When purchasing health food, consumers should make clear the principle that health food can not be eaten as ordinary food, nor can it be used to treat diseases instead of drugs. The fundamental difference between health food and medicine is that health food can not be used to treat diseases, but only has health function. Some manufacturers or individuals make use of illegal advertisements to exaggerate publicity, claiming that "all diseases can be cured". Citizens must not be deceived by illegal false publicity. If they are sick, they should go to the hospital in time to avoid delaying normal treatment. The drug approval number starts with "national drug approval", and the approval number of health food starts with "national food health" or "x health food health". Citizens must see the "approval number" clearly when buying. Never buy products without an approval number to avoid being cheated.