If you're trying to sort out all the facts about good and bad cholesterol - and how it affects your body, cut it out! There's only one thing you need to know: Avoid saturated fats. Period. Why? According to MSNBC, eating just one meal a month that's high in saturated fat is instantly bad for your blood circulation. The Heart Research Institute in Sydney, Australia, fed volunteers carrot cake and a milkshake one month apart. The first batch of cake-and-shake was high in saturated fat from coconut oil. And the second was high in polyunsaturated fat from safflower oil. The result? Three hours after eating the saturated-fat cake-and-shake, the artery linings of the volunteers couldn't expand as easily to increase blood flow. The saturated fat also interfered with HDL - the "good" cholesterol that helps protect arteries from the inflammation that can lead to clogs, heart attacks, and strokes. After eating the cake and milkshake made from polyunsaturated fats, the arteries of the volunteers experienced an anti-inflammatory boost. In fact, fewer inflammatory agents were found in their arteries than before they ate. So, where do you find the saturated fats you should skip? Mostly in animal products, like beef, pork, poultry, butter, milk and cheese, and some plant-based oils, like coconut oil, palm oil, and cocoa butter. Try replacing them with polyunsaturated fats from plants, like safflower, sesame, sunflowers, corn, soybeans, and nuts.