There is now ample evidence that, of the many problems which afflict the poor countries of the Third World, the problem of nutrition is of pivotal importance and of far-reaching implications. It is now known that malnutrition not only contributes directly to considerable -health and disease in these countries, but that it also reduces resistance to infectious diseases of various kinds. It is also being increasingly realised that, in the context of undernutrition and high child mortality, programmes of family planning in many of these countries have had only limited success.