Well, I think it is really somewhat of a time and preference thing. If you are just raising them for enjoyment, and they aren't Cornish Cross, you can just have a constant feeder.
I am fairly new. At this time I have 38 (8 more tomorrow) 7 week olds. They have starter all day. Corn at night to warm them because they are new to the out of doors. And since right now I don't have a chicken tractor for them to use, I cut grass and give it to them 3 times a day. They go through about 5 gallons of cut green grass and other plants every day.... But they love it so much, and it makes the expensive feed last longer.
Nobody is ready for Jenny Craig yet.... (well, except me!
I have layers and they have access to their food whenever they want it...I have raised cornish-cross also, and they are to have their food taken away at night every night I think after the first week of age...
Most chickens should have access to feed at all times. Meaties are fed 12 on and 12 off. Like take the food away at seven at night and give it back at seven in the morning. This is done to help minimize leg problems and sudden death to which meaties are prone.