Eat it or wear it

I am not a native speaker. Give an idea of what 'eat it or wear' means

Does it refer to an over-decorated hat in which a hungry person sees sustenance, and the well fed sees decorative advantage at the races.

Maybe it's just the people I hang around. But I have heard this said by the cook to a reluctant diner. "I worked in the kitchen all day. Now, eat that spaghetti or wear it."