Nutrition Issues in Developing Countries: Part I: Diarrheal Diseases, Part II: Diet and Activity During Pregnancy and Lactation (1992)

The rapid rates of growth and development of infants and young children require that feeding practices be continuously adjusted. Feeding regimens that are appropriate for the 3-month old are inadequate when the infant is 6 to 8 months of age, and practices suitable at those ages are unsatisfactory at later stages of infancy. Data that assess this process have led to the following conclusions and recommendations.

• Undernutrition, as assessed by anthropometric criteria, predisposes infants and children to diarrhea and to its duration and severity.

• Sociocultural determinants of feeding practices must be incorporated in the design of interventions targeted at improving nutritional status and risk of enteric disease.

• Exclusive breastfeeding for as long as practical and as long as an infant's normal growth is maintained minimizes a child's risk of enteric disease.

• Maternal nutritional status appears to affect milk volume; its impact on milk quality is more variable and less understood.

• The continuation of breastfeeding after the introduction of complementary/supplementary foods provides partial protection to the infant against enteric disease.

• Enteric pathogens are transmitted by the fecal-oral route, and foods ingested by children are major vehicles of this transmission.

• Utensils used for food preparation, storage, and feeding are common sources of bacterial contamination. Weaning foods given to young children are common routes of transmission for some bacterial

enteropathogens. Furthermore, initial fecal contamination of foods, poor hygiene practices in food preparation, and poor food storage practices contribute to food contamination.

• Unacceptably low nutrient densities often limit the appropriateness of traditional weaning or supplementary foods.

• Specific hygienic behaviors related to feeding practices, eg., handwashing, reduce the incidence of diarrhea in people in developing countries, and additional interventions to reduce food contamination should be evaluated.

• Multiple rather than single approaches (eg., adjustment of pH, high solute concentrations, and reduced water content) are more reliable for the inhibition of bacterial growth in foods.

• Evaluations of food processing options must consider food preferences, availability of raw ingredients, capital and labor requirements cost, local child feeding practices, and the sociocultural acceptance of foods produced.

Nutritional interventions intended to reduce diarrheal disease in children have three principal objectives: (1) enhancement of the child's nutritional status, (2) reduction of the risk of infection, and (3) reduction in mortality and severity of morbidity following infection.

Interventions to meet these objectives should be targeted at (1) support of the initiation and continuation of exclusive breastfeeding for at lent 4 to 6 months postpartum and partial breastfeeding for at least 1 year and (2) improvements in the preparation and use of appropriate weaning foods.

Factors that discourage mothers from breastfeeding should be countered by educating mothers, nurses, physicians, and other health care providers and business and other community leaders. We must stress (1) the value of breastfeeding to infant health, (2) improve our knowledge of infant feeding practices among diverse communities and the consequences of local practices to infant health, (3) create environments and policies that encourage breastfeeding among mothers who work outside the home, (4) ensure the availability of sufficient and appropriate food for nursing mothers, and (5) ensure the appropriate use of nonhuman milk products when they are medically indicated.

Efforts should be directed toward the reduction of bacterial contamination of home-prepared and commercially prepared foods fed to children and

toward the improvement of the nutrient content, bioavailability, and caloric density of supplementary and weaning foods with reduced preparation time and fuel consumption. Maternal education programs that emphasize appropriate practices of food handling are indicated. Such programs must be developed and implemented within a well understood cultural context to minimize barriers to change and to maximize effectiveness within communities. Such programs should improve household hygienic and food preparation practices, eg., handwashing and water use; use of proper storage conditions for prepared food; use and cleaning of utensils for feeding and food preparation; identification of cultural concepts of infant foods; enhancement of the preparation and use of nutritionally and culturally appropriate foods; and when indicated, improvement of food storage habits, food preparation techniques, fuel use, and family food consumption patterns.

Programs are needed to adapt food processing techniques to local needs. These efforts should lead to culturally appropriate foods with high caloric densities and nutrient bioavailabilities; the foods should require small amounts of fuel and short times for their preparation, and they should be within the economic reach of targeted populations.

The focus on nutritional strategies to reduce the risk of diarrhea and to minimize its severity and duration moves pediatric health objectives beyond child survival. The following research recommendations are made with that general objective as their goal.

Research programs are needed to develop improved implementation schemes for the interventions recommended in this report. Methods for effecting behavioral changes in specific cultural contexts are of particular importance because many recommended interventions target specific behaviors.

Studies of the roles of hygienic practices, household resources, and food storage and preparation techniques in the transmission of enteropathogens should be emphasized.

Understanding of infant feeding practices and factors that shape them remains limited. Of particular importance is an improved understanding of factors that lead to the introduction of foods other than human milk. Similarly, limitations in the understanding of human lactation physiology restrict the design of effective interventions. For example, there is limited information that identifies how the content of protective factors in milk may be enhanced; there is also limited information about the nutritional factors that limit the duration of effective lactation.

Additional studies are needed to evaluate the influence of infant supplementary feeding programs on morbidity and mortality as a result of diarrhea. Because malnutrition's impact on the incidence and severity of diarrhea may differ among diarrheas with diverse etiologies, study subjects should be grouped by diarrheal etiology. Studies should be designed to discriminate between malnutrition as a contributing cause of diarrhea and malnutrition as a result of diarrheal disease in specific ecologic settings.

Studies are needed to correlate supplementary food intake to functional outcomes. The usefulness of anthropometric criteria as a proxy for functional capacities is not clear unless frank growth failure is present. Results of such studies are expected to help identify the optimal duration of exclusive breastfeeding and the optimal timing for the introduction of other foods.

Studies are needed that examine physiologic parameters and the properties of foods that influence nutrient bioavailability and caloric density. The results of such studies should help identify improved formulations of foods and appropriate processing techniques for their production.

Studies and demonstrations are needed that examine alternative small and moderate scale food processes which will expand the utility of foods, increase storage stability, improve caloric density, reduce preparation time and minimize fuel use for cooking and hygiene purposes.