Chapter 3 Some basic facts about food

All nutrition trainers have adequate knowledge about food. This chapter is included here only to provide the trainers with a summary of the basic facts about foods that all community health workers must know.

Most of the information in this chapter is also mentioned later in different modules. However, it is recommended that trainers teach the information in this chapter to the trainees in an introductory lesson, i.e., before teaching the modules. This will make it easier for the trainees to understand the tasks in the modules.

This chapter is presented in the form of questions and answers so that the trainees can also use it for self-instruction. It is suggested that the trainer ask the trainees to read this chapter before discussing it in class. At that time, the trainer can provide additional information, if necessary.

What is food?

Everything that we normally eat and drink can be called food. Things consumed as food differ from one country to another and sometimes even within different regions of one country. The things people regard as food in different parts of the world have been selected by trial and error over hundreds of years. The community health worker must know what types of food are consumed in her area, what items of food people like, and what foods people do not eat even though they are cheap and abundant; the community health worker should also know why people do not eat certain types of food.

Why do we eat?

We eat whenever we are hungry. Satisfying hunger is just one function of foods, however; there are other important functions that we usually do not think about when we eat.

Basically, foods have three important functions for the human body: to provide energy, to sustain growth, to give protection from disease.

Functions of foods: · To give energy for all types of activity · To help the body to grow in size · To protect the body from diseases.

Different foods have different functions

Foods contain chemical substances known as nutrients. These can be divided into three categories according to their function: energy-giving nutrients, body-building nutrients, and protective nutrients. Most foods contain a mixture of the three categories of nutrients, but usually in one type of food one of the categories is present in a larger amount than the other two, and the function of that nutrient becomes the main function of that food. For example, cereals such as rice and wheat have all three categories of nutrients, but the energy-giving nutrients are the most abundant, and therefore giving energy is the main function of cereals. However, if a cereal is taken in large amounts, it can also supply sufficient nutrients for promoting growth. For example, in several South-East Asian countries rice not only supplies energy, but a major part of the body's need for body-building nutrients.

Commonly eaten foods can be broadly divided into three groups according to these three functions. All community health workers should remember these food categories.

Energy-giving foods:	Cereals like rice, wheat, corn, or millets. Fats and oil Starchy vegetables like potatoes, sweet potato, cassava Sugar, molasses, and honey
Growth-promoting foods:	Most foods of animal origin, e.g., milk, eggs, fish, and meat Some foods of vegetable origin, e.g., pulses, peas, beans, and nuts
Protective foods:	Vegetables, especially the green leafy type. Yellow- and orange coloured fruits and vegetables like carrots, papaya, mango, tomato, orange Fruits with sour juice like orange, lime, lemon, grape fruit

What should we eat?

There is no such thing as an ideal diet. But to live a healthy life we must eat a mixture of foods, some that give energy, some that promote growth, and some that protect from disease. (In the case of adults, growth-promoting foods are needed for the repair of the daily wear and tear of the body.) Thus, we should not be guided only by our taste. The quantity of each type of food and combinations can of course vary.

Quite often children are fond of eating sweets and reject other foods which are good for them. This is harmful for the body and teeth.

Is there any dietary pattern in developing countries?

Yes, there is a dietary pattern, especially in the case of adults. Men and women living in different countries and in different environments remain healthy on diets that differ widely. Delicious foods in one country are not even regarded as food in others. In spite of these differences, there is a common pattern among adult diets in developing countries even though owing to poverty the choice of foods is limited. The pattern is as follows:

· The main part of the diet consists of cereals such as rice, wheat, corn, or millet or foods prepared from these cereals. Cereals are normally the cheapest part of the diet. In some parts of the world plantain, cassava, or potatoes form the main part of the diet instead of cereals.

· Supplementary foods include pulses, beans, and peas. These are always eaten with the cereals. They give variety to the diet and make the cereals more palatable. Similarly, vegetables are also eaten with cereals and pulses to increase palatability and variety.

Thus, in most developing countries the majority of the people live largely on diets made up of cereals, beans or pulses, and some vegetables. However, some other types of food are also consumed in lesser quantities. These are foods of animal origin. They are the most expensive items of the diet, and include meat, fish, and milk and milk products. Fats and oils, which are mostly used for cooking foods, greatly improve the taste of food.

Since foods of animal origin are generally expensive, only rich people can afford to eat them regularly. Animal fats are more expensive than vegetable oils. With improvement in economic status, the quantity of fats and oils in the diet increases.

A daily diet should be a mixture of: · Cereals · Pulses, beans or peas · Vegetables, preferably of the green leafy type. Animal foods are a welcome addition.

Are animal foods essential?

No, but they are desirable. As mentioned earlier, animal foods are very useful for promoting growth in children. In adults, growth-promoting foods are needed for the repair of the daily wear and tear of the body. In fact, even when the body is still growing, some wear and tear does take place and growth-promoting foods are needed for repair. Protein is the nutrient specially suitable for this function. The protein found in all animal foods is of high quality, and it is present in large amounts.

However, vegetable foods like peas, beans, pulses, and nuts also contain large amounts of protein, and therefore can promote growth as well. But the protein in such vegetable foods is of a lower quality. However, when two or more protein-containing vegetable foods are mixed, the protein in the food mixture is almost of the same quality as that found in animal foods. The community health workers should know the types of food mixtures that give such superior combinations. The following are two good combinations:

· Double mix: Cereals plus pulses-e.g., rice and pulses, corn and beans, and wheat and pulses or beans or peas.

· Triple mix: Cereals plus pulses or beans, plus green leafy vegetables. In some societies plantain, potatoes, or cassava are used in place of cereals. These are as good as cereals for double and triple mix foods.

Mixtures of vegetable foods are almost as good as animal foods for growth promotion.

If animal foods are within the family budget and are normally consumed, then the addition of even a small quantity of animal food to a vegetable food mixture greatly improves the growth-promoting effect. This is specially important in the feeding of infants and young children.

Animal foods are not essential. They are desirable, especially for infants and young children.

Mothers' milk is an excellent addition to vegetable food mixture in promoting growth of infants and very young children. That is why the advice to all mothers should be to continue breast-feeding as long as possible, because even a small quantity of mother's milk can greatly improve the quality of vegetable food supplements the infant or the young child is getting. This is more important if the mother cannot afford to give other types of milk (e.g., cow's milk) to her infant or child.

When are growth-promoting foods most important?

Infants and young children grow very rapidly. A healthy new-born baby doubles his weight in 5 months. This growth is the result of increase in the amount of soft tissue (muscle, skin, etc.) and in the size of bones, which make up the frame of the body. Thus, children need foods that promote the growth of both soft tissues and bones.

Proteins are nutrients that promote the growth of soft tissues. Minerals (another type of nutrient) promote the growth of bones. Foods for young children should contain both these nutrients.

Milk is excellent for the growth of muscles and bones in infants and young children-breast milk is best.

The following is a list of some categories of foods that are excellent for the growth of infants and young children:

· Pulses such as lentils and grams (green gram and black gram)
· Peas and beans (e.g., soya beans)
· Nuts (e.g., peanuts)
· Vegetables (especially the green leafy type)
· Milk and milk products
· Other foods of animal origin (e.g., meat, fish, and eggs).

During pregnancy a woman's body grows very rapidly. This growth takes place not only inside the womb, but also in her own body. In the course of only 280 days of pregnancy, a tiny fertilized egg cell grows into a fully formed baby of 2500 grams or more. The raw material needed for this tremendous growth comes from the diet of the mother. If the mother lives on a poor diet during pregnancy, her baby will be lighter and smaller (low-birthweight infant). Such babies can be regarded as malnourished. They are vulnerable to not only nutritional deficiencies but also infectious diseases.

Dietary care in pregnancy is the starting point for good infant nutrition.

Breast-feeding mothers also need extra growth-promoting foods. Human milk is produced in the breasts of the mother from raw materials which come from her diet. In order to produce enough milk of good quality, a mother must have a diet consisting of adequate amounts of cereals, pulses, beans, vegetables, oils, and, if possible, animal foods.

Why should we pay special attention to the feeding of infants and young children?

It was mentioned above that infants and young children grow very rapidly. There is growth of soft tissues and also of the bones, for both of which special care has to be taken to include growth-promoting foods in the daily diet. However, it is important to pay special attention to the feeding of infants and young children for other reasons:

(a) Although infants and young children are small and appear to be inactive, they are in fact very active. Their need for energy in relation to their body size is much greater than that of an adult. This fact is usually forgotten. Special care is necessary to include in the diet energy-giving foods like cereals, fats and oils, and sugar. Giving growth-promoting foods alone is not enough.

(b) Infants and small children have no or few teeth. This means that they cannot eat solid or hard foods that require chewing. Therefore, only liquid or semi-solid foods should be selected for them. If solid foods have to be given, they should be prepared in such a way that they become soft. Some foods do not become soft even after much cooking (e.g., certain tough, fibrous vegetables); these should be avoided even though they are nutritious. Soft, cooked cereals and pulses, boiled mashed potatoes, and cooked, mashed, and sieved vegetables are very suitable preparations to start with. Do not forget to add a little oil or fat in the preparation.

(c) Infants and young children have small stomachs and therefore they can eat only a small quantity of food at each feed. Adults on the other hand eat only two or three big meals a day. In the feeding of young children, the golden rule is to give small and frequent feeds.

Remember: · Infants and young children are very active and need a lot of energy · They cannot chew properly · They can eat only a small quantity of food at each feed. Therefore, give them: · Both growth-promoting and energy-rich foods · Foods of soft, semi-solid consistency · Small but frequent feeds.