When you’re watching your weight, you’ll probably come across the term “BMI.” But, what does it exactly mean and does it matter when you’re trying to lose weight?
Your Body Mass Index or BMI calculates your height and weight. BMI calculators and charts are available online for you to see whether your BMI is in the healthy, underweight, overweight or obesity range.
A BMI of less than 18.5 is categorised as underweight and can sometimes indicate eating disorders. People in this range will need to adjust their diet to gain more nutrients. The normal range is a BMI of 18.5 to 24.9. The overweight range is a BMI of 25 to 30 with a vulnerability to hypertension, high triglyceride levels, diabetes, stroke and coronary heart disease. The obese range is a BMI of greater than 30, while the morbidly obese range is having a BMI of more than 40.
BMI has been critiqued for its inaccuracy, but it has proven to be useful in some cases, particularly when assessing a person’s risk of developing diabetes, arthritis, liver disease, high blood pressure (hypertension), high cholesterol, sleep apnea and some types of cancer (such as breast, colon and prostate)
BMI is considered by most medical professionals and researchers to be an arbitrary calculation. BMI does not accurately take into account one’s bone, muscle, water and fat mass. It also does not include other factors like one’s age, sex, blood pressure, triglycerides, cholesterol and insulin resistance. Overall health is not just about having weight that is proportionate to one’s height.
Since BMI overlooks bone and muscle mass, athletes will sometimes find themselves to be regarded as overweight. Athletes, who usually have a lot of muscle mass, are also commonly healthy and fit. BMI doesn’t distinguish this, though, and cannot be applied to fit individuals and athletes.
BMI also does not calculate fat percentage. Our body stores two kinds of fat–subcutaneous (under the skin) and visceral (around the organs). It is dangerous to have more visceral fat around the stomach and heart and can lead to heart diseases, stroke and diabetes. However, BMI cannot distinguish this. Even if two persons have the same BMI, their fat percentage will not be alike.
Age and gender as well as ethnicity also get overlooked by BMI. Older people should be wary of BMI, since they naturally lose height and muscle, but gain fat. Even though BMI doesn’t differentiate results for men and women, women tend to have more fat than men. Certain ethnicities also have more body fat, according to some research groups. Asians typically have a higher fat percentage than Caucasians and are more at risk of getting heart diseases and type 2 diabetes.
If you still want to make BMI your standard of choice for measuring a “healthy” weight, it’s important to know these things. Your BMI or weight may not change, but your body composition and physique can. Your BMI may remain the same or may not change much, but your body becomes fitter and healthier. For example, body fat can be displaced with muscles. Weight loss and fitness may not always be visible to the eye or on your scale. A fitter body and overall healthier body image rely on fat loss and muscle gain without necessarily going down the BMI scale.
