de Fluiter KS, van Beijsterveldt IALP, Breij LM, et al. - This cohort study was undertaken to determine if a rapid increase in fat mass percentage (FM%) in the first months of life is correlated with higher trajectories of body fat mass during the first 2 years of life. Four hundred one healthy, term-born infants of the Sophia Pluto Cohort Study was analyzed. Participants were born from January 7, 2013, to October 13, 2017. The authors discovered that only the change in FM% in the first 6 months of life was linked to more adiposity at age 2 years. During the first 2 years of life, infants with a rapid increase in FM% had higher trajectories of FM% and FM index. Such results tend to support a critical window for adiposity programming in early life.