Food and nutrition.
Different people will need a different daily calorie and it's also depend on the activities related to the individual. For example an adult athlete will need to consume more calories then a regular school girl.
When eating store-bought foods, be sure to look at the nutrition label to see how many calories are in one serving. When eating out, choose what you’ll eat before you go. Most restaurants offer nutritional information online.
Make sure you read the label, because lack of nutrition can cause your body to be weak while too much nutritions and calories also is not for your health. So always keep a balance when you consume food.