Trans fat: Avoid this cholesterol double whammy

When it comes to fat, trans fat is considered by some doctors to be the worst of them all because of its double-barreled impact on your cholesterol levels. Unlike other fats, trans fat — also called trans fatty acids — both raises your "bad" (LDL) cholesterol and lowers your "good" (HDL) cholesterol.

A high LDL cholesterol level in combination with a low HDL cholesterol level significantly increases your risk of heart disease, the leading killer of men and women. Learn more about trans fat and how to avoid it.

Reading food labels

How do you know whether food contains trans fat? Look for the words "partially hydrogenated" vegetable oil. That's another term for trans fat. The word "shortening" is also a clue: Shortening contains some trans fat.

It sounds counterintuitive, but "fully" hydrogenated oil doesn't contain trans fat. Unlike partially hydrogenated oil, the process used to make fully hydrogenated oil doesn't result in trans fatty acids. However, if the label says just "hydrogenated" vegetable oil, that usually means the oil contains trans fat.

Although small amounts of trans fat occur naturally in some meat and dairy products, it's the trans fats in processed foods that seem to be more harmful.

What should you eat?

Don't think a trans fat-free food is automatically good for you. Food manufacturers have begun substituting other ingredients for trans fat. However, some of these ingredients, such as tropical oils — coconut, palm kernel and palm oils — contain a lot of saturated fat. Saturated fat raises your LDL cholesterol. A healthy diet includes some fat, but there's a limit.

In a heart-healthy diet, 30 percent or less of your total daily calories can come from fat — but saturated fat should account for less than 7 percent of your total daily calories. Monounsaturated fat — found in olive, peanut and canola oils — is a healthier option. Nuts, fish and other foods containing unsaturated omega-3 fatty acids are other good choices.