A lot of it is motivated by a search for easy answers: Eat too much butter, get fat. The answer should be "Eat less butter, move more." It is unsurprising that

A lot of it is motivated by a search for easy answers: Eat too much butter, get fat. The answer should be "Eat less butter, move more." It is unsurprising that "Eat margarine instead" is the wrong answer. Not everything about traditional food is good. Cured meats, for example. But a too-convenient solution is often too convenient to be true.