As always, you should go by what your professionals tell you so if what I say goes against what they say then completely ignore me!!! This may sound like I am a know-it-all which is not the case, I am always learning something new and lots of it comes for all of you! That said, I have read numerous books written by health professionals from America where the gastric bypass has been done for much longer and done millions of times, they all stress the importance of high protein intake in the first 6-8 weeks post-surgery.
In order to prevent muscle loss & to aide healing the main source of nutrition needs to be protein. It is almost impossible to get 80+ grams per day during the liquid stage but if I had followed only my diet sheets during liquids I was lucky to get in 20grams!! I added protein drinks which boosted me up over 40grams. My dietician told me at 6 weeks that I had the healing & fitness of someone at 10-12 weeks so I know I did it right. This is my opinion and I wanted to share it with you but like I said you are better to follow your own professional advice.