I had the DS 11+ years ago. Could you tell me if your surgeon will she be performing the full DS or the SADI/SIPS? They are different things.
I can only speak to the full DS. I take 40+ vits/minerals per day. I have bloods done 2x year (some practices only require 1x year). I eat 125+ grams of protein per day. All of this is due to the malabsorptive component of the DS. While it helps keep the weight off, it requires you to be diligent regarding your protein and vits/minerals.
I also take probiotics each day. This is to help with gut bacteria.
I don't eat carbs or junk in public as this can lead to foul smelling gas & stool. I am careful to eat those in private and carry this to go in a public bathroom and a small vial of spray perfume to spray my butt if I have gas (which as I said isn't often in public bc of how I eat in public).
If you decide to have a DS, it's a good idea to have a Dexa bone density scan - preop. This will give you a good baseline. Also, keep all your lab and blood reports. You need to stay on top of your numbers bc while the surgeon's offices are helpful, sometimes they won't see a change as clearly as you will. I have some DS friends who have made Excel spreadsheets. I haven't; but I have all my bloods from preop on and study the last few each time I have a blood draw to compare where I am.
So, as you can see, the DS is a surgery where it's helpful to be organized and proactive.
That being said, I eat protein every 2-3 hours, never count calories, and never feel deprived (bc I can always be eating).