I m 60 years old. I had a radical hysterectomy at 41. Severe sweats kicked in right away, but were controlled with estrogen supplements, patches, and during the last 10 years, the Femring. Can prolonged use of these HRTs cause weight gain? I m only 5 2 and am at 168 pounds. However, I do Pilates 3 times a week for one hour each session. I don t eat large amounts of food. But I do drink about 3-4 diet colas a day. I m returning to Weight Watchers this week, although I ve tended to eat the things that helped me lose weigh before. Now, the weight doesn t seem to come off as easily. I m also retaining a lot of fluid as my rings are difficult to get on and off. This started about 2 months ago.