Have you heard of the low carb diet? Dr Michael Moseley (the BBC doctor) calls his version the Blood Sugar Diet.
I lost 20 lbs, very easily, in two months using it. You basically reduce your carbs, eat more fat (but don't kick the arse out of it) and it forces your body to burn fat as fuel. Which includes your body fat.
It's great for endurance athletes too.
Fat isn't the bad-boy people used to think it was; that's sugar and highly refined carbs.