Maybe you've changed the kind of cooking oil you buy because some are healthier than others, or you've at least thought about it. But it's hard to keep up, since what's "good" for us changes with new research. When you heard that olive oil is better for you than generic vegetable oil, you switched, but then someone in your family was horrified that you weren't using canola oil instead. It makes a difference, since the average American gets 400 of their daily calories from cooking oil. Dietician Dana Hunnes helped Mel magazine rank cooking oils by the amount of various types of fat, so you can decide what to use. They also note that oils have different uses depending on how well they perform at high temperatures. Keep in mind that "every kind of cooking oil" does not include butter, lard, or bacon grease, because they just assume we know better.