As an ectomorph, she finds it hard to gain weight even though she eats a lot.

ectomorph 是由前缀 ecto-（表示"外部"）和词根 -morph（表示"形态、形状"）组成的复合词，在体型分类学中特指"外胚层体型"，这种体型特征为瘦长骨架、代谢快、难以增重。