Associated Press
    Fast-food chains have cut back on their use of trans fats. Above: french fries served in Southfield, Mich., in a February 2007 file photo. 


    What are trans fats, and why are they bad?


    Where do trans fats come from?

    Some of it is produced naturally in the stomach of grazing animals, and therefore present in small amounts in milk products and meat. But the main source is from vegetable oil that has been processed with hydrogen to make it more solid. Food makers use these artificial trans fats, known as partially hydrogenated oils, to improve texture and make products last longer.

    Where are they found?

    Trans fat has been used in many food products, particularly cookies, muffins, cakes, and other baked goods, as well as frostings. According to the FDA, it also is used in some snack foods (such as microwave popcorn), frozen pizza, vegetable shortenings, and coffee creamer.

     What’s been done about them before the ban announced Thursday?

    Trans fat became popular in part because of health concerns – vegetable oils were considered healthier than the saturated animal fats that were widely used. In the 1980s and 90s, researchers began linking trans fats to heart disease. In 2006, after much debate, the FDA began requiring food companies to put labels on foods containing trans fat. Before that, only consumers familiar with ingredients jargon like “partially hydrogenated vegetable oil” and “vegetable shortening” would have known that their foods contained trans fat. Some states and localities have also adopted regulations limiting the use of trans fat.

    Where have trans fats been pulled from?

    The FDA’s labeling requirement, and growing public concerns about the health risks of trans fat, prompted many big chains and food companies to stop using the stuff, or cut way back. Mondelez International , then part of Kraft, replaced it with non-hyrdogenated vegetable oil in its Oreo cookies in 2006. On its website, Mondelez says it has completed a multi-year effort “to eliminate or significantly reduce trans fats from our entire portfolio around the globe.” Fast food and other restaurants were once a big user of trans fat, but McDonald’s, Burger King , Starbucks and KFC all artificial dropped trans fats (Burger King and KFC still have small amounts in some menu items; a Burger King spokesman says some of its meat and dairy items have the naturally occurring trans fat). And Long John Silver’s has announced plans to switch all U.S. restaurants to trans-fat-free cooking oil. Church’s Chicken also expects to have all stores converted to trans-fat-free oils by Christmas.

    What foods still contain trans fat?

    Sara Lee cheesecakes, Betty Crocker cake mix, and Pop Secret popcorn all list partially hydrogenated oils in their ingredients.  The Center for Science in the Public Interest, which has been a leading crusader against trans fat, identifies some fast-food chains, including Popeye’s Louisiana Kitchen,  that still use trans fats in some products.

    Why are they still in foods?

    Hydrogenated oils are easy to use. They can withstand repeated heating without breaking down, and the process can turn liquid oil into solid, making for easier transportation and wider uses, according to Harvard School of Public Health’s Nutrition Source website. Hydrogenation also is relatively cheap—which explains why it continues to be widely used in many emerging and developing economies.



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