Just wanted to add my disconnected thoughts on this:
Highly processed foods are not any better for the chickens than they are for humans. I rarely feed mine white bread or ready to eat cereal.
White rice is pretty much devoid of useable nutrients. Lots of people food has added sugar and salt that a chicken doesn't need.
Even in the winter, some bugs are available when the chickens scratch around.
My chickens are molting now and not eating much. I have been feeding them oatmeal and scrambled eggs, meaty leftovers and cat food. I think they would rather starve than eat the pellets I buy for them. Of course, by this time, they are spoiled.