Malnutrition and Intestinal Malabsorption

Protein energy malnutrition of childhood is the most prevalent form of malnutrition in the tropics and throughout the world. Intercurrent infection, particularly gastroenteritis, measles, pneumonia, malaria and schistosomia-sis are known to precipitate overt disease. Associated subclinical vitamin and trace element deficiencies have been found to have an important additional role in augmenting morbidity and mortality attributed to protein energy malnutrition. A state of good health requires an adequate and balanced intake of nutrients. Minimal requirements for essential nutrients are dependent upon diverse physiological and climatic factors such as growth, pregnancy, lactation, illness, exercise, temperature and humidity. In addition individual responses to nutritional deprivation are quite variable. In tropical areas a high proportion of the population subsists on a marginal diet where carbohydrate provides 80%–90% daily energy requirements as compared with 35%–50% of the diet amongst prosperous people in temperate climates. It is widely recommended that dietary protein should approximate 1 g/kg body weight in adults while young children require two to three times this amount. In addition to contributing an average 10% of daily energy requirements, proteins contain essential amino acids that are important in metabolic processes. Tryptophan occurs in very limited quantities in white maize, the staple diet in much of Africa, where pellagra often accompanies protein energy undernutrition. In Asia, where thiamine deficient polished rice is the staple diet, beriberi tends to be associated with protein energy undernutrition.