An army marches on its stomach

Proverbial Meaning: One (or a group) needs food in order to complete a task or function efficiently.

Literal Origins: Food is an important consideration for an army general, being one of the greater expenses and also the most important aspect of an army. Without food for the troops, no amount of guns, bullets and technology are of any use. Soldiers most be fed and maintained in order to fight properly.

Common Usage: This is a well known proverb that is often spoken word for word either to encourage workers or a team set to a task to eat some food, or as an excuse by someone who wishes to eat food before they can be prodded into doing some work.