I know there is no research linking HRT to weight gain, and weight gain is likely to do with the menopause rather than HRT. But I appear to be the exception to that general rule.
Since tapering off HRT about a month ago, I have lost about 1.5 - 2 kg, without any significant changes to my diet ( pretty good anyway) or exercise. I was on HRT for about two years, during which my bust went up by two cup sizes! and I put on lot of weight around my tummy. Went up from a size 12 to a 14.
It was great in other ways, but I decided to go off it and see what happened. Feel much less bloated and fit in my jeans again. Doctors may say HRT has no link with weight gain, but I think it may have in some cases?