Abstract Background: Undernutrition in early childhood has historically been considered irreversible after 2-3 years of age and has been associated with morbidity and mortality over the short-term and poor economic and cognitive outcomes over the long-term. We used longitudinal data to determine which factors are associated with positive changes in absolute and relative differences in height and weight from the WHO Growth Standards from 24 to 60 months of age.Methods: Across six MAL-ED sites, 942 children had anthropometry data at 24 and 60 months, as well as information about socioeconomic status, maternal height, gut permeability (lactulose-mannitol z-score (LMZ)), dietary intake from 9-24 months, and micronutrient status. Anthropometric changes were categorized as positive changes in height- or weight-for-age z-score (HAZ, WAZ) or their absolute difference from the growth standard median (HAD (cm), WAD (kg)), as well as recovery from stunting/underweight. Outcomes were modeled using multivariate linear regression.Results: Forty-three/34% of the children who were stunted/underweight at 24 months were no longer stunted/underweight at 60 months, Among the sites, 64-92% of children had positive changes in their HAZ, whereas 25-60% had positive changes in HAD. Linear regression models indicate that female sex (-0.21 HAZ (95% CI -0.27, -0.15); -0.75 HAD (-1.07, -0.43)) and mean LMZ (0-24 months) (-0.10 HAZ (-0.16, -0.04); -0.47 HAD (-0.73, -0.21)) were negatively associated with change in both metrics, and maternal height was positively associated with both (0.09 HAZ (0.03, 0.15); 0.45 HAD (0.15, 0.75)). Similar relationships were identified for change in WAZ and WAD. Dietary protein density was negatively associated with change in WAZ and WAD (-0.05 WAZ (-0.09, -0.01); -0.11 WAD (-0.21, -0.01)), and mean plasma transferrin receptor concentration was positively associated with change in WAZ and WAD (0.02 WAZ (0.0, 0.04); 0.04 WAD (0.0, 0.08)).Conclusions: While children in the MAL-ED study demonstrated recovery from stunting and underweight from 24-60 months of age, they also lost additional centimeters and grams when compared to the WHO median references. Given the similarities in the factors associated with changes in HAZ and HAD (and WAZ and WAD), both can be used to characterize catch-up growth during childhood.Funding Sources: The MAL-ED study was supported by the Bill & Melinda Gates Foundation, with grants to the Foundation for the NIH and NIH/FIC.