I use the Joshs Mix, (similar to that one, and I am about out of Joshs, and they are sold out, so may buy that one).
I also give them a "Beetle Jelly" blend that I made, its pretty much just apple sauce, with a ton of bee pollen, and a little bit of Spliruna and a dash of LoD.
I throw fruits and veggies in randomly, as we have extra.
I also use Agar Agar, Water crystals.
I dont go crazy about making sure that I add Fruits and Veggies. I add them when we have them, and I remember, because the food I am already giving covers the spectrum.
Even if I do add fruits and Veggies, my OH colony is so big, that its a fight to the death for it, so over half the roaches likely wont get anything. Variety is great and all, but after talking to a few of these Roach raisers, and gutload makers, its not really needed. I know, the cham eats it and "Variety", but the Variety is there already. The only reason to feed variety is to cover nutrient gaps, however that roach chow already does that.
Humans do not really benefit from variety either, they benefit from correct amounts of what they need, we want variety because we get bored. I had a friend in college, he is a Nutrition Coach, a professional body builder, and a nut job about health stuff. He eats the same exact meals, every single day, with the same supplements along with it, he still does it today. 90% of his meals consist of Chicken, Plain Grilled chicken, and Brown Rice, and Fruit and Grain cereal for breakfast. Every once in a blue moon, he would eat out with us, most of the time we would go to a pizza place ect, and he would bring a container with Chicken and Brown Rice and veggies lololol. No sauces, no drssings, nothing, Chicken, Veggies, Fruit, Grain, EVERY SINGLE DAY. I would die!
All this is to say, I think that diet is fine, and adding fruits and veggies when you can is fine, but its not the end of the world

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I am not saying dont vary insects, as that is a different story. A cricket will eat this chow, and process it differently and provide different nutrients from it. Insects should be varied, and like I said, throw in fruits veggies when you can, or remember, but you dont have to go out of your way to make sure they have a different veggie everyday ect.
Nor and this is important! Should roaches be fed everyday. Especially a high protein diet like this. They store excess protein and can cause your animal to get gout. So how do you stop this? By allowing them to utilize that excess protein, they store it so they can use it later, and burn it while they lack food source, as roaches can go months without food. I feed my roaches, this grain and the bee pollen mix, 2x a week, and throw fruits veggies whatever, whenever. They will survive and breed, and be happy just fine like this, and it gives them time to burn off excess protein stores, so that they dont build it up. If you feed them everyday, they will eat everyday, and get fat and never burn off those stores.