I only ate 900 calories today...?

eating low calorie once won't make you go into starvation mode, S mode take upto 3 months before it starts. If it's one day it shouldn't matter as long as you body got it's nutrients especially since it's night you'd end up storing it in your sleep. There are days where i eat 1200,100,1500,900,1300,etc,etc.

I still feel and look perfectly healthy :)

working out is up to u

It not healthy at all. You need to be eating a lot better than this.

Just because something says low/no fat or low/no calories doesn't mean it's good for you. It means it's processed with chemicals in order for it to taste good once they've taken the calories and fat out.

PLease talk to your parents and see a doctor.

You need to be educated on how to eat healthy and not deprive yourself of food. Eating healthy means no dieting but allowing yourself to have enough calories to fuel your body.

I'm a 13 year old girl and I have like 500 calories today. I'm not anorexic I just wasn't hungry after that. It happens. If your hungry then eat. If your not then don't eat. It's all about how you are feeling.

are you anorexic or bulimic? cuz 2000 energy is frequent for a girl. in case you consume extra, (healthful), and in case you artwork out for 30 min an afternoon then you definately'll earnings weight yet you would be at a healthful weight. adult males dont like stick ladies they prefer ladies at a healthful weight.