Flannagan KS, et al. - Researchers analyzed the alterations in body mass index (BMI)-for-age Z scores (BMIZ) through adolescence in relation to serum polyunsaturated fatty acids (PUFA) biomarkers in childhood. Participants were 418 children from Santiago, Chile, in whom, serum PUFA was quantified at ages 5 and 10 years. Measurements of BMI at 5, 10, and 16 years were obtained. They found inverse link of serum docosahexaenoic acid, at age 5 years, with BMIZ change from ages 5 to 16 years. A nonlinear positive association of arachidonic acid (AA) at age 10 years, with BMIZ change from ages 10 to 16 years was evident. They also noted that alteration in AA and the Δ5-desaturase (D5D) activity index between 5 and 10 years were each positively related to BMIZ shift from ages 10 to 16 years. An inverse link of change in eicosapentaenoic acid with the change in BMIZ was also identified. In this study, less BMI gain through adolescence was observed in correlation with serum long-chain n-3 PUFA in middle childhood, whereas greater BMI gain was reported in relation to AA and D5D activity.