In war-time, opportunities arise for studying how the health of millions of people is affected by their having to consume a fairly standard diet over a period of several years. The diet consumed and the . state of health that prevailed during the last war have therefore been descriptionbed for several countries affected in varying degree by war conditions. It has been noted that in the countries where the general state of health was not only maintained, but improved upon - the diet was marked by (1) an increased or high consumption of milk; (2) the replacement of white bread by higher extraction bread; and (3) an increased consumption of potatoes and vegetables. The implications of these mass nutritional experiments, involuntarily performed, have been discussed, especially in relation to future food consumption trends in South Africa.