Oct. 13, 2010 — Nutrition rating systems and symbols on the fronts of food packaging would be most useful to shoppers if they highlighted four nutrients of greatest concern – calories, saturated fat, trans fat, and sodium – says a new report from the Institute of Medicine. These food components are routinely overconsumed and associated most strongly with diet-related health problems affecting many Americans, including obesity, heart disease, high blood pressure, Type 2 diabetes, and certain types of cancer.