First of all... I love Bob Hope!
My oldest chicken is going to be 11 in September. I have never put any of my chickens on a strict diet. I have a feeder that holds 30 lbs of feed and I fill it up with layer mash (and occasionally I'll mix in some cracked corn or oats...) and they will eat what they like when they like. "Jewel" my oldest hen (she is a Black Sex Link) loves cat food and if we don't keep her off of the back porch everyday her lunch will consist of a cup or two of Kit & Kaboodle
We typically give the whole flock some table scraps everyday (this could be anything). And they all get some peanuts or oats at least once a week.
Our Black Australorp hen "Bibby" is absolutely spoiled rotten. Every afternoon without fail (she is very faithful) she'll come walking up to the front porch, and beg and beg until someone comes out and throws her a handful of something (her favorite treat has always been rolled oats).
All of our chickens free range dawn till dusk, so at the end of the day their crops are bulging to no end
So, to sum it all up: Treat your chickens if you like, just make sure their 'feed' doesn't consist of potato chips or crackers. And that they always have access to a good healthy feed