BMI means body mass index and is widely used by health practitioners (and insurance companies) all over the world to estimate how healthy someone is. It takes into account the height and weight of the patients and this ratio is used to categorize patients as normal, underweight, overweight or obese.
However, recent studies have shown that BMI may not be as accurate as we thought when it comes to health indicator. Researchers from Perelman School of Medicine, University of Pennsylvania have found that since BMI does not take into account the muscle mass, body composition, bone density, racial and sex differences, it is not a very accurate biomarker and predictor of health and morbidity.
BMI is an exaggeration:
A professor of Numerical Analysis at Oxford University, Nick Trefethen, explains that BMI exaggerates fatness in tall people and thinness in short people. This is because BMI is a ratio of weight in kilograms and height in meter squared. Professor Trefethen believes that the height squared divides the weight too little in tall people—making them think they are fatter, and too much in short people—making them think they are thinner.
What is a better indicator then?
There are so many better health indicators out there than the BMI. A good example is the weight circumference that is a good predictor of type II diabetes, irrespective of the BMI. Medical Research Council (MRC), Epidemiology Unit, UK has reported weight circumference to be independently and strongly associated with diabetes, even after taking into account the BMI.
Another indicator that can predict health is body composition. Body composition takes into account the percentage of fat in the body, combined with the weight. It is a better indicator of predicting disease and morbidity than BMI alone. However, it is not easily accessible or easy to do for everyone.
Flaw in BMI calculation:
Another flaw in the BMI calculation is that it does not take into consideration the lean muscle mass of the body. This means that because muscle is heavier than fat, BMI would cast muscular and athletic people in the overweight category, simply because of muscle weight.
This is very misleading for the patients and health practitioners as well because lean muscle mass is healthy for the body and reduces the risk of sudden death, and cardiovascular diseases.
In conclusion, BMI is a poor risk calculator and health indicator because it does not take into account the weight of bones, and muscles. Even though BMI is not completely without value, we should not just overestimate its importance.
There are other alternatives that are better health predictors, but some are very expensive and some are not accessible to everyone. For this reason, the Center for Disease Control, and the National Institute of Health continue to use BMI as a measure of health.
The bottom line is that obesity increases the risk of various diseases like stroke, heart attack and diabetes. If you want to reduce the risk of the aforementioned disease, then reach out to professionals who can help you reduce and manage your weight according to your age, and risk factors.