Weightloss before surgery

Does weightloss prior to surgery slow weightloss after? My doc says he thinks 20lbs for me would be good the first month.

I'm not sure. Some people have to do a liver-shrinking liquid diet for a week or two before surgery. I did and lost 11 pounds in a week and then lost 9 the week after surgery. Remember though that there may be swelling from the IV fluids and some people have a stall around week 3. I actually lost better months 2 and 3, more steady.