So you think estrogen contributed to those 10 pounds? This will be a good experiment. Have you ever had your blood estradiol level measured?
Why is then, when estrogen wanes in middle age, it is harder to maintain lower weight?
When the hormone replacement system, The Wiley Protocol, was started, they took tons of estrogen and even more natural progesterone. A number of women complained that their doctors said they had gone seriously hypothyroid. There is some antagonism between estrogen and the thyroid but even from Lilypond's studies, it's not clear what it is. The ovaries seem to produce thyroid hormones too but I don't know if that has anything to do with it.