For decades, we considered saturated fat and cholesterol to be the demons in our diets when it came to heart disease. It was the message consistently presented by the American Heart Association (they still recommend limiting saturated fat). And it’s what the science pointed us to believe: cut down on saturated fat because it’s linked to an increased risk of heart disease. So what did we do? Replaced bacon with muffins, chose sugary cereals over buttered toast and eggs, and almost always went for the low-fat option—which usually meant more sugar in our diets.