When planning a healthful diet, you should remember that?

We should remember that we should consume all necessary nutrients at a correct amount and proportion. this includes the primary food substance carbohydrates, fat and protein. and protective food substance in a small amount, which includes mineral ions ( iron, calcium etc) and vitamins. Also we have to take in enough water (6-8 cups a day) and fibre to prevent deficient diseases and to maintain health.
in addition, note that the amount of food intake varies with age, sex, body status, daily activity etc. For example, teenagers and pregnant women should increase all necessary nutrients intake to ensure proper growth and development of ourselves or the baby.