Everyone wants to be healthy. We know food is very important to us. There is an old saying-----"An apple a day keeps the doctor away." There is lots of healthy food in our life. Fruit and vegetables are healthy food, but hamburgers and candy are not healthy food. So you can have more bananas, apples, oranges, tomatoes and onions. They are good for us. But you'd better  not have  hamburgers or candy. They are bad for us. For drinks, juice and milk are healthy but Coke isn't healthy. Ice cream isn't good either. Healthy food can drinks make us strong and happy. What does "An apple a day keeps the doctor away." mean?
You eat an apple every day and you can be healthy. The doctor eats an apple every day and he goes away. The doctor runs away when you give him an apple. The doctor doesn't ask you to eat an apple every day.