Is prolonged breastfeeding associated with malnutrition? Evidence from nineteen demographic and health surveys.

BACKGROUND: A growing body of literature suggests that prolonged breastfeeding (typically defined as beyond the first year of life) may be a risk factor for malnutrition.
METHODS: To examine the extent to which continued breastfeeding is a risk factor for malnutrition, we used multiple regression techniques to relate current breastfeeding status to weight and stature in children < 36 months old whose mothers participated in one of 19 Demographic and Health Surveys (DHS) conducted between 1987 and 1989.
RESULTS: The data from 9 of 11 countries outside sub-Saharan Africa (SSA) indicated that among older children, those still breastfed are shorter and lighter than those no longer breastfed. These differences, which reached statistical significance in five countries, become apparent at 12-18 months of age. In contrast, in five of eight SSA countries, younger still breastfed children are significantly shorter and lighter than those no longer breastfed, but, the differences are largely diminished among older children. These basic patterns were not altered by adjustment for family sociodemographic characteristics, health care utilization, and recent child illness.
CONCLUSIONS: Important differences in nutritional status associated with continued breastfeeding are observed throughout the developing world, and are not likely due to confounding by family sociodemographic characteristics, health care utilization or recent child illness. A unifying interpretation of the observed relationships is that child size is somehow related to the decision to wean, and that whereas in SSA, the biggest children are weaned first, in non-SSA countries, the smallest children are weaned last.