It’s no surprise that scientific experts love to study chocolate: Not only does the average American eat over 10 pounds of the stuff annually, but we're pretty sure the researchers are sneaking samples between studies. Of course, this cocoa-flavored candy has also been shown time and again to be incredibly healthy for your heart. To determine the reason, a team from San Diego State University gave people either two ounces of dark chocolate (which contains high levels of antioxidant compounds called flavanols) or white chocolate (which doesn't have any flavanols) every day for a week. They discovered that those in the dark chocolate group had lower had lower blood sugar levels and LDL cholesterol (the "bad" kind) and higher HDL cholesterols (the good kind) than people who get the white chocolate. The higher the levels of cocoa in the chocolate, the better is for you, researchers believe, so be sure to grab a bar that's contains at least 70 percent. Remember, of course, that chocolate of any kind still contains fat and calories, so do your heart—and your midsection—a favor and stick to no more than an ounce or two per day.