I'll answer the low carb question in this post -- I did see a dietitian for guidance and she said she treated weightloss surgery patients. However, she still insisted on those government guidelines which caused me to put on a few lbs the first month with her so that didn't work.
I found (for myself) that I need to stay away from carbs, specifically bread. My diet consists mostly of a good protein and vegetable. For a carb, it's just a small portion of whatever carb I'm serving for that meal.
Example - instead of 2 pieces of toast for breakfast, I have 1 and I also look for thin-sliced grain bread which is healthier and less calories. As an evening snack, I'll have cottage cheese (Daisy is the tastiest) with pineapple or other fruit. The fruit becomes the carb (and low carb / calories).
You have to be careful with fruit because of the sugar but her body will tell her how much sugar she can handle. Too much and you get dumping....not fun.
At this point, I can pretty much eat anything I want except milk and ice cream (I can have a little DQ without getting sick) but I'm not much of an ice cream eater anyway. I just eat about half and I don't feel deprived and am much healthier.
I'd be happy to explain further what works for me so feel free to PM off-list and pick my brain.
I still consider myself a work-in-progress since I still need to lose another 40#. The doc said if I can't exercise enough, I won't get those last lbs. off but I'm not giving up, even if I can only lose 1 lb. a month, I'll get there eventually.
Sorry for rattling on and on but this surgery isn't for the faint of heart since we love our food.