In fact, we need fat in our diets for weight loss and normal bodily functions. There are four types of dietary fats: saturated fats, trans fats, monounsaturated fats, and polyunsaturated fats. It’s a bit more complex than saying all fat is bad for you. “Monounsaturated and polyunsaturated fats are known as the good fats,” says helpguide.org. Good fats are crucial for healthy cholesterol levels and heart health. You’ve probably heard some professedly, strange people say that eating fat is how they lost weight, well they’re on to something.