That old saw “you are what you eat” reflects an oversimplified view of nutrition. The notion that your body is a passive receptacle and its composition directly reflects what’s put into it is a logical assumption. In cooking, to make something sweeter you just add sugar; to make it saltier you add salt. But the human body doesn’t work that way. It can transform one constituent into another. It can turn sugar into fat, fat into sugar, and either into cholesterol. In fact, most of what you eat is turned into something else. You can’t, for example, just measure the level of cholesterol in your blood, reduce your cholesterol intake and count on the level falling accordingly. The body makes about three times as much cholesterol as you eat. If you consume less, it just makes more. It manufactures cholesterol out of sugar, starch, fat-- whatever is available. Perhaps it was this natural tendency to assume that body composition directly reflects what’s put into it that caused the world of nutrition to be turned topsy-turvy by the recent discovery of insulin resistance.