feeding feeders?

What do they feed king worms to get them big?
I bred some and got small mealworms from kingworm beetles?
Can you feed whatever you feed the worms to other things like superworms? Mice?

Feeding mice, whats good to feed them to make them big and meaty?
I have been giving them dog cookies for extra protien.

The best thing to feed pretty much any rodent is a lab block. I think the most popular brand here is probably Mazuri, but some others are Kent, Harlan-Teklad, Purina LabDiet...there are a ton. Usually this has to be special ordered from a local feed store, or order online. Online is usually not a good idea, since shipping will cost just as much as the feed.

I don't have any experience with any worms, so I don't even know where to start.