I have underactive thyroid and IBS . I am on 125 of Levothyroxine. The thing that is driving me mad is my weight and lack of energy. I have been told to follow a Gluten free diet (my son is coeliac) which is mostly helping with IBS (not all the time) but I have not eaten bread, cake, biscuits etc at all for 16 weeks now, trying to use this to lose weight but I am still gaining weight ! I cannot tell you how little I do eat now but still it goes on, I am getting truly depressed by it. I have an active enough lifestyle but do need to up exercise but the fatigue doesn't help.