This prospective observational study examined associations between fat-free mass (FFM) and fat mass (FM) accretion during the first 1000 days of life and neurodevelopment in term-born, low-risk infants from Karachi, Pakistan. Using the deuterium dilution method to estimate BCIs and the INTER-NDA at 24 months (n=132), results showed that children with gross motor delays had significantly lower FFM at 18 months, while those with behavior problems had significantly higher fat% at 24 months. However, these associations were not significant after adjusting for covariates. Trajectory modeling indicated a critical period between 12 and 18 months where fat accretion influenced negative behavior scores. The findings highlight the need to balance neurodevelopment and metabolic risk in nutritional interventions.

Shabina Ariff, Almas Aamir, Aneurin Young, Laila Sikanderali, Arjumand Rizvi, Fariha Shaheen, Gul Nawaz Khan, Sajid Soofi, Michelle Fernandes