Three years ago I was covered in P and 8 stone overweight. I did the cambridge diet for 6 months and lost 7 stone. Also my P COMPLETLEY DISAPEARED VERY QUICKLY. A year later I have put back all the weight and am now covered in P again, but I think this goes to show that diet plays a very big part in P. On the C. diet I had just 3 milkshakes a day, roughly 450 calories.