The basis of the diet for most people is a core food, referred to as the ‘staple’, around which the majority of meals are constructed. Without the staple, a meal would not be perceived as a meal. There are usually only a very few core foods in any one culture, sometimes only one. They are generally cereals, or roots and tubers.
Secondary foods are also eaten; these enhance the meal, but are not an essential part of it. They may be endowed with specific properties of their own; for example they may promote strength (protein-rich foods, such as meat) or good health (fruit and vegetables), or they may maintain bodily forces in balance (‘hot’ and ‘cold’ foods as in some Eastern cultures). In addition, some secondary foods may be important at particular life stages.
The third category of foods are peripheral foods. These are non-essential, but pleasant to eat. Examples include biscuits, cakes, confectionery, preserves, sauces, puddings and alcoholic beverages. They may also include flavourings and seasonings.