I'm going to eat junk food in front of my baby brother and not give him any.
Why do want to eat junk food in front of your baby brother?
He has no money to buy food.
If your brother is in financial crisis, you're supposed to help not make fun of him by eating in front of him. You're very rude to make fun of your own brother for his situation.
I don't think he deserves any if he can't afford any.
Maybe help him get a new job or be supportive in other ways. You need to be a bigger person and help him out.