Don't eat staple food for lunch, fill your stomach with vegetables and fruits.

Don't eat after noon! That's all that matters. If you sleep late, you can eat something after midnight, but don't overdo it.

I don't know if you are a boy or a girl, but you insist on playing basketball for 2 hours every day. If you are a girl, try to find some sweaty but not very strenuous exercise.

People are different from people, so you don't need to be quick, just stick to it for a long time.

Add me, I have more experience.