Artificial trans fat will have to disappear from the American diet, according to the U.S. Food and Drug Administration. The FDA on Tuesday ruled that trans fat is not "generally recognized as safe" for use in human food. The department gave food manufacturers three years to remove the partially hydrogenated oils, or PHOs, from their products. The companies can petition the FDA for a special permit to use it, but no PHOs can be added to human food unless otherwise approved by the FDA. Eating a diet rich in trans fat is linked to higher body weight, heart disease and...