Glenn Reynolds calls for conservative lawfare
This construction is revealing

One of the most effective propaganda campaigns ever

I speak of the alleged harm of saturated fat. The harm I refer to is not that fat is, ounce for ounce, more caloric than either carbohydrates or protein. I mean the allegation virtually all Americans seem to believe--really, really believe--that saturated fat does terrible things to your circulatory system. How many times have you heard people say, or have you read someone writing, that a dish like a chili cheeseburger with bacon is an "artery-clogger" or is "a heart attack on a plate"?

As Milton Friedman used to ask so energetically: How do you know?

The original research was, apparently, very dubious. (See also this.) And informed opinion currently rejects the claim. Related: the advice we got to eat a lot of bread wasn't so good, either.

Bottom line: too many calories seems to be bad for you and fat has more than twice as many calories per gram as carbs and protein. But beyond that, enjoy your fat, saturated or otherwise. (Except, of course, for transfat. But that's another post.)