AITAH for telling my mother to stop projecting her insecurities onto me?

I (19F) got into a fight with my mom (50f) yesterday.

She unexpectedly stayed home from work because they needed her to come in only in the afternoon. I already had plans to make my fave breakfast: two fried eggs with runny yolks, four pieces of buttered toast and vegetables.

I was making my breakfast and the first thing I did was toast the bread in the same pan which I later fried the eggs in (we don't have a toaster). I don't use oil to toast the bread, I just spread a thin layer of butter on both sides. She came into the kitchen, looked at the bread and asked me 'Are you seriously about to eat all this? You should be more mindful of what you eat.' in this condesceding, I know better than you, tone. I continued making my food trying not to get mind her comment.

The thing is, my mom is overweight, but she isn't obese. She has a bit of belly, which for a 50 yo woman who gave birth to a kid and has a sit-down job isn't unexpected to happen. She is very insecure about this, constantly looking for opportunities to mention how 'fat' she is and how she doesn't fit into anything. I've always been supportive of her, telling her she is beatiful either way etc. but atp it's pretty obvious she does this to fish for compliments from other people.

Recently she went on another one of her health strikes, she works out regularly, eats healthy snacks she prentends taste 'way better than chips anyway' and so on. Which is good for her by all means.

I on the other hand am comfortable in my own body, I am in no way an athlete, I have a bit of fat here and there, but I lead an active lifestyle, I don't work out because I sincerely hate it, but I do sports like swimming and horseriding and take regular walks and hikes with friends. I feel happy and healthy in my own body and my mothers comment honestly piss me off.

So when she came back to berate about my breakfast food choice, I told her to stop projecting her insecurities onto me, that I am happy in my own body, I am healthy, am not actively gaining weight, and have looked the same for the past two years so I don't see what she is on about. She called me a bitch and told me to 'wait until I get older and all the fat that I eat will start to settle in my body, and not to run to her when that happens'.

So AITAH?