Caffeine is a chemical drug just like alcohol and nicotine.   The effects of caffeine are far stronger than many people realize, especially with regards to kids.  Caffeine is addictive, just like nicotine, and this is why it is very difficult for people to stop using caffeine.   In extreme doses, caffeine is lethal.  Caffeine can be found in many of the foods and drinks we use everyday.  Caffeine is seen most strongly in coffee, but it can also be found in a number of different soda products.  As far as food, caffeine is most strong in different types of ice cream and frozen yogurts.  Caffeine is also found in abundance in many pain relief pills, such as Excedrin.    

Caffeine has a number of negative effects, but most people drink it because they say it helps them stay alert.  Well, this may be true to some extent, but especially with children whose bodies aren’t fully-grown, caffeine does much more harm than good.  One of the long-term effects of excessive coffee drinking at a young age can be stunted growth.  The most immediate effects are stomachaches, headaches, nausea, nervousness and dizziness.  Caffeine also reduces general motor-skill coordination, and causes insomnia.  These symptoms may not seem too serious, but caffeine takes hours to fully remove itself from your body.  On average, the chemical will only remove 50% of itself from your body in 6 hours.  This means when you have a cup of coffee in the morning, it can take the rest of the day before all of the chemicals and its effects are fully removed from your body.  Many people are so used to drinking coffee or soda, they don't realize the effects it's having on their body; they never make they connection between the caffeine and the effects.   
 
In school, caffeine can make focusing on work and functioning properly very difficult.  What caffeine does to your brain makes you more physically alert, but also can make you restless, and unable to focus on work.