Validation of the Healthy Complementary Feeding Practices Index: A Novel Approach for Assessing Infant Feeding in Mexico

Objective To develop and validate the Healthy Complementary Feeding Practices Index (HCFPI), a novel tool designed to assess adherence to Mexico’s national dietary guidelines and inform the design of interventions to prevent malnutrition in infants aged 6–24 months. Methods The HCFPI was constructed using a literature-based selection of components, indicators, and scoring criteria. Content validity was evaluated using the Delphi method with experts. Internal consistency (Cronbach’s alpha) and concurrent validity with dietary intake were examined in a cross-sectional sample from a Mexican birth cohort at 6, 12, and 24 months. Results The HCFPI comprises 13 components and 15 items that reflect key CF dimensions, and it achieved “acceptable” expert consensus during content validation. The index demonstrated “acceptable” internal consistency (α = 0.70) and meaningful correlations with optimal Complementary Feeding (CF) practices, such as breastfeeding, the timely introduction of solids, and the avoidance of both unhealthy salty foods and follow-up formulas. Furthermore, higher HCFPI scores were associated with better dietary quality, including higher fiber intake, greater protein and vitamin B12 adequacy, and lower added sugar intake. Conclusion The HCFPI is a valid, reliable, and practical tool for evaluating adherence to CF recommendations and dietary quality in young children. Its framework offers a model that could be adapted to create similar indices in other countries using evidence-based national dietary guidelines.