I'm 40 and 125 pounds. She clearly does not eat much. She claims she eats all the time and has a big dinner she makes every night. She piles up her plate and doesn't eat most of it. The doctors apparently tell her her weight is fine, though, they'd like her to gain a little.
I've had a dang hard life to be living with this controlling behavior for years to come. If I don't eat when her dinner is ready she gets nasty. If I don't eat she will refuse to eat. Or she'll wait on me, whatever I may be doing, to cook even if she's hungry. She'll whine about just throwing the food away if I don't eat right then. If I do what I want, she'll chase me later, and madly explain your dinner is in the microwave.
She absolutely never wants to eat out, fine, but I don't ALWAYS want what she likes to cook for herself. She doesn't normally cook what I like or even ask, and if she does ask she normally doesn't cook it loll
I appreciate having someone to cook for me, I just don't want to be controlled by it most days of my life.
You are separate people with separate tastes, nutritional needs & appetites. Repeat this is often as necessary until it is understood.
You can eat what you want, when, where & how.
Your Mother can eat what she wants, when, where & how.
I really struggled to feed my mom what she would like, and she wouldn't have something like a cup of tea or such unless I was going to as well--drove me crazy!
She cooks, you eat. That's the parent child dynamic that is really hard to break.
I would try to plan a weekly menu together and see if that helps. Try and tell her that you do or don't like something, maybe post it. Amber doesn't like cow tongue, DO NOT COOK ANY FOR HER! She really loves grilled fish, ADD MORE TO THE MENU!
With dementia the only certainty is that whatever works today, won't work in the future. It is a constant trial and error. Learning to be fluid with what you do, will save you tons of frustration.
If you want someone else to change, good luck with that. Change yourself, and you'll have much better luck. You can only control your own behavior, not someone else's.
You're 40. Move out and on with your own life.
When I was a child, my mother forced me to eat a soft boiled egg every morning of my life. The very moment I was old enough to be able to do so, I moved out.
I never, ever eat eggs, to this day, and I'm 64 now. That's the beauty of being an adult. I get to eat what I want, when I want.