Even though the ban's been set in motion, it'll take years before trans fat goes away completely. So it's up to you to know where it is, as well as how to distinguish it from other fat types. Trans is just one of many dietary fats, which vary significantly in how bad – or how good – they are for the body. While some kinds, like trans fat, are basically heart-harming garbage, other fats are very healthy, even necessary for the body to function properly – as long as you don't overindulge. But it isn't easy to differentiate between the many different types of fat. Here's your guide.