What Is Trans Fat, Why Is It Bad For You, And How Do I Avoid It?

Question: What is trans fat, why is it bad for you, and how do I avoid it?

Answer: Trans fats are found either in an animal fat or in partially hydrogenated fat. What we've found is that diets that are higher in trans fat tend to raise your LDL cholesterol level. And higher LDL cholesterol levels are associated with increased risk of heart disease .

So in order to decrease your intake of trans fatty acids, the first thing to do is select products that are not made with partially hydrogenated fats. And the way to do that is either to look on a nutrient facts panel, or actually ask how the food is prepared. Partially hydrogenated fat tends to be things like shortening and solid vegetable fat.

The other sources of trans fatty acids, which is about 20 or 25 percent of which you're probably consuming, comes from animal fat. But because we also want you to decrease your saturated fat intake to decrease your risk of cardiovascular disease -- by choosing lean cuts of meat and low or non-fat dairy products -- then decrease your intake of both saturated and trans fatty acids from those sources.

Alice H. Lichtenstein, D.Sc., Director and Senior Scientist, Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging at Tufts UniversityPlay