We should choose food according to food groups

Food can be grouped in many ways, and this concept can help us to choose our food wisely. Many countries have formulated nutrition education programs around the concept of food groups. In Australia, the Department of Health encourages food choice from five food groups in the following way:

FOOD GROUP

DAILY SERVE (Adult)

Bread and other cereals 4 servings
Fruit and vegetables 4 servings
Meat, fish, legumes, nuts, eggs 1 serving
Milk and dairy products 300 ml or 40 g cheese
Fatty spreads and cooking oils 1 tablespoon


The five food groups approach is just one way of thinking about food. There is no particular nutrient basis for the five food groups, although such reasons are often suggested. Take a nutrient like protein, for example, which is found in significant quantities in animal products like meat, fish, eggs and milk, and also in plant derived foods like cereals, legumes and even root vegetables like potatoes. The nutritional quality of the protein, or rather the amino acids that make up the protein, differs, and if amino acids are only obtained from plant foods, it is advisable to have complementary protein sources from, for example, cereals and legumes, even at the same meal to ensure that all essential amino acids are obtained. With a plentiful food supply, however, even this is not very critical.

Iron can be obtained from cereals, but its bioavailability (availability for absorption into the body) depends on the simultaneous eating of, for example, vitamin C containing fruits or vegetables or of some meat; it is not necessary to have meat to get iron.

For a favourable calcium balance (when no more calcium is lost from the body than is consumed) it is not necessary to have dairy products. Calcium can also be obtained from a variety of foods such as green vegetables, legumes (beans) and nuts. There are many factors in food which reduce the calcium in the body, for example sodium, caffeine, protein and alcohol, and some people may need additional calcium (see WOMEN NEED MORE CALCIUM THAN MEN).

Indeed the strength of the food group classification is its emphasis on foods rather than nutrients. There are many interesting chemicals in food which have not been defined as nutrients, but which may be physiologically important. For a long while dietary fibre or roughage was thought a useless part of food, but now it is regarded as very important for human health. It is found in unrefined plant foods, but not at all in animal derived foods.

So there may be other useful ways of grouping foods, depending on the nutritional question. Some examples would be:

According to biological source:

The advantages of this approach are that it allows people to identify the key nutritional characteristics of a food and encourages choice from a wide variety of different foods. Greater variety tends to lessen the likelihood of chronic nutritionally related disease, be safer and make it more likely that you will obtain the full range of nutrients required. Appendix 4 provides further information on grouping food according to their biological source.

2. According to time of day eaten:

According to likelihood of protecting against or contributing to chronic disease like coronary heart disease, non-insulin dependent diabetes, gall bladder disease, obesity, large bowel cancer, cirrhosis of the liver and osteoporosis (thin bones):

CONTRIBUTE

PROTECT

This approach to food selection, through a knowledge of foods that contribute to and foods that protect against disease is often called 'the prudent diet'.

The prudent diet may vary from one culture to another. For example, in a country where the main health problems are protein-energy malnutrition, nutritional anaemia, blindness due to vitamin A deficiency, or iodine deficiency disorders like goitre and the medical condition of cretinism, a prudent diet would include foods that help prevent these conditions.

It is interesting and important to look at the way different people group foods instinctively or according to their cultural background. Examples would be:

MORAL

FAMILY

SOCIAL OCCASION

The moral, family and social roles of food cannot be easily separated from the nutritional roles. Recent evidence indicates that the social occasion of eating may have health-related effects in its own right.

Thus it can be seen that a particular food group classification needs to be seen in its historical, educational, social and medical context. There is no one 'best' way of choosing food.