Why Being Fat Doesn't Automatically Make You Unhealthy

The obesity epidemic in America is certainly no joke, causing people to freak out over what this means for their personal health, and how to keep it from stretching our already tight healthcare system to its breaking point. The latter is one of the reasons fat-shaming is so prevalent, since obesity is a disease you can see -- just take a quick look around virtually any public space, and you can make a snap judgment about who's healthy vs. who's on the fast track to heart disease and DEATH.

But can you really? While it’s pretty easy to spot an overweight person, that doesn’t necessarily mean he or she is unhealthy. There’s a lot more to the health equation than just the pounds on a scale. In fact, calculating BMI (the ratio of weight to height) might be complete bullshit, to put it scientifically.

“[Your BMI] doesn’t tell you your percent body fat, how much muscle mass you have, what your lean body mass is, where the fat is distributed,” Dr. Eduardo Grunvald, program director at UC San Diego's Weight Management Program, says. “Two people with the exact same BMI might have very different health risks.”

There's a lot of other stuff going on inside your body

Obviously, weight plays a role in a person's health, but it's not exactly a black-and-white issue. Some people can be 50lbs overweight and still run a marathon, while others at a perfectly normal weight get winded walking up a flight of stairs. It’s best to leave an official assessment up to doctors, who can perform a series of tests to more directly gauge overall health.

“Tests that are very useful to convey [health] risks [include] blood sugar, HDL levels, and elevated triglycerides or LDL (bad cholesterol),” says Dr. Caroline Cederquist, founder of the diet delivery program BistroMD. Performing a hemoglobin A1C test is a good indicator of of how your body is using glucose, she adds, as is a fasting insulin test, both of which can show indications of pre-diabetes. Although these complications are commonly associated with lifestyle, some people are more genetically predisposed to high blood sugar or bad cholesterol, despite being a normal weight.

Examining overweight patients also involves looking at two factors besides weight: one is metabolic risk, which refers to illnesses like type 2 diabetes, high blood pressure, and high cholesterol. The other is fat mass consequences, which are basically all the mechanical realities that come with gaining a bunch of weight (joint pain, sleep apnea, acid reflux, etc.). Basically, is a person so fat that it hurts their knees to walk, or prevents them from falling asleep? If neither of those issues is present, it’s safe to assume a patient is relatively healthy, despite his or her weight.

The opposite can also be true; someone who looks perfectly healthy and of an average weight externally could have serious metabolic complications raging on the inside. Other lifestyle factors play a major role in overall health as well, most of which you learned about before high school, like smoking, drug addiction, stress, and lack of sleep, to name a few.

Where weight is distributed is more important than how much

While being overweight may (sometimes, but not always) lead to health consequences down the road, where this fat is positioned is actually a bigger concern. Unfortunately, people don’t get to choose where they store fat as they gain it. That’s up to the lovely wild card that is genetics. For the lucky group who gains evenly throughout their bodies, they may be off the hook more than people who get it all in their midsection.

Since BMI is a little too simplistic, doctors instead rely on a waist circumference test to keep an eye on obesity and potential health complications. A waist circumference bigger than 40in for a man, and more than 35in for a woman, is associated with increased health risk, according to Dr. Cederquist.

“If your fat is deposited more in your abdomen, your belly, or around your organs, or around your blood vessels, that is the more dangerous fat, because that causes all the metabolic problems that lead to diabetes, that lead to heart disease,” Dr. Grunvald warns. People of Asian descent tend to be at higher risk of this dangerous visceral fat than others, he says, even if it's not so obvious aesthetically. And they can develop metabolic problems at a much lower fat mass than other ethnic groups, such as Caucasians and African Americans.

You can be overweight and still be “healthy,” and vice versa

While some internet trolls love to harass any overweight person they see on social media out of "concern," while hiding behind the pretext of health, Dr. Grunvald says there's no such thing as a pound threshold that, once hit, automatically sends you on a downward spiral toward poor health and chronic disease. It doesn't exist.

“There are some people who are 20, 30, 40lbs overweight, who feel well, who don’t have the metabolic consequences, who are able to carry on with their lives, and be happy,” he says.

But there are everyday occurrences that could signal a decline in overall health, regardless of weight; Dr. Cederquist says not being able to get out of a chair, or gasping for breath after mild exertion are two major red flags, which probably should be obvious. The doctors also warned that continuing to gain weight could lead to future metabolic complications, and even if someone is "fat and fit," their lifespan is more likely to be cut short compared to someone of an average weight.

In the end, as long as someone maintains an active exercise regimen, eats healthy, whole foods, and avoids tobacco and chronic stress, he or she is already on the right track to maintaining a healthy lifestyle. It's not something that can be quantified on a scale or BMI chart, and is best left up to the pros to decide. The biggest lesson here is something you should've learned in preschool: don’t judge a book by its cover.

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Christina Stiehl is a Health writer for Thrillist who weighs less than Dwayne "The Rock" Johnson. Guess which one of them is healthier. Follow her on Twitter: @ChristinaStiehl.