I recently received a Becel newsletter (don’t ask) very excited to announce that “Being moderately overweight increases heart disease risk.” You won’t be terribly surprised to find that this description stretches the truth just at leeeetle.

The original study (Association of Overweight With Increased Risk of Coronary Heart Disease Partly Independent of Blood Pressure and Cholesterol Levels) is a meta-analysis of several other studies.

The analysis begins by showing an increased relative risk for coronary heart disease among fat people, after controlling for age, sex, smoking, and physical activity. There are several more risk factors for coronary heart disease, three of the biggies comprising what is popularly called “Metabolic Syndrome” — high blood pressure, high cholesterol, and high blood glucose. Then there’s also dietary intake and family history of heart disease. These additional factors, if not controlled for, could confound the results of the analysis by showing relationships between things that aren’t really related. You know, like how murder rates increase with sales of ice cream — when summer isn’t accounted for. And we won’t even go into confounders like oppression syndrome and publication bias.

In this study, the researchers looked at what happened when they controlled for two of the biggies: blood pressure and cholesterol. As a result, the fat people’s increased relative risk for heart disease was cut in half. And, stopping while they were still ahead, that’s where they decided to leave the matter.

See, now, if it were me, I’d be all: “Hey look, maybe we can reduce fat people’s risk of heart disease by treating high blood pressure and cholesterol! If we address high blood glucose and dietary intake, we might lower it even further!” And these risk factors are treatable with medications, or lifestyle interventions, or both — unlike fat, which, well…let’s just say if there were an effective treatment, the entire Western Hemisphere would be on it, and no one would ever be fat again.

But to the authors of the study, finding that controlling for only two major risk factors halves the increased risk, without controlling for blood glucose (which is considered by some to be the most important component of Metabolic Syndrome), somehow translates as “clearly, fat by itself increases risk of heart disease.” Come again?

This, despite the fact that the authors themselves cite another study that did exactly the same analysis, but for one detail: it also controlled for blood glucose. The result of that study? The increased relative risk of heart disease for fat people was eliminated entirely.