d and fed, a role that low-cost formulated foods can serve.
Also, in some circumstances it is not possible to provide a nutritionally adequate diet for infants and young children from breast milk or affordable unprocessed local foods. Examples include when the mother dies, when lactation fails, when natural catastrophes decrease available food supplies, and when political upheavals dislocate families. In such emergencies, formulated supplementary foods may provide the only suitable temporary alternative for older infants and young children.
Supplementary or complementary foods are formulated food mixtures meant to be used in addition to breast milk (or breast-milk substitutes) for infants from the age of 46 months until weaned, and thereafter in addition to local foods in order to provide diets that meet nutritional needs.
Processed foods are items that have been modified to achieve special characteristics, such as to improve digestibility, palatability, and ease of preparation.
Age ranges are defined as follows: younger infants, from birth to 4-6 months; older infants, from 4-6 months to 12 months; young children, 1 to 3 years.
PROPOSED MODEL FOR FEEDING OF SUPPLEMENTARY FOODS
Figure 1 shows a conceptual model for timing how foods should be used to complement breast milk so as to meet fully the energy and nutrient needs of infants and young children. Small amounts of the supplementary foods are required initially; their main purpose for older infants is to provide an additional safe source of energy that complements that of breast milk and fully supports growth and development. Beyond the age of 6 months, supplementary foods should gradually be increased in amount and variety to provide not only energy but other essential nutrients, including protein, vitamins, and minerals.
FIG. 1. Conceptual model for the introduction of supplementary foods into the diets of infants and young children (Source: Underwood and Hofvander (4])
The non-nutritional role of supplementary foods in traduced to older infants should also be recognized. These foods help to condition (educate or acculturate) infants and young children to a wider diet at weaning by providing experience with transitional liquid-to-solid variations in consistency, texture, and taste.
The nutrient composition of formulated supplements may have to be adapted to local circumstances since these foods are meant to provide such nutrients as are lacking in the basic staple food as defined by the Codex Alimentarius Commission [1, 2]. Local economic, cultural, and social acceptability factors also may influence the proposed composition of main ingredients. In addition, adjustments of a base formulation to reflect local conditions of use may require additions or deletions of certain vitamins and minerals to ensure that the daily total intake remains within safe limits.
Of greatest concern is assurance that the total diet provides the essential vitamins and minerals at a level that meets minimum nutritional needs, and that the intake of nutrients that are stored in the body, such as fat-soluble vitamins and minerals, does not consistently exceed maximum safe limits.
RAW MATERIAL USED IN SUPPLEMENTARY FOODS
In developing countries, for social and economic reasons, the raw materials used in supplementary foods should come from locally available ingredients wherever possible. The supplementary foods that are considered here are entirely or mainly based on raw material of vegetable origin. The basic ingredient is a cereal, to which are added pulses and/or oilseed flours. Animal products, such as fish or fish-protein concentrate and milk-powder products, could, or should, be added if feasible, acceptable, and economical. To increase the energy density, fat (and/or sugar) should be included among the ingredients or added to the food when it is eaten.
All milled cereals may be used to make supplementary foods. Certain cereals with a high fibre content such as millet, sorghum, and teff should be processed in such a way as to reduce the fibre content. The model composition proposed by th