Heart disease is still the No. 1 cause of death for both men and women in America. But even if you already have heart disease or have had a heart attack, don't think it's too late for you to make some crucial changes that can greatly improve your health.

By lowering your LDL ("bad") cholesterol, you can actually slow, stop, or even reverse the build-up of plaque in your arteries. If you want to prevent heart disease, keep reading, because this plan will work for you too.

The National Heart, Lung and Blood Institute has begun a new program, called the Therapeutic Lifestyle Changes (TLC), which is composed of three parts: diet, physical activity, and weight management (of course). The TLC section guides you through several different "cyber rooms," each with interactive activities that will help you learn how to lower your blood cholesterol by making changes in your diet and activity level.

Here are the TLC program's diet recommendations:

• Saturated fat, less than 7 percent of your total calorie intake
• Cholesterol, less than 200 mg per day
• Soluble fiber, at least 10-25 grams per day 
• Plant stanols or sterols, 2 grams daily

Following all of these recommendations can lower your LDL cholesterol by 20 to 30 percent—as much as some medications can accomplish.

We've gotten used to thinking of trans fat as the villain, but did you know that saturated fat raises your cholesterol more than anything else in your diet? That's why the TLC program stipulates that saturated fat should not make up more than 7 percent of your total calorie intake. That means, for a 2,000-calorie diet, just 13 grams (about 117 calories) or less of saturated fat per day.

Saturated fat is in everything from ground beef to french fries to apple pie and its sources include meats, whole milk, cream, butter, and whole-milk cheeses plus coconut oil and palm oil. Choose products low in saturated fat—meaning those with 1 gram or less per serving—and start rooting out the saturated-fat sources in your diet.

Simple changes to your diet, such as adding more fruits and vegetables to your meals and snacks; thinking low-fat protein sources like legumes, chicken, and fish; and using low-fat dairy products, can boost your heart health.