So the problem becomes that it's really hard to tell the difference between what is actual scientific consensus versus, say, a theory proposed by some random dude selling a cookbook. After all, it only took one high-profile "expert" to convince millions of people that ...

If you woke up tomorrow and decided to switch to a perfectly healthy diet, your first step would be to try to find out what that actually is. At that point you'll quickly find yourself in a shitstorm of conflicting information about what "science" says is good for you. The reason we haven't solved problems like obesity, heart disease, and diabetes is because there's still lots we don't know about how the body interacts with food.

5 Salt Causes High Blood Pressure

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The Misconception:

If you ask your parents (or maybe your grandparents, depending on how much of a whippersnapper you happen to be), there was once a time when salt was a glorious thing, enjoyed by the masses in wondrous abandon. If you went out to a nice restaurant, your entree was salt with a side of steak, and your dessert was a pack of unfiltered Camels. It was truly a magical era.

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"And a double martini to drink. Diet, please."

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Then, sometime in the latter part of the 20th century, that all changed. Suddenly, science figured out that salt was a crystalline boogeyman stiffening our arteries and causing our blood pressure to rise to literally vein-popping levels. Dinner would never be the same, and it was all based on some pretty flimsy-ass science.

The Guy You Can Thank for It:

Lewis Dahl.

The suggestion of a possible link between salt and high blood pressure had been floating around since 1904, but the theory didn't really hit the mainstream until the 1970s, when Dahl from Brookhaven National Laboratory announced that he had discovered "unequivocal" evidence that salt caused hypertension. What exactly was said unequivocal evidence? Pretty simple, really: by giving some rats a daily dose of salt, he had induced high blood pressure.

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His results were called into question when it was discovered the rats had also been participating in online political debates.

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By 1976, the president of Tufts University, Jean Mayer, was labeling salt "the most dangerous food additive of all." The U.S. Senate was recommending that Americans reduce the salt in their diets by as much as 85 percent. The New York Times was blaming salt for "high blood pressure, heart and kidney disease, and stroke." Salt apparently wasn't satisfied with some measly high blood pressure -- it had become food evil incarnate, haunting our entire freaking anatomy.