Starvation mode symptoms and conditions

just read through all the other side effects, and I think I should add weight gain as well -- I'd assumed my extra pounds were just from finally eating 3 meals a day after having gone months barely being able to eat a thing; thought my body was in starvation-mode and just keeping extra weight, but with all the people mentioning weight gain as a side effect I have to wonder if gaining 20 lbs in 4 months is more than my metabolism being out of synch! Lyrica does help for pain (neurological) but not so sure about the side effects.

My daughter (now 18) was diagnosed with Hashi's 2 1/2 years ago. She had headaches, was tired more than usual and irregular periods. Now on synthroid for 2 1/2 years, she has steadily gained over 35 lbs. She works out every day and eats ONE meal per day. Doesn't matter. Doctors all lie about this side affect. Her weight gain has made her borderline type 2 diabetes now. (she's about 170).

Is there anyone who's been through this and has a reasonable approach?