Since 2006, most food that you buy at a grocery store or convenience store is required to have a "Nutrition Facts" Label that will tell you how much trans fat is in a particular food item. These days, most packaged foods claim to have "0 grams trans fat." BUT, BEWARE! Federal law allows a food manufacturer to say that a food has "0 grams of trans fat" as long as one serving of the food item has less than 0.5 grams of trans fat.

So, if a serving size is, for example, one cookie, and the "Nutrition Facts" label says the cookie has "0 grams of trans fat" but the ingredients label contains the words "partially hydrogenated," then the cookie contains trans fat, perhaps as much as 0.49 grams per cookie. If you eat four of those cookies, you can quickly consume nearly 2 grams of trans fat!!

Remember, as little as 2 grams of trans fat per day has been found to substantially increase the risk of coronary heart disease.

Source: Mozaffarian, Dariush, Katan, Martijn B., Ascherio, Alberto, Stampfer, Meir J., Willett, Walter C.; Trans Fatty Acids and Cardiovascular Disease, N Engl J Med 2006 354: 1601-1613.