They say 1 lb of fat is about 3500 calories. in two stone that would be 98'000 calories of fat. Assuming you need 2000 a day to survive that means you'd have to eat nothing and burn 84'000 in exercise over the week, being 12'000 calories of exercise per day, no food. You'd kill yourself or make yourself extremely ill if you tried to do this. If you're desperate, maybe try lypo suction?