What is a Healthy BMI and Why it Matters?

We all want to achieve a healthy weight. The simplest way to know if you are overweight is using a weight chart by age. We have all seen this chart in a doctor’s office or these days on many internet websites. 

This weight chart was the answer to the question: How do I determine my ideal weight? It is a simple chart that has height on one side and weight on the other side. You pick your height and it tells you your healthy weight. The detailed table at the end of this article is based on NIH Body Mass Index Table.

You can check your ideal weight by having a look at the table. There is also a variation which is weight chart by age but that is mostly for measuring children weight since birth to ensure that they are growing well and are not malnourished. 

But there is an even simpler way to know if you are overweight or not. It is called BMI chart. 

What is a Healthy BMI?

So, what is a normal BMI? According to the Center for Disease Control and Prevention, the following BMI ranges have been identified: 

So, if your BMI is 25 or higher, it will mean that you are not in the normal BMI range. Also, a BMI reading of less than 18.5 means that you are underweight.?A healthy BMI range is between 18.5 to 25.

How do I Calculate my BMI?

The easiest way is to use the chart at the end of this post to find the reading corresponding to your healthy weight. There are also many BMI calculators for kids and adults online. You can easily use a BMI calculator

But if you want to know how exactly MBI is calculated, then you need to understand the BMI equation. The formula used for calculated BMI is weight in kg/height in square meters(kg/m² ).

 If the weight is in pounds and height in inches, then the formula is weight in pounds/inch² x 703. However, BMI calculator for adults is more or less accurate for ages 18 to 65. For children and older people, there are different BMI calculators. 

Is BMI Accurate?

But is BMI reliable? While BMI is an excellent predictor of obesity, it is still not perfect because of different reasons. 

We must be clear that BMI does not measure any health state of the body. Nor it is a confirmation test for presence or absence of a disease. In fact, there is a term called obesity paradox. There are actually people who live longer when their BMI remained on the higher side. (4)

Another study has found that nearly half of the people with higher BMI had a normal cardiovascular profile like normal BP, blood sugar level and cholesterol. On the other hand, about a third of the people had abnormal cardiovascular profile, though their BMI measurement was within healthy range. (5)

It is an excellent rough indicator of a healthy weight. Yet it is not accurate in case you are a muscle builder because your body weight will be more but it will be healthy type of muscle mass. BMI does not distinguish between muscle and fat. So, its reading is not reliable for athletes and muscle builders. 

It doesn’t measure the actual fats in the body. You might have a lower BMI but still your body fat percentage might be higher than normal. For example, it is known that Asians have higher fat percentage than whites and blacks. And whites have higher body fat percentage than blacks. BMI will not take this genetic difference into account. 

BMI also doesn’t consider waist circumference which is a good indicator of health risks. Belly fat is the worst kind of body fat and carries the highest risk. Therefore, waist to hip ratio is a better predictor of cardiovascular disease. 

It is also not an excellent tool for measuring obesity in kids and older people. The normal equation has to be modified for children and older people obesity. And of course BMI is not applicable for pregnant women.

But despite all these limitations, BMI is an excellent and easy screening tool as a measure of healthy weight for further tests and risks of heart disease. In fact, it is an excellent predictor of future obesity and overweight which are clearly linked with heart disease, diabetes, higher cholesterol levels and even asthma. 

BMI Table