It is possible to define a balanced diet in terms o eating patterns which are safe under most circum
stances. However, the first problem we are up again here is trying to define a balanced or safe diet
because of the sheer diversity of human diets- Oriental o various kinds, Mediterranean,
Anglo-Saxon, Scandinavian, Pacific Island, Inuit (Eskimo), Aboriginal, kosher and many more. Is
it possible that we could generalis for all of these food cultures?
Rather than talking about a balanced diet, there are two important principles we can follow.
Firstly, we need to obtain our essential nutrients from a wide variety of foods. Some foods like
wheatgerm or liver are nutrient dense (i.e. contain a wide variety of different nutrients) and reduce
the need for variety. Also, there must be real biological diversity in the foods chosen. For
example, eating beef and cabbage at one meal and a lamb chop and broccoli at the next is not true
variety, since both meals consist of a red meat and a vegetable from the same family. Secondly,
we must eat enough to obtain all the essential nutrients in sufficient quantity, and to do this we
must be physically active. Together, variety and sufficiency are the two most important principles
to ensure good nutrition.
The term balance begs the question, balance between what and what? Certainly, energy (kilojoule)
balance, between the energy contained in food that is eaten and that expended in activity, is
important. If there is a balance between the two, then our weight will remain constant. If there is
an excessive intake of energy, we will put on weight. If we use up more energy than we get from
food, then we will lose weight. Relationships between nutrients like amino acids, fatty acids,
vitamins and minerals like copper and zinc are also important and can be reflected in food choice.
An example would be the need to eat both cereals and legumes to obtain all needed amino acids.
If this is what is meant by balance, then it is fine. Food is so chemically complex that one food is
unlikely to be exactly nutritionally equivalent to another. But putting such a concept in practice
requires much more knowledge than does using the principle of choosing from a wide variety of
biologically different foods each day.
Furthermore, because balance is used imprecisely, certain foods are misleadingly presented as
essential for good health.
The principal or staple foods used in many cultures have often arisen out of economic necessity to
provide enough energy. Having a staple food does not ensure all-round essential nutrient
adequacy. For example, riboflavin deficiency has occurred with rice as a staple and pellagra
(niacin deficiency) with maize as a staple.