RESUMEN
BACKGROUND: The first 2 years of life represent a critical phase for growth and development, with the quality of the diet at this stage having repercussions throughout adulthood. The present study aimed to develop an Index for Measuring the Quality of Complementary Feeding (IMQCF) for infants, as well as to evaluate diet quality and its effects on the nutritional status of preterm infants. METHODS: This cross-sectional study was conducted at a Brazilian University Hospital. The data were extracted by care protocol of outpatient preterm infants at 2 years of corrected age (CA). Dietary data were collected from 24-h recalls. The diet quality was assessed by the IMQCF composed of nine items based on a Brazilian Food Guide for children aged <2 years. Response options were scored 0-100, with scores closer to 100 representing a better quality diet. Association with growth indicators (Z-scores for weight- and length-for-age (WAZ and LAZ) were evaluated via tests of mean difference and multiple linear regression. RESULTS: The median complementary feeding (CF) score was 72.2 (61.1-77.8) A shorter breastfeeding duration or infant formula use and the early introduction of wheat-based foods, ultra-processed foods and cow's milk in the preterm's diet were the main factors interfering in the adequacy of diet. There was an association between the quality of the diet score and WAZ (0.44; 95% confidence interval = 0.03-0.85; P = 0.03). CONCLUSIONS: The introduction of poor quality food in the first 2 years of life interfered with the CF quality of preterm infants and can affect nutritional status at 2 years of CA, possibly in the long term.