In industrial facilities pre-peak (92%+ rate of lay) Leghorn type (white egg layers) get 23 to 24 lbs of feed per hundred per day. That is 3.75 ounces approximatley. Industrial Brown egg layers (those would be ISA Browns and others commonly known as Golden Comets) eat slightly more because they are bigger and produce greater egg mass. They are fed as much as 25 lbs per hundred per day which is about 4 ounces per bird per day.
As the birds pass their peak production point they will not eat as much feed but still more than they need for the rate of lay. The Leghorns will put on a little size and fat but not as much as the brown egg layers.
In the industrial situation we limit feed post peak because of the unwanted weight gain and the hen's ability to lay an increased size egg. Neither of which is wanted.
Remember that this is the only feed these birds get and it is strictly formulated to address all factors- especially cost.