I know that they keep fast after noon but when do they break their fast and when are they allowed to eat their meal (between sunrise and noon?)
What is their method of fasting?
Actually it is not so much about "fasting". It is more on "refraining" from taking food. There is a subtle difference in that "fasting" means refusing to take food. Whereas, "refraining" means not to succumb to temptation to taking food unnecessarily.
Monks and nuns have their food in the morning before 12 noon. The rest of the day, they refrain from taking solid food. There isn't any "method of fasting". They eat before noon. That's all.
On a lighter note; the dietician say you are what you eat. The fashion designer will say you are what you wear. And the beautician will insist that you are what you put on your face! The Buddha said you are what you think!