Correlation between brain circuit segregation and obesity

•In voxel-based morphometry, the obese patients showed altered gray matter volumes in the amygdala, thalamus and putamen.•The obesity group showed increased functional connectivity in the bilateral anterior cingulate cortex.•The obesity group showed decreased functional connectivity in the frontal gyrus of default mode network.•The obesity group also exhibited altered ALFF and ReHo in the prefrontal cortex and precuneus.•In the graph theoretical analysis, the obese patients showed a shift toward randomization in their functional networks.