lightweight

Hi I am 5 2" and 200 pd I want to lose 70 pd which surgery would let me not lose to much weight 

I had RNY and my body stopped losing at 128 pounds.  I was 5'2" and 195 pounds.  It took me eighteen months to lose all of the weight.  I stayed at 142 for over six months, then lost the rest.  In year three I bounced back to 142.  Now I work hard to stay at my goal of 136. 

Surgery helps you to lose weight, but the weight does not drop off like magic.  You still have to diet and exercise.  The surgery makes it easier to stay on the diet, because of less hunger and not being able to eat a lot of food.  But it is easy to overeat, even with surgery.

You can stop the weight loss of any surgery simply by upping calories.  Everyone's body has a balancing point where their metabolism uses all the calories efficiently without storing excess fat.  You figure out what that level is in maintenance.  

Rather than focus on which surgery would prevent you from losing too much weight, investigate the lifestyle changes and the side effects of each surgery (because they ARE different) and decide what you are willing and able to live with.  If you want malabsoprtion AND reduced stomach capacity then look at the RNY or DS.  If you just want reduced capacity look at the VSG.