Abstract
BACKGROUND: Childhood obesity is linked to altered brain functional connectivity (FC) in brain gray matter (GM), with potential implications on changes in cognition function. This study investigates white matter – white matter (WM-WM) and WM-GM FC differences between children with normal-weight (NW) and overweight/obese (OW/OB) using functional Magnetic Resonance Imaging (fMRI). METHODS: Resting-state fMRI data from 68 children aged 10–12 years (32 OW/OB, 36 NW) were analyzed. FC matrices were constructed using predefined WM and GM region of Interest (ROI). Group differences and correlations with body mass index (BMI) were analyzed using t-test and Pearson correlation. RESULTS: The OW/OB group exhibited increased WM-WM FC between the middle cerebellar peduncle (m.CBLP) and right uncinate fasciculus (r.UF), which was also positively correlated with BMI (R = 0.47, p = 0.0001). Meanwhile, reduced WM-GM FC was observed between the body of the corpus callosum (b.CC) and right dorsolateral prefrontal cortex (r.DLPFC), which was also negatively correlated with BMI (R = -0.44, p = 0.0002). CONCLUSIONS: Our findings suggest that childhood obesity is associated with changes in WM-WM and WM-GM FC, potentially impacting motor coordination (via m.CBLP-r.UF) and executive function (via b.CC-r.DLPFC), contributing to cognitive regulation differences. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12883-026-04804-w.