We have three meals a day.
In the morning, we have breakfast. It is about at 6 or 7 o'clock. Breakfast should be good. We have milk, eggs, and other things. Some students often have no breakfast. It is very bad for their health.
In China, lunch is the main meal of the day. It is at about 12 o'clock. There are often three or four dishes(菜). It is a big meal. We should be full after lunch.
We usually have supper at about 6 or 7 o'clock in the evening. We should have a small supper.
But in England, people call the main meal dinner. It often means supper.