Science Mom: ‘Fat’ Is Not The Opposite Of ‘Healthy’

Fat and healthy aren’t mutually exclusive. The idea that a person’s health can immediately be observed by a quick glance at the way they look is a pervasive one–and also a drastically wrong one. The all-encompassing focus on weight as the most important indicator of health, and the stifling atmosphere of fat-shaming around it, isn’t just foolish; it can also be dangerous–as many overweight people have found when trying to get medical attention for an illness, only to hear that their weight is the be-all, end-all of their problems. Forget busting calories; today we’re busting some big, fat myths.

Myth: Health and weight are inversely proportional.

Reality: You can be an overweight marathon runner. You can be a skinny Cheeto-and-Mountain-Dew addict. A person’s apparent weight has no direct relationship to their actual health, and unless you are Superman and can scan their internal organs and vital signs with a sweep of your X-ray vision, you can’t tell how healthy a person is just by looking at them.

In fact, some evidence suggests that focusing on weight loss can actually be harmful to an overweight person’s health by tying too much concern to how much weight they lose or keep off–and then making them relapse when the scale doesn’t budge despite their best efforts. Instead, better outcomes might be achievable focusing on “weight neutral” metrics. How’s your cholesterol? Are you eating enough fruits and vegetables? How many times did you exercise last week? These questions matter a lot more than How much do you weigh? Of course this is just anecdata, but my “sure, I can eat an entire carton of General Tso’s Chicken and then a dozen Oreos” college-aged body weighed 20 pounds less than my “I’m going to train my butt off and run 15 miles in a relay race” body. The version of me who stayed up till 2 AM playing Diablo II and binge-eating Goldfish crackers was not the healthier of the two, even if it did fit into a smaller jeans size.

And the focus on weight as an indicator of health is dangerous for thin people as well as healthy ones. I know a fat person who went to the doctor for a sore throat and left with a prescription to get more exercise instead of one for an actual antibiotic to treat her strep throat (which she got instead from a more helpful urgent care clinic). But how many of us also know or know of a thin person who suffered a heart attack out of the blue? Doctors often don’t think to monitor cardiovascular warning signs in a person who has the outward appearance we associate with health.

Myth: It’s as simple as calories in, calories out.

Reality: Even automobile engines don’t work this simply–the efficiency you get from your car depends on the temperature outside, the length of your drive, the type of traffic you’re driving it in, and many other factors besides how fast and far you’re driving it. Does it seem plausible that a mechanism as complex as the human body would somehow have a less complicated relationship with calories than a car engine would? Factors as far-ranging as the type of bacteria in your gut, the way your body produces hormones and regulates their levels, and the amount of sleep you’re able to get all have an effect on your body’s relationship with food, just as your diet and activity level do. Someone who ate and exercised exactly as much as you do might still end up weighing quite a bit more than you, or quite a bit less–so stop trying to act as if you can tell what someone ate for lunch or whether they hit the gym last night by eyeballing their waistline.

Myth: Skinny people live longer.

Very obese people do have higher rates of mortality than average-weight individuals. But guess what? So do underweight people. In fact, in a study comparing mortality rates among underweight, average-weight (referred to in the study as “normal weight”), overweight, and obese people, the group least likely to kick the bucket during the study was the “overweight” one.

Critics argue that the quality of life of overweight people is lower than that of those with average weight. Quality of life is certainly an important metric, but it’s easier to manage diabetes or heart disease in a living patient compared to the alternative.

Myth: Your BMI is an important and meaningful number for your health.

The BMI, or body mass index, was explicitly invented to compare large groups of people. It was never intended to be used as a judgment on whether or not an individual human being is a Skinny Minnie or a Fat Fatty Fatcake–and yet, chances are, your doctor’s office has your BMI recorded in your chart somewhere, and might even make prescriptions for your health based on those digits.

But your BMI doesn’t have any predictive value at all for your health. Yes, people who are obese have a high BMI, but a high BMI does not automatically mean you have a case of the OMGFATZ. You can be an athlete and have an “overweight” or “obese” BMI, because you know what’s extremely dense? Muscle. BMI also fails to take into account such characteristics as: having a pair of shoulders that wouldn’t look out of place on a linebacker. Giant knockers. Strong bones.

There are measurements that have predictive health value. You can measure your blood cholesterol, your blood glucose, your sodium titer. But those are lab tests, and lab tests cost money, which your insurance doesn’t want to pay for–why do fancy labwork when you can just shove someone on a scale and jot down their numbers? Well, because that fancy labwork actually has a lot more meaning for someone’s health, which is what a trip to the doctor is supposed to be about.

(Image: itVega / Shutterstock)