Three food pattern-based indices diagnose lactating women's nutritional inadequacies in Argentina: A clinimetric approach using diet quality indicators and breast milk biomarkers.

Diet is a health foundation that supports breastfeeding and enables lactating women's recovery. This study aimed to develop 3 valid diet adherence indices by clinimetric contrast with different parameters. We hypothesize that the 3 diet adherence-based indices are positively correlated with diet quality and milk biomarkers and directly related to calcium, fiber, and energy intake. A cross-sectional study recorded food frequency, anthropometric and dietary measures, and milk analysis to estimate correlations, sensitivity, and specificity (n = 284). Three reliable indices agreed by >75% with food frequency: macronutritional (MDI), phytochemical (PDI), and energetic (EDI), which correlated positively to the Fat Quality Index and Minimum Dietary Diversity for Women. MDI and EDI correlated negatively to the Healthy Plant-Based Diet Index (H-PBDI), whereas PDI correlated positively. MDI correlated positively to the protein-to-carbohydrate ratio, whereas EDI correlated negatively. Inadequate intakes of calcium, fiber, and energy were indicated by MDI <19, PDI <19, and EDI ≥19, respectively, in a sensitive and specific manner. Body fat was therefore positively associated with EDI. MDI was associated with increased protein and superoxide anion in milk, depending on its high protein-to-carbohydrate ratio and low H-PBDI. These indices allowed us to assess diet to diagnose maternal malnutrition promptly. Index validity was supported by significant dietary correlations and biological responsiveness. MDI and EDI promoted breast bioactivity and body adiposity, respectively, whereas PDI represented a healthier option.