The Truth About Fats

Bad Fats

Excessive intakes of these fats can elevate LDL (or "bad" cholesterol), upping your risk of heart disease. While eliminating all saturated fat isn't realistic (unless you are a vegan), eating lean cuts of meat and low-fat dairy will put you on the fast track to better health.

Food sources: Fatty cuts of meat, whole and 2 percent milk, whole cheese, butter, premium ice cream, poultry skin

• Choose lean meats and fish over fatty cuts.
• Order foods that are grilled or baked.
• Replace butter with oil on your rolls.
• Cook vegetarian meals from time to time.

Heating liquid oils to very high temperatures (in a process known as hydrogenation) creates trans fats. They are essentially unsaturated fats that have been converted into saturated fats. Because trans fats behave like saturated fats, avoid them. Starting in 2006, manufacturers will be required to list trans fats on food labels. But for now, you have to be a sleuth: If a label says "partially hydrogenated fats," the product contains trans fats.

Food sources: Processed foods like cookies, crackers, potato and tortilla chips, and margarines; fried fast foods

• "Just because something is trans-fat-free doesn't mean it's calorie-free," says Lisa Hark, PhD, RD, a leading nutrition educator. She is concerned about manufacturers' trend of putting "trans fat free" on the label.

Good Fats

When substituted for saturated fats, monounsaturated fats -- which make up a good deal of the Mediterranean diet -- can help lower heart disease by lowering LDL cholesterol and raising HDL (or "good") cholesterol. In other words, these are the kinds of fats you need to eat.

Food sources: Olive and canola oils; almonds; avocados; peanuts; almonds; peanut butter; sunflower seeds

• Use salad dressings made from olive or canola oil.
• Eat a handful of nuts every day. Keep one-ounce portions in baggies to limit your intake, says Hark.
• Though often scorned, mayo is not a bad guy. In fact, "it's a good source of healthy fats like mono- and polyunsaturated fats and it has a much lower saturated fat content than cheese," Hark says. Opt for lower-fat versions, when possible.

Named because of a chemical bond that falls in the number 3 position on the fatty food chain, these liquid fats help lower bad LDL cholesterol, raise good HDL cholesterol, lower triglycerides (a type of blood fat), and may reduce the risk of blood clots. They are a type of polyunsaturated fat, and they've been shown to help people with arthritis and heart disease.

Food sources: Fatty fish like salmon or mackerel, nuts, mayo, and vegetable oils

• Substitute fish twice a week for other protein sources that aren't as heart-healthy.

These polyunsaturated fats found in vegetable oils are not bad, but keep your intake in check. We get too many of these omega-6 fats in our diet and not enough of the omega-3s (like those found in fish oils). A guideline: Aim for getting no more than four times as many omega-6s as you do omega-3s.

Food sources: Corn oil, soybean oil, cottonseed oil, safflower oil

• Make or buy salad dressing with olive oil (bottled salad dressings are often soybean-oil based).
• Cook or bake with olive or canola oil.

Whatever you do, watch your fat intake. Too much of any kind of fat is harmful to your waist and wellness.

Originally published on LHJ.com, March 2005.