dont eat anything but raw fruits and veggies and meet without stuff added till that day and drink a lot of tea with out sugar added.
So no bread, no dairy, no sugar beverages.
You will lose weight fast without any lactose or sugar. And do a ton of crunches.
Try to drink a glass of water every awake hour, this will keep you full.
I'm a very lightweight person... and even I lost like 6lbs in a few days when I switched my diet.