Snack Choices
Ingredient Concerns
Nutrition Questions
Health Professionals
For Your Health


Print this page

  1. What are trans fats?
  2. What are the sources of trans fat?
  3. Are trans fats harmful to me?
  4. How can I tell if trans fats are present in my food?
  5. Why do food manufacturers use partially hydrogenated oils?

Q. What are trans fats?
A. Trans fat is created when hydrogen molecules are added to unsaturated (liquid) oils during the process of “hydrogenation.” Hydrogenation causes some double bonds in fatty acid chains to take on “trans” configurations, which result in a more solid and stable fat. Trans fats are formed when vegetable oils are partially hydrogenated.

Q. What are the sources of trans fat?
A. Sources include foods and baked goods made with “partially hydrogenated vegetable oil” or some “vegetable shortening.”  Trans fatty acids also occur naturally in some animal products such as dairy products.   

Q. Are trans fats harmful to me?
A. In scientific studies, trans fats have been shown to raise blood levels of total cholesterol and the LDL cholesterol, the so-called “bad” cholesterol in the body and lower HDL, “good” cholesterol. Therefore, trans fat may increase the risk of coronary heart disease. Health experts recommend that intakes of trans fatty acid be kept as low as possible.

Q. How can I tell if trans fats are present in my food?
A. If the amount of trans fat is not on the Nutrition Facts Panel, the words “partially hydrogenated” in the ingredients list may indicate the presence of trans fat. However, the amount of trans fat in a product is highly variable and dependent on the degree of oil hydrogenation. Just because “partially hydrogenated” is listed in the ingredients, the consumer may not be able to determine how much trans fat is actually in the product.

  • Be aware that fully hydrogenated oils do not contain trans fat.
  • Ingredients in a food product are listed in descending order of predominance by weight, so when small amounts of partially hydrogenated oils are added to foods to improve blending and extend freshness, they appear near the end of the ingredients list (they contribute to very little or even no trans fat, per serving.).
  • For Frito-Lay products, you can refer to the nutrition panel since all Frito-Lay products are labeled with trans fat information.
  • Beginning January 1st, 2006, trans fat labeling is required on all Nutrition Facts Panels.

Q. Why do food manufacturers use partially hydrogenated oils?
A. Animal fats like lard, tallow and butter were predominantly used in the past for baking and frying foods. However, since scientists discovered the negative health effects of saturated fat in these foods, companies began to use partially hydrogenated oils instead. Partially hydrogenated oils provided comparable functional properties such as taste, texture, and stability and are also lower in saturated fat. In addition, partially hydrogenated oils are more shelf-stable and less likely to spoil, thus they provide products with longer shelf life. Evolving nutrition science now indicates that trans fats have a negative impact on chronic disease risk, and food companies are seeking alternatives to partially hydrogenated oils in order to reduce or eliminate trans fats.
Source: International Food Information Council