I can kind of associate with you. I live with and care for my disabled mother. Since I started gaining weight, when I was like 8 years old, she has told me I was fat and needed to lose weight.
Now, at age 31, and it seems, now that I am actually trying to lose weight, whenever I make an adjustment to any recipe to maybe make it maybe a little more healthy, like low fat margarine, 1% or 2% milk instead of whole, brown rice instead of white, etc...), Mom throws a fit... and she's fat too, she weighs 20 lbs more than me now. She has tons of health problems like diabetes, strokes and heart attacks, etc.. I tell her I don't want to deal with the same health problems as she is when I am in my 50's, and she tells me "No, yours are gonna be worse than mine".... I say "How sweet, I love you too..." She was 5' tall and 270 lbs when she was my age, trust me, I remember, yet she seems to think that I am worse off than she was.... yeah, right.
Anyway, I don't know if she actually dislikes the stuff I cook or if she's just being stubborn and set in her ways, or if she's just jealous because she I'm loosing weight and she's not... She can be such a witch with a B sometimes..... I love her but sometimes she makes it hard.
I agree with the others. Don't allow anyone else to serve your plate, and don't take more than what you plan to eat. Eat it all, and don't give them any reason to complain about you wasting food. If they start to fuss, get the **** outa there, pronto.
Having a fit and throwing food at people is very immature and rude! If anyone ever threw food at me, I guarantee, they would be wearing my whole freaking plate, and whatever else I could get my hands on. I can be tempermental at times

There is no excuse for this behavior, but I believe in the expression, you get what you give....
Who does this to you anyway?