.

Why is BMI incorrect?

Not because they are simple and not expensive, they will not be accurate for everyone. One reason is because the density of muscle is greater than fat. So if your body has a low percentage of fat but your weight is higher than average compared to your height, your BMI may indicate you are obese, although not at all.

In a study of thousands of people, African-American women were in better health than white women despite having similar BMI after they had their blood pressure and cholesterol tests done. Therefore, it is possible that the BMI shows that blacks are "not healthy", despite the opposite.

Several other studies have had similar results. A researcher at the University of Tennessee also concluded that: "Compared with whites, African Americans of the same age, gender, waist circumference, weight and height may have total fat and fat content. lower belly fat ". Therefore, BMI will evaluate these people with the actual fat and means that this index is inaccurate.

BMI is also misleading when it comes to Asians, but in the opposite direction to African Americans . A health monitoring study of more than 78,000 women in the US found that Asian Americans are at a higher risk of obesity-related illnesses at a lower BMI than whites.

BMI and fat ratio

Now we know why BMI is not a magic number to calculate the health of the body as well as detect the risk of diseases. We will show you a much more accurate way to measure body fat percentage.

The ratio of fat has proven its accuracy in detecting the risk of osteoporosis, diabetes and other high-risk diseases in general, although the BMI of these people is still normal.

Scientists currently do not understand the relationship between BMI, fat percentage and obesity. But the reason the fat percentage can help make an accurate diagnosis may be because it calculates based on the amount of fat and the rest of the body , not all of them as BMI.

How to measure the ratio of fat?

Just in front of the Naked Labs Body Scanner, this device can calculate your body fat percentage. (Photo: Tyler Lizenby / CNET).

There are many ways to measure your body fat percentage, but for the most accurate results, you should consult a clinic or see a nutritionist . At specialized clinics, there will be the most accurate measuring equipment such as hydraulic scales or DEXA scanners.

If you cannot afford to go to specialized clinics, you can still measure yourself at home. The United States Fitness Council has some devices that can measure relative fat percentage by measuring skin thickness.

However, the percentage of body fat is still not enough to correctly conclude about your body condition. The location of body fat is also a matter of concern. Some people accumulate fat in the belly area, but some also accumulate fat in the "V" area below the abdomen, or some other position such as the chest, hips . The density of fat distribution on the body may be due to weakness environmental factors, such as alcohol or tobacco use, but it is also strongly influenced by genetic factors.

To find out the fat density distribution on your body , you can measure the ratio between your waist circumference and your waist circumference . The greater the amount of fat stored in your waist (the apple-shaped and vice versa the pear-shaped form), the higher your risk of cardiovascular disease. Rates above 0.85 in women and over 0.9 in men are thought to be at risk of obesity-related diseases.

If your waist-to-hip ratio or body fat percentage is higher than you want, don't worry, as this number can vary. A 2011 study found that diets reducing overall food intake can reduce waist-hip ratio. If you are interested in reducing fat percentage, talk to your doctor or health care services. They will help you set up a long-term weight management plan to fit your condition.