Some companies already are doing just that. Frito-Lay, maker of Doritos and other popular snack foods, began listing trans fats on their product labels earlier this year. McDonald's has announced that it plans to stop using trans fats altogether in cooking its french fries. Last week, Kraft Foods, the leading food manufacturer in the nation, said it planned to reformulate many of its most popular products, which include Oreos, to reduce levels of trans fats. And yesterday, Unilever Bestfoods, maker of a leading seller, I Can't Believe It's Not Butter, said the margarine will be free of trans fats by 2004.

In 1999, when the FDA first proposed a labeling requirement for trans fats, the agency suggested lumping them with saturated fats. But FDA Commissioner Mark McClellan said yesterday that the National Academy of Sciences and other groups have concluded that there is insufficient scientific information to set a daily intake level for trans fats. "Clearly we need to do more research, since people's dietary choices have such an important impact on health," he said.

In the meantime, however, McClellan urged consumers to eat a minimum of trans fatty acids -- echoing recommendations from the National Academy, the National Heart, Lung, and Blood Institute and the American Heart Association. For someone consuming an average of 2,200 calories a day, the government recommends limiting saturated fats and trans fats to a combined total of no more than 20 grams per day. That is about the amount someone would get by eating a slice of apple pie (three grams from saturated fat, four from trans fats), a chocolate doughnut (about five grams of each) and a couple of Oreo cookies (about one gram of saturated fat, two of trans fats.)