I know I won't be feeding them any thing else... It was just too much temptation to watch them eat something fun. As far as vegetation goes... my garden is over run with weeds rather than grass. I have pulled up half the vegetation many times trying to give the grass more of an upper hand. I am not worried about the grass, just the raised veggie bed's. Plus my girls will be caged in their pen unless we are there to supervise. They will get scraps, and plenty of bug hunting and I don't care if they eat all the grass and the weed's with it. They just need to leave my spinach alone! I don't plan on eating my girls, they are family now. So I really don't care if they get fat as long as it won't make them miserable.
Some of my chickens were special and got named, some didn't.
I named a turken: Joey, and it ended up being a girl, so she became Joie.. ha ha And then there was Hortense, a Cochin, with so much personality.
Everyone knew these chickens by name.
My husband currently has a white rooster, that he calls Whitey.
We have an overload of roosters and when I talked of getting rid of all roosters, to get rid of fighting chicken genes, he said, Not Whitey! ha ha
His Whitey is pretty mellow, I haven't seen him fight with anyone, so okay, deal!
Chickens won't really get fat on bugs and vegetation, it is the over feeding of grains and bread (grains processed) that leads to them getting too fat. But, they are growing now, so keep plenty of food, water, and veggies in front of them.
Ozark Lady - oh yes yes yes, I think they would peck my eye's out if I took their food away. The 3 big girls (2 barred rocks and 1 road island red) eat like they were darn near starved to death! Every 5 minutes they wake up from a nap and eat for 2 minutes, stretch, drink water, maybe peck at something scratch around and settle in for another nap... (oh to be one of my chicks ) I don't know what will happen if my girls turn out to be boy's.... I won't be able to eat them.... and I won't be able to give them to someone that will eat them.... sooo... lol Houston... we have a problem lol. I read this AM that girls develop feathers faster than boy's and my 3 big girls popped out tail feather's over night! So were hopeful. What is the first sign of a roo rather than a hen?
At this point the only guaranteed way to sex them is to look in the vent. The Americauna / Aruacana pullet will stay a wheat color.. the cockeral will develop into bright shades starting at 2 or so months old. Rhodies and barred rock pullets and cockerals look the same other than size and the comb. The Rhode Island cockeral will develop significant tail plumage though.
Had a Rhode Island cockeral that killed a few hens as he and the Americauna would be in competition in the same coupe for the pullets... I was selling pullets as I was downsizing and no one wanted mr rooster... So I tossed him in a feed sack, tied it shut and he was a freebie to the next person that stopped to buy pullets... Gave them a couple of pullets for free but in return they had to take mr rooster... He was a big boy too... My Americauna is 3 years old now... his spurs are almost 2 inches and he's broken both off at least once... He's developed a mean disposition as of late... You get near him and he flares and tries to spur you... He's no match for my boot though.
Since you are going to keep your chickens penned for the most part you will have to feed a consistent diet of grain as there will literally be no vegetation in or within beak range of the pen... It will be dirt... period... a good layer crumble, pellet or mash... 16% at a 50 / 50 mix with cracked or whole corn is a good feed staple.. Straight 16% and you'll need a ball peen hammer to crack the shells.. I never fill a feeder... Just what I want them to consume a day... Anything they don't eat the barn rats and mice take care of...
When I was a kid, my mom kept yard run chickens in the city. She had a small coop for them, but no fencing of any kind. They ate table scraps just like the dog ate. When one or more would start acting a little puny, mom would add a laundry product called "Blueing" to their water. It usually worked. I have no idea if "Blueing" is still available. It made whites whiter when added to the laundry water.
I had a pet rooster that followed me around like a dog. We lived near some busy railroad tracks. If a hobo hopped off a rail car and somehow found himself in our yard at night, he was quickly attacked by a white tornado with feathers. I've actually heard them run from our yard screaming because they had no idea what was after them in the dark.
It was just too much temptation to watch them eat something fun. As far as vegetation goes... my garden is over run with weeds rather than grass. I have pulled up half the vegetation many times trying to give the grass more of an upper hand. I am not worried about the grass, just the raised veggie bed's. Plus my girls will be caged in their pen unless we are there to supervise. They will get scraps, and plenty of bug hunting and I don't care if they eat all the grass and the weed's with it. They just need to leave my spinach alone! 
I don't plan on eating my girls, they are family now. So I really don't care if they get fat as long as it won't make them miserable.
) I don't know what will happen if my girls turn out to be boy's.... 
I won't be able to eat them.... 
and I won't be able to give them to someone that will eat them.... 