Is this bad to do....?!
Question: Is this bad to do....?
Answers:
You are 14. Why the hell are you on a cabbage soup diet? You're likely not getting the nutrients you need which is thus causing your pain. Growing pains are just a myth.
Quit being dumb.
Common Sense
Why are you on a diet? You're not done going through puberty and you're not done growing. Enjoy your metabolism while it lasts!! Growing pains can be painful yes, but are you sure they aren't pains from your body not getting the nutrients it needs to survive??? Stop this ridiculous "diet" and eat some pizza or mac and cheese. Your body will break it down and get rid of it normally and you'll stay thin.