Overview
Trans fat is made when manufacturers hydrogenate (add hydrogen to) vegetable oil, which is, essentially, fat that has been extracted from the seeds in plants. Hydrogenation increases the shelf life and flavor stability of foods containing these fats. You should keep trans fats to a minimum. They have no health benefits. And like saturated fat and dietary cholesterol, trans fats raise LDL cholesterol, which increases your risk for coronary heart disease (CHD).
The U.S. Food and Drug Administration (FDA) estimates that the average daily intake of trans fat is about 5.8 grams, or 2.6 percent of calories per day for individuals 20 years of age and older. As yet, no "daily value" has been established by the FDA for trans fat consumption. On average, Americans consume approximately four to five times as much saturated fat as trans fat in their diet.
Characteristics of Trans Fats
Food manufacturers love that it’s cheap and easy to create trans fat by adding hydrogen to vegetable oil—a process called hydrogenation. Hydrogenation increases the shelf life and flavor of foods containing these fats. But trans fat raises the LDL cholesterol that increases the risk of heart disease. According to a nine-year study of 16,500 men published in the American Journal of Clinical Nutrition, researchers found that for every two percent increase in trans fat intake, men added 1/3of an inch to their waists over the course of the year.
Where to Find Trans Fats
Trans fat is found everywhere—in vegetable shortenings, some margarines, cookies, crackers, snack foods, and other foods made with or fried in partially hydrogenated oils. Unlike other fats, the majority of trans fat is formed when food manufacturers turn liquid oils into solid fats like shortening and hard margarine. A small amount of trans fat is found naturally, primarily in dairy products, but also in some meat and other animal-based foods.
Trans fats have been listed on all food labels since January 2006, but companies can say "no trans fat" if there is <0.5 grams of trans fat per serving, and when the serving size is small, that can ultimately create an issue.
How to Avoid Trans Fats
Try to limit the amount of vegetable shortenings, most margarine, crackers, candies, cookies, snack foods, fried foods, baked goods, and other processed foods made with partially hydrogenated vegetable oils.
- Check out the label for the amount of trans fats.
- Look at the ingredient listings and watch out for hydrogenated or partially hydrogenated oils.
- Look to see if the hydrogenated oil is in the first three or four ingredients. Because ingredients are listed in descending order of their occurrence in any product, this generally means there is a lot of it in the product and you will want to avoid it.
Another trick food manufacturers use is to separate the components of the food (such as coating and the filling). They can take up a majority of the ingredient listing with a full description of the first component and its ingredients, such as the inside filling of the food item, thus "hiding" the second ingredient, often hydrogenated fat, which appears later on in the product listing.
Don't be fooled by fast-food restaurants. Some have only recently switched from animal fat. The phrase "we cook in vegetable oil" can mean liquid or hydrogenated oil. Vegetable oil that is "cholesterol-free" can still raise your body's cholesterol if it is a hydrogenated or partly hydrogenated vegetable oil.
In general, if you try to choose the least processed forms of food, you will more than likely avoid trans fats. In most supermarkets, the easy way to do this is to stick to the perimeter of the store where the display cases back up against walls and, thus electricity, which keeps produce cool and fresh. The majority of the processed stuff is usually in the middle aisles.