I had an overactive thyroid all my life when I was a child. Skinny as a stick, and I ate like a horse. Fast forward to after my first child was born, and I got radioactive iodine treatment. It totally dedstroyed my thyroid, making me hypothyroid.

I now take Levothyroxine (Levoxyl, which is like Synthroid) and Cytomel.

I'm sure not thin anymore but I eat like I am.