Birth weight, slowness in eating and feeding practices as independent determinants of rapid weight gain

Aim Our aim was to identify independent determinants of rapid weight gain in infants at 3‐4, 6, and 12 months of age. Methods A cohort study was conducted on Mexican term infants in public and private settings between March 2021 and May 2023. Rapid weight gain was defined as a ≥0.67 SD change in weight‐for‐age‐Z‐score from birth to 3‐4, 6, and 12 months of age. Maternal and infant characteristics were described, and infant feeding practices, appetitive traits, weight, and length were analysed at 3‐4, 6, and 12 months of age. Rapid weight gain predictors were determined using generalised linear regression models. Results In total, 168 infants were recruited (55% boys). Small‐for‐gestational‐age status increased rapid weight gain risk 1.5 times, whereas large‐for‐gestational‐age status represented a 20%–30% decrease. Slowness in eating decreased the risk by 10%. Protective factors were older maternal age and higher educational level, whereas formula feeding, early complementary feeding, greater food enjoyment, and satiety responsiveness increased the risk. Conclusions Small for gestational age, slowness in eating, and feeding practices can be rapid weight gain predictors across the first year of life.