If you eat 500 calories will you faint?

uhm...yes you will faint, maybe even more than that. 500 calories is a DANGEROUSLY low calorie intake. A NORMAL growing teenager should at LEAST intake 2000 calories daily. if you want to loose weight than maybe eat 250-500 calories less than what you normally consume. but the best way is to burn more than you consume. even stretching helps with burning fat. your body burns 1200 calories everyday just by resting.