Thanks for the input everyone. I feel abit releived now. Certainly body mass, muscle mass and activity play a part. Also, I feel that being on Thyroid pills has an influence although a doctor will never acknowledge that. I have tried. Our Thyroid is like a little engine that drives the car. If it isn't working properly because of having cells killed off and being on pills to maintain a level...then surely that would influence metabolic rates.
When I stuck to induction years back I was hard pressed to take in 1000 cals a day. I lost weight, about 15 pounds. I figured it was from the low calories. I hardly eat carbs now but limiting them like in induction might have been the key for me. a potbellied woman.