Brain tissue volume changes following weight gain in adults with anorexia nervosa.

Objective: To measure brain volume deficits among underweight patients with anorexia nervosa (AN) compared to control participants and evaluate the reversibility of these deficits with short-term weight restoration.

Method: Brain volume changes in gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) were examined in 32 adult women with AN and compared to 21, age and body mass index-range matched control women.

Results: Patients with AN had a significant increase in GM (p = .006, η(2) = 0.14) and WM volume (p = .001, η(2) = 0.19) following weight restoration. Patients on average had lower levels of GM at low weight (647.63 ± 62.07 ml) compared to controls (679.93 ± 53.31 ml), which increased with weight restoration (662.64 ± 69.71 ml), but did not fully normalize.

Discussion: This study suggests that underweight adult patients with AN have reduced GM and WM volumes that increase with short-term weight restoration.