The main source of trans fats in the American diet is processed or packaged foods.
Although a small amount of trans fat occurs naturally in foods, most are liquid fats that have been turned into solids through a chemical process known as hydrogenation. Consuming trans fat has been proven to raise blood lipids, promote inflammation and cause blood vessel abnormalities that increase chances of developing heart disease and other chronic conditions. The Dietary Guidelines for Americans and the Institute of Health recommend avoiding all trans fats as much as possible; therefore, any food containing more than 0.5 gram per serving can be considered high in trans fat.
Stick Margarines and Vegetable Shortening
The trans fat in margarine and shortening allows the products to stay solid at room temperature. Margarine was created as an alternative to butter to decrease the amount of saturated fat in the standard diet. Saturated fat is known to increase the levels of unhealthy cholesterol in our blood, known as LDL. However, the trans fat in margarine not only increases LDL cholesterol but also lowers good cholesterol, HDL.
Commercial Baked Goods
Commercial baked goods such as packaged snack cakes, cookies, breads, muffins and pies often contain shortening or partially hydrogenated oils, laden with trans fats. Solid trans fats are more stable than liquid fats, allowing manufacturers to keep products on shelves longer without compromising flavor. Refrigerated dough products like pizza dough, cinnamon rolls and biscuits can also contain trans fat.
Milk, milk products and meat contain naturally occurring trans fats that are produced in the stomachs of grazing animals such as cows, goats and sheep. There is no known association between an increase in heart disease or arteriosclerosis with these naturally occurring fats, unlike the positive association seen with man-made trans fats, according to a study published in 2011 in "Advances in Nutrition."
The good news is that some restaurant chains have stopped frying food in hydrogenated oils and have made attempts to cut down on the trans fats in their products. However, many others have been slow to adopt healthier alternatives. French fries, chicken nuggets, crispy chicken or fish and even burgers can contain trans fats.
Cake Mixes and Frostings
Packaged cake mixes and icings often contain trans fats to increase their shelf life. Also beware of boxed pancake, waffle, muffin and biscuit mixes.
Frozen pizza crusts, frozen dinners, hash browns, French fries and chicken nuggets are notoriously high in trans fats. Check the label for trans-fat-free products when selecting frozen foods.
Potato chips, cheese curls, crackers, microwave popcorn and candy often contain trans fats. However, some manufacturers have made the move to eliminate all trans fats from their products.
Toppings and Dips
Check the labels of whipped toppings, salad dressings, gravy mixes and bean dips for trans fats. When dining out, skip the creamy dressings and whipped toppings to avoid any unwanted trans fat.
Coffee Creamer and Drink Mixes
Liquid coffee creamers often contain partially hydrogenated oils, also known as trans fat. Powder creamers can contain trans fats as well to keep them on the shelves for months at a time. Some chocolate drink mixes -- powders and syrups -- also have trans fat.
Some breakfast bars and cereals marketed as a healthy start to your day can contain hidden sources of trans fats. Steer clear of breakfast sandwiches served at fast food chains and packaged or frozen breakfast sandwiches, which can contain up to 3 grams of trans fat per sandwich.
Decreasing Trans Fat in Your Diet
Always check the nutrition label to determine the grams of trans fat in a serving, but be aware that foods containing less than 0.5 gram of trans fat per serving can still be labeled as trans fat-free.