Summarize:

Trans fat and saturated fat are the worst forms of fat, as they carry the highest risk of heart disease. Saturated fat is one of the biggest sources of cholesterol in many people's diets. Reducing or eliminating your intake of trans and saturated fats can help significantly reduce your cholesterol levels, when combined with other dietary and lifestyle changes.  Common sources of saturated fat include red meat, poultry, and full-fat dairy products.  Trans fat is found in some meat and dairy products, as well as baked goods, chips (potato, corn, and tortilla varieties), fried food, margarine, and some non-dairy creamer. Avoid foods labeled with "partially hydrogenated," as these are often high in trans fat.  Health experts recommend limiting your saturated fat consumption to 10 percent or less of your total caloric intake, but advise even lower levels (no more than seven percent of your total calories) to significantly reduce the risk of heart disease.  Trans fat intake should be kept as low as possible, as many doctors consider it one of the worst types of dietary fat in existence. Our bodies need some fat, and it's important to choose healthy types of fat instead of harmful forms. Healthier sources of fat include monounsaturated fat, polyunsaturated fat, and omega-3 fatty acids.  Good sources of monounsaturated and polyunsaturated fats include avocados, olive oil, safflower oil, peanut oil, and corn oil.  Common plant-based sources of omega-3 fatty acids include ground flaxseed, canola oil, soybean oil, walnuts, and sunflower seeds.  Fish is high in omega-3 fatty acids. Choose healthy fish like salmon, tuna, trout, mackerel, sardines, and herring. Certain high-fiber foods have been shown to be beneficial to the heart, and can even lower cholesterol levels when paired with other lifestyle changes. That's because soluble fiber reduces the absorption of cholesterol in the bloodstream, and can reduce your overall LDL ("bad") cholesterol levels.  Good sources of soluble fiber include oatmeal, oat bran, kidney beans, apples, pears, barley, and prunes.  Aim to eat at least five to ten grams of soluble fiber each day to help lower your total and LDL cholesterol. Sterols and stanols are naturally-occurring plant components that have been shown to help block the absorption of cholesterol in the body. Incorporating plant sterols and stanols into a heart-healthy diet can help reduce your cholesterol levels and lower your risk of heart disease.  Plant sterols can lower LDL cholesterol levels by five to fifteen percent, according to some studies.  Eat at least two grams of plant sterols/stanols each day to see results in your cholesterol.  Sterols are naturally occurring in all plants. Excellent sources of naturally-occurring plant sterols include vegetable oils, nuts/legumes, grains, cereals, and many leafy vegetables. Sterols/stanols are usually added as a fortified supplement to certain foods, including some types of margarine, orange juice, and yogurt drinks. Not every margarine or orange juice will be fortified, so check the label to confirm that a given product has added sterols/stanols. Whey is one of the two primary proteins in dairy products. Whey protein supplements have been shown to lower both LDL cholesterol and overall cholesterol levels. Whey protein powder is a common form of this supplement. You can find it at most health food stores and many grocery stores. Dosing will vary depending on the brand and formula you use, so it's best to follow the instructions on the package. Some studies suggest that a diet low in carbohydrates can help reduce the arterial accumulation of lipids, including cholesterol. Though more research is needed on the subject, it shows promising results in potentially preventing atherosclerosis in people with high cholesterol levels.  A heart-healthy low-carb diet should focus on lean protein sources, like poultry, fish, eggs, or tofu, as well as non-starchy vegetables.  Most low-carb diets limit daily carbohydrate consumption to roughly 60 to 130 grams.  Talk to your doctor about low-carb diets and other options before beginning any dietary plan. Studies have shown that plant-based diets, like those followed by vegetarians and vegans, can help lower LDL cholesterol and significantly reduce the risk of heart disease compared to meat-based diets. While many vegetarian- and vegan-friendly foods are still high in sugar and trans fat, a plant-based diet that incorporates fruits, vegetables, nuts, seeds, and vegetable oils is generally considered to be very heart healthy.
Cut out bad fat sources. Choose healthier fats. Eat high-fiber foods. Look for plant sterols or stanols. Take whey protein supplements. Lower your carb intake. Consider a plant-based diet.