ok im gonna go out on alimb here and say that im the TPN expert ;0)...
smallgit, unfortunately your mistaken. TPN can make you gain weight if the correct formula is being used for your needs. as in if you and your dr WANT you to gain weight your TPN formula is adjusted to make that happen.
is TPN hard on your liver? depends on the formula. if your specific formula. (each person should have there own) depending on what you taking it for can harm your liver. BUT if your not on it long term most of thes damages will repair itself. the liver is amazing.
for instance in my formula there is barely any extra calories than the minimum they can do with the added sugars. we went to this formula last fall. since the change i have lost 15lbs. but also due to a loss of appetite. i simply cannot eat enough food or drink enough calories (soda my weakness) to keep a steady weight. so they may change it back. and im talking this was a small decrease maybe 300 cals per day.
TPN can be a wondefull thing you can pretty much just live on it alone. ( i know people who have been on TPN alone for many years.) i mean not even swallowing their own spit.
you can add lipids, or "fats" for the necessary fats to live thats the hardest on the liver, with me we have found that by my eating meats and fats all day long i can avoid it being added to my TPN. the best way to tell when your in the hospital, when your having TPN after surgery is if its yellow, its just vitamins and sugar, trace elemnets, etc. if its tan or there is a seperate bag or glass bottle thats white, thats the fats.
just and fyi, did you know the body cannot live without fats? eventually the body will die of cellular decay. the body needs fats and cholesterol to make cells .