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No, Being Fat Won't Help You Live Longer

A decade or more of "obesity paradox" research is just plain wrong.

West Coast Surfer/picture alliance / moodboard/NewscomWest Coast Surfer/picture alliance / moodboard/NewscomFile another one under "health research too good to be true." After more than a decade of reports that extra weight could boost longevity and protect against death by heart disease, a new study casts doubt on this "obesity paradox."

The purported paradox first appeared in research on people diagnosed with heart disease. After a diagnosis, overweight and mildly obese individuals lived longer than their normal-weight counterparts, according to research funded by the federal government. In the hands of the health press, this became 1,000 headlines about how being overweight was actually good for your health.

Yet according to Northwestern University's Sadiya Khan, the real reason the data appeared to show this weighty benefit is that overweight patients were developing heart disease earlier in life than their normal-weight peers. Yes, they tended to live longer following a heart disease diagnosis—but that's only because they were getting heart disease years earlier than skinnier people did.

As the Pittsburgh Post-Gazette puts it, "one of the main effects of carrying around too much excess weight is that you get fewer years of disease-free life."

While the mildly overweight live about as long as their normal-weight peers, heavier folks spend more of those years in ill health. And extra weight is also associated with a greater risk of developing cardiovascular conditions in the first place, says the Khan study.

According to Khan's findings, published Wednesday in JAMA Cardiology:

  • 32 percent of men with a body mass index (BMI) in the normal range (between 18.5 and 24.9) suffered a heart attack, stroke, or congestive heart failure during their time in the study, compared to 37 percent of overweight men (defined as those with a BMI between 25 and 29.9), 47 percent of obese men (BMI between 30 and 39.9), and 65.4 percent of morbidly obese men (BMI 40 or above).
  • 21.5 percent of women with a normal BMI had a heart attack, stroke, or heart failure, compared to 27.9 percent of overweight women, 38.8 percent of obese women, and 47.6 percent of morbidly obese women

Khan's research relies on data from the Cardiovascular Disease Lifetime Risk Pooling Project, and it includes an analysis of medical information on 190,672 Americans, each of whom were followed for at least 10 years.

Overall, extra weight raised a middle-aged man's lifetime risk of heart problems by somewhere between 18 percent (for the overweight) and 98 percent (for the morbidly obese), relative to their normal-weight counterparts. For middle-aged women, being overweight meant a 42 percent higher chance of heart problems, while being obese raised the risk by 75 percent and being morbidly obese raised the risk by 80 percent.

All this prompts the question: How did previous researchers on this topic manage to get things so wrong?

One answer is that early studies on the topic usually looked only at the period of time following a heart-disease diagnosis or negative heart-related event rather than considering a longer time period. And while researchers themselves often weighed the impact of this limitation—as well as the limitations of using measures such as BMI as a biomarker in the first place, and the danger of putting too much stock in one particular health outcome, like developing heart disease, while ignoring others—the nuances rarely survived a study's translation to a mass audience. Hence headlines like "A few extra pounds may cut risk of early death," "Why being overweight means you live longer," and "Scientists now think that being overweight can protect your health."

But bad health reporting doesn't deserve all the blame. Plenty of the published studies on the "obesity paradox" simply weren't that good, reflecting a larger crisis of credibility in the scientific and academic publishing community—a credibility crisis that's all too often overlooked in our government's rush to push food regulations under the veneer of science. Recently, this led to nationally implemented school "smarter lunchroom" programs that were informed by a body of research found to have serious flaws. Indeed, some of the research may have been entirely fabricated.

The "obesity paradox" is also rooted in the government. It starts with the National Institutes of Health (NIH). In 2005, an NIH researcher named Katherine Flegal published an analysis of Centers for Disease Control and Prevention data on mortality and weight, following this up over the next decade with several more papers in a similar vein.

"A lot of people interpreted this as being the official statement of the U.S. government," Walter Willet, chair of the Harvard Department of Nutrition, told Nature. Willet has not been shy about criticizing Flegal's work, declaring to NPR in 2013 that it was "a pile of rubbish, and no one should waste their time reading it."

Recent research has debunked all sorts of aspects of the supposed paradox. Using data from more than 225,000 long-term study participants, a 2017 study in the Annals of Internal Medicine showed that greater BMI was associated with greater risk of death from all causes, and a greater risk of dying specifically from heart disease; the association held up across sexes and age groups. Another 2017 study showed no obesity paradox when looking at new cases of cardiovascular disease.

Some scientists raised questions about Flegal's research from the beginning. "Closer examination of [obesity paradox] studies raises important questions on the validity of the paradox," stated a paper published in the American Journal of Cardiology in 2006.

"There is compelling evidence that the obesity paradox is not a real biological finding at all but just sloppy science," Boston University professor Andrew Stokes told Vox in 2015.

Photo Credit: West Coast Surfer/picture alliance / moodboard/Newscom

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  • sarcasmic||

    I read somewhere that fatties, smokers, and alkies use fewer health care dollars over their lives because they die much earlier than their healthier counterparts who tend to live long enough to get diseases that are much more expensive to treat, like cancer.

  • CE||

    There was another study out last week that having 2 drinks (of beer or wine) a day and being slightly overweight boosted your chances of living to 90 than working out every day did. The problem is the government guidelines for BMI are too low. Being skinny is very dangerous when you get older, because you don't have the reserves to survive a severe illness.

  • Chipper Morning Baculum||

    Wut.

  • DiegoF||

    They do. So do biker dudes who won't wear helmets.

  • BYODB||

    Never trust health reporting that defies common sense.

  • CE||

    Which is pretty much all of it.

  • DiegoF||

    Beware of Greeks bearing gifts of baklava and calling it a "Mediterranean diet."

  • Microaggressor||

    Never trust health reporting that defies common sense.

  • Greg F||

    Never trust a journalist that writes an article based on what another journalist wrote about another article.

    In graphical form:

    Original Study --> journalist 1 making a mess --> journalist 2 making bigger mess

  • Mongo||

    Your mama's so fat I gave her AIDS.

  • DiegoF||

    #BestSnapEverFTW.

  • Don't look at me.||

    The science is settled.

  • Marcus Aurelius||

    It is known.

  • Diane Reynolds (Paul.)||

    It'll help you during the zombie apocalypse.

  • Brian||

    Well, the science is settled.

  • Chipper Morning Baculum||

    Brian's dates hardest hit.

  • Citizen X - #6||

    Speaking of settling!

  • Marcus Aurelius||

  • Fist of Etiquette||

    Why did I have to read to the almost halfway mark of this article before the science of the BMI was introduced? It's the cornerstone of any health discussion.

  • Voros McCracken||

    There is no science to BMI. "weight squared divided by height" is not a scientifically arrived at figure.

    Most Olympic gold medalists are significantly overweight. Waist measurement is a far more significant indicator (and still deeply flawed).

    What we really want is 'lean body mass percentage' but that's a lot more difficult (IE expensive) and saw they just bullshit people with BMI, making it sound all mathy and scientific.

  • The Laissez-Ferret||

    ^This X 1000. BMI can helpful for people who don't exercise and eat a typical diet but should never be used for a guideline, especially when it comes to health and life insurance. I eat right and work out five days a week but according to BMI I'm overweight.

  • Fist of Etiquette||

    And out come the science deniers, right on cue.

  • ipsquire||

    I'm on the verge of BMI obese, my calcium score is 0 (at 50+ YOA) and my DEXA-measured bodyfat is under 20%. I'm in denial?

  • Marcus Aurelius||

    It's not just a river in Egypt

  • Marcus Aurelius||

    You don't have to be an Olympic athlete. I'd guess 75% of non-distance based competitive athletes. 5'10" & 180 makes you overweight. Your lucky to make a college football or basketball team at that size. Any guy who lifts regularly. So it I'd probably true that a good portion of the overweight males are healthier. BMI is a joke.

  • Mickey Rat||

    Well, until the next study comes along anyway.

  • Libertymike||

    Tommy Lasorda is 90 years old. He may not be all there, but his gut is.

    Seems like all the pasta and pizza hasn't hurt his march into longevity.

  • DiegoF||

    What happened to the Ultra Slim-Fast Plan?

  • Libertymike||

    Good point - the yo-yo and up and down stuff hasn't stopped him from reaching 90. You know damn well that he must have started a million diets only to be derailed by the smell of fresh pasta or pizza.

  • Marcus Aurelius||

    Cash is the great equalizer.

  • DiegoF||

  • Tony||

    So this guy who researched google searches concludes that straight men are actually more attracted to slightly heavier women but prefer to partner with rail-thin women in order to impress other people. Does this match anyone's experience?

  • Microaggressor||

    No. Too thin can make her infertile and not attractive.

  • Marcus Aurelius||

    That bald chick from Dr. Strange, you mean?

  • Adrian Willson||

    Well said being fat only brings problems to your body, diseases like heart problem , varicose veins, diabetes, knee pain are more prone to the fat guy, rather than the person who is physically fit.

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