We need calories or energy to do things every day. For example, when we walk to school or ride a bicycle to school, we expend a certain amount of calories and even when we sleep, we use them. But how many calories should we have to stay fit? It's difficult for us to calculate. If people want to stay fit, they should remember that people should have between 1600 and 2500 calories per day.

We get calories from the food we eat. If we get too much food and don't participate in any activities, we can quickly gain weight. So, in addition to studying, we should exercise, play sports or do housework, such as cleaning the floor, cooking, etc... Otherwise, we don't eat enough, we will feel tired and weak.