The So-Called Obesity Paradox

Oddly enough, some studies indicate that overweight people are more likely to survive cardiac events. But is the “obesity paradox” real?

There’s been a lot of excitement lately about the apparent “obesity paradox,” especially among people of a certain girth (Your Humble Author included). Basically, the paradox is this: a few studies have suggested that heavyset people are healthier than their lean counterparts.

The reason the medical community calls this a paradox is because it flies in the face of their expectations that fat people must naturally be less healthy than thin ones. Of course, doctors also used to think that using leeches was a Very Good Thing, and that illness was caused by bad vapours.


As nice as it would be to think that the doctors are wrong on this point (and who knows, they might be), modern medicine is a rigorous science that’s advancing by leaps and bounds. While the diagnostic arts remain a bit hit-and-miss, the practitioners tend to know what they’re talking about.

That said, according to some studies, individuals with a body mass index (BMI) of over 25 really are more likely than thinner people to survive cardiac events like congestive heart failure and stroke; and when they do survive, they live longer.

This holds true even when controlling for other factors, like smoking and existing illness. Which seems pretty suggestive, but…

Possible Explanations

Here’s the thing: this apparent paradox emerges from studies in which the researchers examined relatively small numbers of people; and even then, the heavier folks did better by only a few percentage points. It’s possible this is an artifact of the data, or researchers’ manipulation of it.

Even if it’s not, there’s no way to be sure there’s a true correlation between the two. After all, house fires and the presence of fire-trucks may correlate, but fire-trucks don’t cause fires. There could be something else in play that’s really upping the survival rate in obese people.

Other Possibilities

One problem is that in the studies, the researchers often diagnosed cardiac events from clinical symptoms, such as difficulty breathing and swollen extremities, rather than lab tests. In other words, some of the “cardiac events” might not have been real ones.

Furthermore, some doctors argue that the obese are more likely to present with cardiac symptoms earlier, and that health care professionals often treat those symptoms more aggressively as a result.


Even if obesity gives you a slightly greater chance of surviving a heart attack, we do know that it puts a strain on all the body’s systems (especially the circulatory and skeletal systems). You’re also much likelier to contract Type II diabetes, among other things, if you’re overweight.

So don’t ditch that diet yet. Until we’re sure the obesity paradox is real, it’s better to try to keep your weight down.