I'm sorry, but people who say that eating fat makes you fat really dont know what they are talking about.
It's not eating the fat that makes you fat but eating fat combined with the massive volumes of carbs as well.
The human body was not designed to eat masses of refined carbohydrate, it was designed to eat primarily animal tissue and basic carbs like vegetables.
High doses of carbohydrate such as bread, potatoes and pasta cause massive insulin production, which causes the over production of glucose in the blood to be stored as fat.
High fat and protein diets, combined with low carbohydrate produce a state of Ketosis which means that your energy is being produced by burning fat, not blood sugar, (which means that the layer of fat under your skin is being taken away)
Its a much more natural diet, despite what the western protanagists of the food pyramid may tell you.
I went on this diet 18 months ago, and lost 3.5 stone.
...And I'm as fit a a butchers dog!