Instructions
Potions
Download the Knothole Island downloadable content from Xbox Live.
Travel to Knothole Island by going to Borrowstone, getting on the submarine and talking to the boat driver.
The boat driver will give you a care package containing a slimming potion.
Drink the potion by going into your inventory, selecting the potion and by pressing the "A" button.
Diet
Eat less food. This seems like a simple step, but it really works. Feed your character less food than you have been.
Eat food that has a negative fat percentage. For example, celery has a negative five fat percentage. You can get these healthy foods at produce traders and general traders. To see the fat percentage, take a look at the food's info list by selecting the item and pressing left or right on your joystick.
Have your character exercise. Active characters use up their body weight, making them skinnier. To exercise your character, have him run a lot when you are questing or running errands.