One of my favorite things about the ob#sity epidemic,* is the way certain statistics get repeated so often, by so many sources, that eventually they just sort of bake into our collective subconscious as truth… even though most people using the stat have no idea where it came from. One of the best examples of this is the claim that “ob#sity kills 300,000 people per year!” You’ve heard doctors say it. You’ve heard diet companies say it. You’ve heard Jillian Michaels, America’s patron saint of weight stigma, say it A LOT on “The Biggest Loser.” But is it true?
Now that we live in a real pandemic, I decided to find out. Because we’ve had over 500,000 deaths from Covid in the past year. And even when we were at the 300,000 mark, that number was big enough that even if you didn’t personally know someone who has died, you likely knew people who lost friends or family. On a purely anecdotal level, I just don’t think the same is true for high body weight; we often invoke weight to explain a tragic loss (and make ourselves feel more removed from the situation) but we don’t often name it as the singular cause. So I decided to chase down the origin story of this number while researching the first chapter of my upcoming book, and guess what: It’s not true.
In 1993, a study by researchers in the United States Department of Health and Human Services titled “Actual Causes of Death in the United States” combed through mortality data from 1990—yes, just that one year—and attributed 300,000 American deaths to “diet and activity patterns.” The only contributor with a higher death toll was tobacco with 400,000 deaths; in contrast, firearms only accounted for 35,000 deaths and illicit drug use, 20,000 deaths.
“Diet and activity patterns” are important. And they can influence body weight. But they are not synonymous with weight. These researchers did not study weight.
Nevertheless, the media, as well as many in the scientific research community, decided to equate lifestyle with body size. “Ob#sity kills 300,000 people a year!” became a kind of battle cry. In 1994, former Surgeon General C. Everett Koop invoked the stat when he joined forces with then-First Lady Hillary Clinton to kick off their “Shape Up America” campaign. By 1998, the study’s authors were so fed up that they published a letter to the editor of the New England Journal of Medicine saying, “you […] cited our 1993 paper as claiming ‘that every year 300,000 deaths in the United States are caused by obesity.’ That is not what we claimed.”
But their research has continued to be misinterpreted and misreported for nearly 30 years. Other weight researchers have tried to get to a similar number; sometimes they come up with an even bigger one, sometimes they fall short. If you really want to geek out on the statistical math of it all, this 2004 paper by leading CDC researchers explains why it’s so hard to attribute deaths to body weight. They also take on some of the research that tried to, um, find a way for that 300,000 claim to be right after it turned out to be wrong. “We urge caution in the use of current estimates of the number of deaths attributable to obesity,” the CDC researchers conclude.
Does this mean that zero deaths are attributable to high body weight? Of course not. But the relationship between body size and life expectancy is complicated. That’s because weight is a physical trait, not a behavior. Yes, if your weight goes too low, you can die. But we also know now that folks with restrictive eating disorders in bigger bodies can be just as sick as their “underweight” counterparts. (Often they’re even sicker by the time they get treatment because nobody notices that their diet became a disorder, but that’s a story for another day.) So we know that it’s the behavior of dieting that harms health, just like the behavior of smoking or the behavior of shooting a gun.
But a small body weight isn’t always the result of dieting or disease, which is why not all thin people are sick or dying from starvation. We readily accept this nuance to the relationship between small body weights and health. It’s harder to wrap our heads around the fact that not all high body weights are the result of deviant or irresponsible behaviors. Some high body weights are the result of equally dangerous and more intractable social determinants of health, like poverty, lived experience of oppression, lack of affordable healthcare, etc. And some high body weights are just what they are, and not posing any added health risk to anyone. Weight may be a correlating symptom rather than the cause of death. It may even be entirely unrelated, until bias in weight research links these things together.
Here’s what we do know: Inflated statistics like “300,000 deaths per year!” harm much more than they help. They offer no solution, nuance or empathy for the many complicated reasons that body size and health interact. And they strongly imply blame, especially when they are used to sell a diet—because if you don’t go on the diet now you are somehow contributing to this huge societal problem.
You’re not. I promise. You are not causing the deaths of 300,000 people per year with your body size. And pretty much anytime someone makes a claim like that, you can be sure there is a scientist somewhere sadly shaking their head and muttering, “that is not what we claimed.”
*Here on Burnt Toast, where I get to make all the final copy editing decisions, I use that strategically placed hashtag when I write “ob#sity” in recognition of the fact that it’s now widely understood to be a derogatory term. As such, I actually try not to use it (or any other “o words” like ob#se and overw#ight) at all, unless I’m quoting someone who uses them, or discussing research, as in this post.