TRANS FATS AND FAT SUBSTITUTES

HYDROGENATION chemical process by which hydrogen molecules are added to unsaturated fatty acids

Most people who eat a Western diet—such as Americans and many Europeans—eat plenty of fat, just not necessarily the right kinds. Much of the fat we consume has undergone a process of hydrogenation, which makes unsaturated fats more solid and stable by chemically adding hydrogen to double bonds between carbon atoms on the fatty acid chain and thus makes them more saturated. This renders them harder at room temperature and more resistant to spoiling. This process can also improve taste, texture, and increase their culinary applications.

TRANS FATTY ACIDS fatty acids created by adding hydrogen to liquid vegetable oils (partial hydrogenation) to make them more solid; associated with an increased risk of chronic diseases, such as heart disease and cancer

One outcome of partial hydrogenation, however, is the structure of some of the unsaturated fatty acids can be converted from its natural “cis” configuration to another known as “trans.” These so-called trans fatty acids raise levels of ”bad” cholesterol, and lower levels of “good” cholesterol in blood, and increase the risk of heart disease more than any other type of fat. As little as 1% of total calories from trans fats can increase the risk of heart disease, stroke, or sudden death from these and other causes. Although a small amount of trans fat is naturally present in full-fat dairy products and beef, most of the trans fat we consume comes from the partially hydrogenated oils used to make processed foods that need a longer shelf life. The majority of trans fats in the U.S. diet are found in commercial baked goods (cakes, cookies, pies, biscuits, and doughnuts), packaged snacks such as crackers and popcorn, margarine, frozen pizzas, and fried potatoes. Given the risks of trans fats, as of 2006, all Nutrition Facts Panels must include the trans fat content of food products and more recently, the U.S. Food and Drug Administration has proposed a ban on their addition to any food products.

When purchasing processed foods, it is important to look beyond the grams of trans fat listed on the nutrition facts panel because foods with less than half a gram per serving can claim 0 grams trans fat. To minimize your intake of trans fats, avoid purchasing foods that list partially hydrogenated oils in the list of ingredients. Increasing awareness of the dangers of trans fats has resulted in more frequent use of fully hydrogenated oils. When oils are fully hydrogenated all double bonds are eliminated and no trans fats are produced. (INFOGRAPHIC 6.9)

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INFOGRAPHIC 6.9 The AMDR for total fat is 20% to 35% of our total calories and most of those calories should come from unsaturated fats.

Question 6.9

What parts of Nutrition Facts panel can help you to reduce your intake of saturated fat and trans fat? How can it help you identify unsaturated fat content? How can a food label help you understand whether a food product is within the AMDR range for fat?

The ingredients list on a food label can tell you whether a food contains small amounts of trans fats. Look for the words "partially hydrogenated oil" on the label.

In addition, sources of saturated fat are listed in the food ingredients. Hydrogenated oils as well as tropical oils such as coconut, palm, and palm kernel oils are sources of saturated fats.

You can check the total fat content of a food in grams and subtract the saturated and trans fat grams to calculate unsaturated fat content in grams.

A food label can help you understand whether that food is within the AMDR range for fat by doing a simple calculation. Divide the fat calories shown on the label by total calories and multiply by 100 to obtain a percentage. This percentage is the percentage of calories provided by fat--35% is the AMDR upper range for fat.