Thyroid & diet.

Is there anyone out there who knows about hypothyroidism and diet? I have been hypothyroid for many years now but in spite of my low-carb diet (of ten years) I have been unable to regain my pre-hypothyroid weight. I am healthy but REALLY fed up trying to lose this extra weight! (Around 11stone.)

I have over the years tried everything I can think of - more exercise (not good for hypothyroids as I soon found out) lower carbs, more fat, coconut oil etc. to no avail. Help!