Possibilities
It was designed in that way to prevent any citizen from taking too much while there are others who have less to survive on.
Whoever it may be, be there the noble born, the high ranking citizens or even the lord of the city and the rest of his family members for that natter, none of them were made an exception to the rule passed down by the three of them.
When it was morning, every citizen who desires to be fed will have to queue in a line that conducts the distribution of resources to them.
Once your share is taken, you are to move away from the line and never come back for a second until the next day.
There are some who have tried to outsmart the rules by joining the line after they have already been given their ration.
For those ones who dared to go against the will, they were easily caught and made an example of by having them exempted from any supplement for ten straight days.