"Empty bags do not stand" is the literal English translation of this Haitian proverb.
In Haiti, people use 'sak' (bags) for many purposes. They use plastic, carton, and clothe ones. They are used in to put goods, merchandise, crops, harvest, food or any personal stuff so that they can transport them and hide them from the sight of people.
As we all know, a 'sak' (bag) cannot stand but itself or stay upright if it is not full, half full or without something in it. If empty, it will lay on the ground.
Haitians use this proverb to say that in the same way a 'sak' (bag) cannot stand by itself if it is empty, people cannot do anything or have strength and energy to do anything or even stand up if they are hungry.
This proverb is used whenever someone is called to do something and he/she is hungry or when he/she gets weak after trying to do some kind of work with an empty belly. So you know immediately that they really need something to eat. And you would rather give them something to eat so that they can recover in strength and energy.
So remember: 'Sa k vid pa kanpe'.