Answer:
For one teens get addicted mostly through peer-pressure and two the brain becomes confused with whats wrong and whats right once you start and can't quit.
If you are going off of the three meals a day I would say dinner, you can sustain proper energy all day then at night you can rest and regain energy that way.
In some cases yes. Kids tend to learn faster than the average toddler.
The answer is 4,
I once heard my pe teacher say that the answer is always all of above in health
