Can you gain weight by feeding ensure

My dad recently had a nj feeding tube.  He doesn't feel hunger and we have been giving him 3 feedings of ensure a day.  He still looks like he is getting weaker.  The home health nurse that sees him says that on the days that he doesn't eat much by mouth (only soft or liquid food because of the tube going down his throat) to give him 4 cans of ensure.  do any of you know people that have actually gained weight using ensure feeding.  He needs sto get some strength back in order to begin chemo.  When the weather is nice I take him for a walk for exercise but we are going thru a rainy, snowy winter in wv right now.  I would appreciate any advice you have to give me.  He is the only father that I have.

Hi

Yes Ensure put 4 lbs on my husband in a week. Oncologists told him to drink ensure to put weight on before he starts chemo He drank 2 a day.