MANHATTAN, KANSAS — The Food and Drug Administration has announced that partially hydrogenated oils, which are the primary dietary source of trans fat, are not "generally recognized as safe" for use in food. This ruling comes two years after the FDA's first tentative determination of the same finding and a request for comments on the matter. The FDA has given the food industry until 2018 to stop using partially hydrogenated oils and fats in processed food products.

Mary Meck Higgins, a Kansas State University associate professor of human nutrition and an expert in food and nutrition, discusses what the announcement means for nutrition and the food industry.

Expert name: Mary Meck HigginsExpertise: Kansas State University associate professor of human nutrition, K-State Research and Extension specialist, fellow of the Academy of Nutrition and Dietetics, registered dietitian and licensed dietitianWebsite: http://www.he.k-state.edu/hn/people/faculty/higgins/

Comments/quotes:What is trans fat? "The primary dietary source of trans fat is partially hydrogenated oils. These oils are produced by a process called hydrogenation, where some hydrogen is added to a liquid vegetable oil, which converts it into a solid when it's at room temperature. Partially hydrogenated oils and fats, and thus artificial trans fat, have been in many processed foods for the past 60 years. They are used to improve the shelf life, texture and flavor stability of a processed food."

"Foods sold without a nutrition facts or ingredients label do not have partially hydrogenated oils or artificial trans fat in them. Small amounts — typically about 2 to 3 percent — of naturally occurring trans fat may be found in some cooking oils and in the fat component of dairy and meat products from ruminant animals, such as cattle, sheep and goats."

What does this announcement mean? "Food companies will have three years to stop using partially hydrogenated oils and fats in their processed food products. After that, there should no longer be artificial trans fat in our food supply."

Why is it important?"Eating partially hydrogenated oils and partially hydrogenated fats is a strong risk factor for getting heart disease, which is the No. 1 cause of death for men and women in the U.S. They contribute to the buildup of plaque inside the arteries that may cause a heart attack. Eliminating them from the food supply should prevent thousands of deadly heart attacks each year and fewer people will get heart disease."

"Currently, eliminating trans fat from one's diet entirely is all but impossible because it's practically unavoidable in the U.S. diet. People would also have to spend lots of time reading two kinds of food labels. The nutrition facts label shows how many grams of trans fat are in one serving of each processed food. In many instances though, a food that is made with partially hydrogenated oils has too little trans fat in it per serving to be listed on the nutrition facts label. For foods showing 0 grams trans fat, one must then look at the mostly small-print ingredients list. If a partially hydrogenated oil or fat is listed as an ingredient, then that food does contain a small amount of trans fat. The new FDA ruling will eliminate the need to have to do all of this, since partially hydrogenated oils will no longer be in our food supply once it goes into effect."

What else should we know about this announcement?"Food companies have three years to eliminate partially hydrogenated oils and fats from their products. Until then, check ingredient lists of foods — especially frozen pizzas, coffee creamers, stick margarines, microwave popcorn, crackers, cookies, refrigerated dough products, cakes, packaged pies, ready to use frostings and nutrition bars — and avoid those brands that contain partially hydrogenated oils and fats."

"To further reduce risk of heart disease, people should limit dietary saturated fats. On average, people living in the U.S. eat four to five times as much saturated fat as trans fat."

How can a person reduce dietary saturated fat? "Eat at least three one-ounce servings of whole grains and 4 1/2 cups of fruits and vegetables a day. Eat seafood — including oily fish — and cooked dry beans and peas in place of some meat and poultry. Choose skinless poultry. For beef and pork, choose lean cuts — such as loin — and at least 90 percent lean ground. Limit intake of fatty meats, such as sausage, franks, bacon and ribs. In addition, choose fat-free or low-fat milk, yogurt, cheeses and other dairy products. Cook and bake with liquid oils instead of shortenings, butter and lard."