My sister has underactive thyroid as well. She maintains her weight as you, by excersice and really watches her carbs. So far, she is maintaining her weight to where it should be. She told me carbs are the key for her, but everyone is different.
I am clinically hypo (TT-15yrs ago), and under weight, so what works for one may not work for the other. I take my thyroid medication, but also take a B12.
I'm glad to find someone who share the same symptoms as myself. I was disgnosed with Hypothyrodism a few months ago and currently on Levothyroxine 125mg. I excercise regularly and keep the rigth diet but my weigth gain just continues to increase. I am 6 - 7 stones overweight as it is and i'm so frustrated about it. I am begining to feel really drepressed about the weigth gain as I can't fit into my clothes and uncomfortable at outings. I need some tips as well. Can somebody out there give some advice.