French

a group of soldiers or workers can only fight or function effectively if they have been well fed

给养充足的士兵（或工人）才能很好地战斗（或工作）

on a full (或 an empty) stomach

after having eaten (or having not eaten)

饱（或空）着肚子

I think better on a full stomach.

我吃饱了才能更好地思考。

a strong stomach

an ability to see or do unpleasant things without feeling sick or squeamish

（看或做讨厌的事时）坚强的性格