Going back to World War II again, we see this is where polyunsaturated fats started to become popular. According to “Good Calories, Bad Calories” by Gary Taubes, between 1945 and 1976 margarine consumption increased from four to nine pounds per American each year, salad and cooking oils from seven to 18 pounds. During the worst decades of the heart disease epidemic, vegetable fat consumption in the U.S. nearly doubled from 28 to 55 pounds.
