If I get a hysterectomy will I gain a bunch of weight?

I know that a hysterectomy isn't a cure for endometriosis but my doctor and I think that it will be a good idea but the thing is is that I don't want to gain a bunch of weight and I worked so hard to lose it. I saw how my mom had a hysterectomy and she gained probably like 70 lb. Is there a way I can prevent that from happening I am in my early 30s but my periods are very painful from endo.