Initial body fat gain is related to brain volume changes in adolescents: A repeated-measures voxel-based morphometry...

Individuals with obesity versus those within a healthy weight range show brain volume differences, but it is unclear whether these differences reflect initial vulnerability factors or are secondary to weight gain.

One hundred sixty-two adolescents (M age = 15.3 ± 1.1; 81 females) with healthy weight were scanned at baseline. Sixty subjects (M baseline age: 15.2 ± 1.1; M follow-up age: 17.7 ± 1.2; 34 females) completed a second scan at 2- or 3-year follow-up. Voxel-based morphometry assessed global and regional gray matter (GM) and white matter (WM) volumes. Body fat percentage was assessed yearly over follow-up.

Baseline global/regional GM/WM volume did not predict body fat gain over follow-up. Adolescents who gained body fat showed greater decreases in GM volume in the putamen compared with those who showed loss of body fat. Adolescents who gained body fat showed greater increases in WM volume in the anterior cingulate cortex compared with those who showed stability of or loss of body fat.

Body fat gain versus stability and loss produce GM and WM volume changes, rather than baseline volumetric differences predicting body fat gain.