What your BMI means
It’s helpful to step back and consider what your BMI is measuring and why it’s being measured in order to understand what it signifies.
BMI is a measurement of size that accounts for both your height and weight. I recall using charts in the past that required you to enter your height along the left side and then slide your finger to the right to view options for your “ideal weight” within the categories of small, medium, or big “frame” sizes.
These graphs were created using actuarial statistics, which life insurance firms use to calculate your likelihood of living into your senior years using information from thousands of people. These charts were difficult to use and left room for confusion over how to determine a person’s “frame size.”
Similar results are obtained by BMI, which expresses the correlation between height and weight as a single number independent of frame size. Although the BMI has been used as a health indicator for more than 200 years, its origins.
What’s a normal BMI?
A BMI of 18.5 to 25 is regarded normal; a BMI of 25 to 30 is considered overweight; and a BMI of greater than 30 is deemed obese. If a person’s BMI is under 18.5, they are regarded as being underweight.
BMI is not a perfect test, just like most indicators of health are not. For instance, results can be skewed by pregnancy or excessive muscle mass, and it might not be a reliable indicator of health in younger or older people. Why does BMI matter, then? Generally speaking, having a higher BMI increases your risk of contracting a number of diseases associated to being overweight, including as
- liver disease
- several types of cancer (such as those of the breast, colon, and prostate)
- high blood pressure (hypertension)
- high cholesterol
- sleep apnea.
Nearly three million people worldwide pass away each year as a result of being overweight or obese, according to the WHO. Additionally, regardless of any specific ailment, persons with high BMIs frequently report feeling better after losing extra weight, both physically and mentally.
Should we stop giving so much “weight” to BMI?
Maybe. According to research, a person’s metabolic health, which is related to how much fat they have and how it is distributed, is commonly misclassified by their BMI alone. Additionally, BMI may be particularly unreliable for older people, athletes, and pregnant women.
It shouldn’t surprise anyone that this is the case. The same is true for cholesterol, blood sugar, or blood pressure as a single metric, none of which are expected to be able to distinguish between cardiovascular health and sickness. Cardiovascular health is crucial, but it’s not the sole indicator of wellness! For instance, the study cited above did not take into account ailments like arthritis or liver illness that would be pertinent to a person with a high BMI. Furthermore, BMI might be better at forecasting future health than it is at predicting current health. In accordance with research like these and these, people who are overweight or obese and in good health are more likely to eventually acquire diabetes or other detrimental health effects.
The bottom line
BMI is unquestionably not a perfect indicator of health when used alone. However, it’s still a good place to start for serious conditions that are made more probable by being overweight or obese. I think it’s a good idea to be aware of your BMI. But it’s equally critical to be aware of its constraints.