You need to at least double that! It can lead to eating disorders and if you are and you are a teenager, or even a kid, you are in the middle of growing and not eating the right amount of calories can stop your growth. I don't know why you're eating only 600 calories, because if you feel you need to lose weight, there is exercise. I hope this helped! Don't be afraid to eat!
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If you feel like your calorie intake is out of your control, please seek some help. There are lots of people you can talk to- parents, doctor, teachers, etc.
Please do the best thing for yourself and stay healthy!