Early Caloric Adequacy and Nutritional Recovery in Children Hospitalized with Bronchiolitis

Background/Objectives: Feeding difficulties are common during bronchiolitis hospital-ization and may lead to reduced caloric intake. Evidence evaluating the relationship between caloric adequacy and hospital length of stay (LOS) remains limited. We aimed to characterize daily caloric adequacy during bronchiolitis hospitalization and evaluate its relationship with LOS. Methods: An ambispective cohort study including children younger than 2 years hospitalized with non-severe bronchiolitis between 2013 and 2023 was conducted at a tertiary hospital. Daily caloric adequacy was defined as the percentage of caloric goals achieved according to WHO/FAO recommendations. Total caloric intake included formula feeding, breastfeeding, complementary feeding, and intravenous fluids. Breastfeeding intake was estimated using a published probabilistic model. As-sociations between caloric adequacy and LOS were evaluated using Spearman correlation analyses. Results: A total of 613 patients were included, with caloric intake data available for 607. Median LOS was 5 days (IQR 3–7). Lower caloric adequacy during the first days of hospitalization was associated with longer LOS. Hospitalization day 2 showed the strongest early association with LOS (ρ = −0.228; p < 0.001). Patients with LOS >6 days did not achieve ≥80% caloric adequacy until day 3, whereas those with LOS ≥9 days reached this threshold only by day 6. The association remained significant mainly in children younger than 12 months and in those with moderate acute malnutrition at admission. Conclusions: Early caloric adequacy was associated with LOS in children hospitalized with bronchiolitis. Achieving adequate caloric intake during the first 48 hours may represent an important early nutritional target.