I thought I'd give a quick update as I'm a year out from my gastric sleeve surgery 
I've lost 42 pounds and I'm now a very normal (still overweight but not really looking it) size 14.
I have much less arthritic pain - I bound up stairs, run to catch buses in a way that I could only shuffle (and cry!) a year ago. A year ago I cried with pain climbing stairs, every step a shooting pain through my hips.
I have not 'dieted' since the day I had the surgery. I don't count calories, I don't monitor what I'm eating at all - this is something I had been doing for 30 years ! before the surgery.
My weight loss is very VERY slow - which is a good thing as my skin has sprung back.
I've only lost 6 pounds in the last 5 months. Since the day I had the surgery I have NEVER put on weight - my weight has only gone down (I only weigh every 2 weeks).
For the purpose of this post only (as it's a year) I've counted my calories over the last week - they are about 800-1200 a day.
This is exactly what I expected and wanted.
Before surgery I had dieted for 2 years and ate 1500 calories a day (and was absolutely starving every day and it was utterly MISERABLE)
Now I just eat what I want (chocolate and crisps when I was just never able to have them because of dieting) and let my smaller stomach do the work.
Yesterday I ate:
One slice toast and marmalade
2 meals of veg pasta - 6 pieces of stuffed pasta per meal (in an 8 veg sauce)
One large gin and tonic
2 bags Wotsits 
6 pieces of Lindt hazelnut
At no point did I say to myself I can't eat more chocolate or crisps or pasta or gin. I just ate what I wanted.
I also took supplements- collagen drink/vitamins etc
The only thing that ever mattered to me was not living in pain and not dieting - I don't care if I stay a 14 (overweight) or end up an 8. I'm happy with my ability to walk, run, be comfortable in clothes NOW - any other weight loss is a bonus and makes walking even easier.
The only issue I've got is a personal one - I've not been able to go to the gym as work is too busy (this will change in January)
No idea if that will help anyone but if you don't burn many calories (and I'm not tall) then gastric sleeve can still work for you even if it takes a loooooong time to lose weight and weight loss is slow.