- Body mass index, or BMI, is determined by taking one’s weight in kilograms and dividing that number by the square of their height in meters.
- Many argue that BMI is inadequate in evaluating a person’s health as it ignores important factors such as family history, genetics, lifestyle, age, gender, and muscle mass.
- In fact, many people who are considered in the “normal” BMI range were found to be unhealthy based on other factors.
Body mass index, or BMI, is a calculation of height and weight that is used to screen people for obesity or being overweight and to help assess the risk of developing diseases such as type 2 diabetes or heart disease.
The formula for BMI – weight in kilograms divided by the square of height in meters, according to the Centres for Disease Control and Prevention (CDC) – was invented in the early 19th century by Belgian mathematician Lambert Adolphe Jacques Quetelet as an easy measurement of obesity in the general population and not necessarily for individual fatness, according to NPR. BMI, however, is still used regularly today by medical professionals to determine if a person has a healthy amount of body fat.
Though it can be useful in a general sense, BMI misses important factors such as family history, genetics, lifestyle, age, gender, and muscle mass when considering a person’s overall health and their risks of developing diseases.
“Not even the most qualified experts truly understand obesity,” weight loss specialist Chris Shuff, RDN, LDN told Healthline. “So patients certainly don’t. It’s an issue with millions of variables that’s so complex and winds through every facet of someone’s life.”
In fact, many people who are considered in the “normal” BMI range were found to be unhealthy based on other factors, a UCLA-led study released in 2016 found.
Here are seven signs that you’re actually healthy, even if your BMI says you’re overweight or obese. Just remember your health should be considered holistically and not based on any one factor alone.
Waist circumference might be the most important indicator of your health.
Business Insider reported that waist size may actually be one of the most important factors in measuring a person’s overall health. You may have a high BMI, but if the circumference of your waist is below 35 inches as a woman and 40 inches as a man, you’re more likely to have a healthier weight.
“A waist circumference greater than 35 inches in women and greater than 40 inches in men could not only determine overweight status but put a hard-and-fast number on one’s health,” dietician Michelle Routhenstein, MS, RD, CDE, CDN, told Healthline.
“Waist circumference above these numbers indicates excessive belly fat, a dangerous type of fat surrounding vital organs, which increases one’s risk of diabetes, high cholesterol, high blood pressure, and the metabolic syndrome,” she added.
Your body type can indicate if your body fat is “dangerous.”
Similarly, where your body stores fat is an indicator of your health.
“[BMI] also does not tell us the distribution of body fat in a person,” Eva Tseng, MD, MPH, an Assistant Professor of Medicine at Johns Hopkins, told PopSugar. “We know that people with more central or abdominal adiposity [obesity] have a higher risk of premature cardiovascular disease, diabetes, and death compared to people with a similar BMI but less abdominal adiposity.”
Fat that builds up around your waist and belly is more dangerous than the fat that gets stored around your thighs and hips.
Muscle mass can make you heavier and increase your BMI.
As Business Insider’s Erin Brodwin explained in a post,BMI doesn’t account for body composition, including differentiating between muscle mass and fat. Because muscles are more dense and heavier than fat, bodybuilders and other professional athletes like football players are often considered obese or overweight based on their BMI alone.
If you have high muscle composition, you’re probably not overweight or obese.
Metabolic tests can show if you have serious health problems because of your weight
Because BMI can’t holistically show a person’s health, indicators such as cholesterol, blood pressure, and blood sugar are good indicators of your health. Dr. Scott Kahan, the director of the National Center for Weight and Wellness, told WebMD that there are plenty of people who are overweight, but still healthy, even though their BMI would indicate otherwise.
“They’re heavy,” he said. “Their BMI puts them in the obesity range. And yet on every level that we look at, their health is actually quite good. Their cholesterol and blood pressure are excellent. Their blood sugar is excellent. They don’t seem to have any health effects associated with their excess weight.”
This is sometimes called metabolically healthy obesity, but not much is known about the long-term implications of being overweight or obese with a healthy metabolism.
If you’re generally fit and active with a higher BMI, you’re still healthier than skinny people who aren’t active
According to a 2007 study done on veterans with type 2 diabetes, a person’s level of fitness predicts their mortality better than BMI. So if you are generally fit and active, you’re going to be healthier than someone who isn’t, regardless of their BMI.
“It’s much more important to avoid low fitness than it is to avoid fatness,” cardiologist Carl Lavie MD, FACC, FACP, FCCP told Mother Jones.
Depending on your age, having a little extra weight can be healthy.
Dr. Richard Atkinson, a researcher and editor of the International Journal of Obesity, toldWebMD that older people who are slightly overweight tend to live longer than leaner elderly people, though the reasons for that are unknown.
“People who are older probably should have a little more fat on them, [but] they shouldn’t have a BMI of 30,” he said.
Your ethnicity can also affect your BMI.
Depending on your ethnicity, your BMI could be more unhealthy than you think.
Studies have shown that Asians have a greater risk of developing type 2 diabetes at a lower BMI and have a higher mortality risk for being overweight at a lower BMI. Conversely, African-Americans may have a higher BMI without the same health risks that a white person might have, according to WebMD.
Visit INSIDER’s homepage for more.