If you have a Muslim friend, there probably is a point in time where they mention something about fasting for Ramadan. In the religion of Islam, we fast in order to have empathy for the ones who are unfortunate and who cannot eat. We come to the realization at the end of the day, when we can eat, that we are grateful for the food that we do have.
In reality, the real lesson is not to worry too much about what we are going to have for dinner, and instead focus on being a good person.
The starting age for fasting during Ramadan is not a set number. It depends on who you talk to, but the choice is normally up to a child of when they want to begin. I remember that I started at the tender age of 6, as I saw everyone else doing it, and I wanted to join them. Again, the choice is up to the child.
The rules are simple: A person who is fasting for Ramadan cannot eat from sunrise until sundown. Obviously the time differs as the month moves along and the time of the sunset and sunrise changes.
I believe that fasting during Ramadan is a good thing, and it teaches us a lesson of peace, gratitude and empathy. As I stated before, it is not about the food, it is to help us, and teach us muslims to be better people in the end.