The importance of malnutrition as an international problem is illustrated by some examples. Attention is mainly focussed on the bipolarity of this problem: malnutrition, both qualitative and quantitative, as the main nutritional problem of most of the developing countries of the Third World, overfeeding nowadays so associated with qualitative malnutrition - as the most important alimentary problem in the Federal Republic of Germany, but applying equally to other highly industrialized and civilized countries in Western Europe, the United States and Australia. Perhaps it would be more to the point to speak of prosperous countries or populations because these diseases found in technically highly developed countries increasingly occur also in developing countries among those social classes who believe they are able to afford a "better" nutrition and fall from one extreme of malnutrition into the other. Correct nutrition considered to be a privilege or a direct consequence of social prosperity is certainly not justified. The improvement in the standard of living as such by no means guaranties well-balanced nutrition. To quote an example: in developing countries when people live by trading with certain limited products, alimentary habits tend to change when the prices of the products go up. However, this is by no means invariably a change for the better, but quite often for the worse. It has repeatedly been found that in tropical countries where copra is the staple trading product, nutrition did not improve as the copra price rose. On the contrary, nutrition deteriorated because the people increasingly turned from the self-cultivated "natural products" to imported, refined food stuffs and tinned foods purely for reasons of increased prestige associated with such a diet. The consequences of malnutrition in the developing countries are dealt with in greater detail. In dealing with the consequences of malnutrition in highly industrialized countries a restriction to a few pointers was necessary because this subject is discussed in the following paper.