Diet: Is fat bad?

For a long time we were bombarded by the idea that fat is bad. With the little knowledge I possessed this never made sense to me. I was taught at school that we need fat to process a number of vital functions in our bodies.
Recently Dr. Tim Noakes switched to a protein rich diet generally associated with fats. He lost weight and is healthier now that a few years back. and
This morning I read an article about how being overweight is not necessarily bad.