Hola Chula, I'm pretty new as well. I looked at your profile and we match pretty close. My surgery date is on 9/30 and I have to do THREE weeks of pre-op diet.
The Protein drinks are hit and miss. Your doctor's office should provide you with the info for your pre-op diet. My doctor's office gave me a three week supply of Bariatric Advantage. It's okay, not too bad. One suggestion I have for you is to definately get a blender and mix any drink up very good and drink it cold! It tastes much better that way! Good luck to you!