They're not malnourished....
As for diet, I'm well aware of the dangers of filling them up with low nutrient food but I do give them dark leafy greens every day.... Their main diet is an 18% ruminant protein layer pellet. They also get a small amount of leftover cat food twice a week, and the hand fed treats are sunflower seeds with the shells on or dried mealworms.
They boss around the cat, so they can't be especially racist! He's 12 and not completely sure of these new beings. I was feeding them mealworms in my hand when the cat decided he wanted some but a chicken head was in the way. He bopped her on the head, she turned around, did the full wing spread and feather fluff, and chased him across the lawn! And then calmly returned for mealworms! Pecking order established