Nutrient density, but not cost of diet, is associated with anemia and iron deficiency in school-age children in South Africa

Objectives: This study aimed to investigate the relationship of nutrient density and diet cost with anemia and iron deficiency (ID) in children. Methods: Dietary intake data of 5- to 12-y-old children (n = 578) from three independent studies in low-income communities were pooled. Nutrient densities were calculated using the Nutrient Rich Foods index and Nutrient Rich Diet index, with higher scores indicating more nutrient-dense foods and diets. Food prices and food intake data were used to calculate ratios of nutrient density to price for foods and diets. Descriptive and correlation analyses examined associations of nutrient density and diet cost with anemia and ID. Results: Most children (>50%) consumed starchy staples (100%), vegetables that are not vitamin A rich (63.9%), and legumes (58.1%), with mean NRF9.3 scores ranging from 31.9 to 56.3. Cheese, eggs, organ meat, fish, dark-green leafy vegetables, and vitamin A-rich vegetables and fruits had mean NRF9.3 scores ranging from 112.6 to 184.7, but each was consumed by less than a third of the children. Children with anemia or ID had lower NRD9.3 scores than children without (P < 0.001 and P = 0.039, respectively). Diet cost did not differ according to anemia and iron status, but nutrient-density-to-price ratio was lower in children with anemia than without (P = 0.001). Conclusions: Careful selection of nutrient-dense foods as substitutes for foods with lower nutrient density could make it possible for children to consume a diet richer in specific nutrients and help prevent anemia and ID without affecting diet cost.