There is alot of information in weight gain with an underactive thyroid but i have yet to find anything on an underactive thyroid in people who can not gain weight.
My reasons for posting this are that i may gain some information on why i feel so ill some of the time and not gaining weight and its reasons could be a clue to wellness.
I am not underweight but if i am sick or cant eat for even a short time my weight can just fall off of me. Iv always had a thing that i wanted to be heavier but this never happened. I think alot of the way i think goes back to when i was very ill with crohns disease and i went down to five and a half stone. I was ill and looked ill, now i associate wellness with weight making a person look well. Obviously i know is not the case as many people are not well yet they can not loose weight due to their illness.