The diet is according to your body and whatever you have conditions you havehave. It determines what type of diet that they give you

My suggestion is that you go to the doctor and they will give you 1

One can do a search online. I just checked. There are so many. Plus, I think may likely vary by the doctor or clinic, etc. and how much one weighs pre surgery, etc. Do you want a longer-term pre-surgery, short term pre-surgery, after surgery, Or ? Amazon also has lots of books for these diet plans. Here's a bit of information I came across. I never had weight loss surgery so sorry can't offer more help. https://www.obesitycoverage.com/the-big-gastric...

The Complete Gastric Bypass Diet Guide

https://www.obesitycoverage.com/the-big-gastric-bypass-diet-guide/

Some hospitals have a “ask a nurse” number too

Should be online. There’s a pre surgery, post surgery 30 day and rest of your life diet. Any Registered Dietician would have it.