When Skin is Cut off During a Body Lift, How Much is Fat and How Much is Lean Body Mass?

I know of no Plastic surgery colleague who bases the amount of excess skin and fat removal on a pre-set weight reduction goal. Nor do surgeons analyze the removed excess trunk skin and fat for their exact component parts. Many people who decide to change their life style by eating healthier and exercising become focused and driven in this goal. While it changes ther lives for the better it really does not help us as Plastic surgeons. When encountering people who underwent large volume weight losses we work with them on planning the best path for them to get rid of the excess skin reminding them of their long gone bodies and help bring out their new bodies by removing all excess skin. The weight of the skin, it's fat composition is immaterial. As a service to you, your surgeon surgeon surgeon would gladly weigh and photograph the skin and fat removed from you, if you so wish. 

When the excess skin is excised it includes all the fat attached to it down to the muscle. No "lean body mass" is removed.