I have 40 red sex links, 11 laying, 10 due to start laying around end of this month, and 19 due to lay around early may.
They go through 150lb food a month with approx. 50 lb of cracked corn as scratch.
I do limit what I put in each morning, I found that if I put to much in they don't want to go out and free- range, so I limit it and out they go, they get anywhere from 8 - 10 hours free ranging each day, when I bring them back in, in the evenings they get more food. Healthy hens/chicks, no wasted food.
They get scraps from the kitchen now and again, but I usually give this in the evening, otherwise they wouldn't want to go out.
It seems to work.