I'm not sure where you read these things, but both are incorrect. I am going off of studies and information from breeders (many post here as well).
They MUST have live feeders 2-3 times a day when they are under a year. This provides sufficient protein for muscle and organ growth that is crucial within the first year of life.
They cannot have kale because it binds to calcium that they take in from their supplements and food, and it does not allow them to properly digest it. Spinach causes the same problem. Intake of calcium is extremely important, along with a proper
UVB bulb to process it, in the prevention of metabolic bone disease.
You can find mustard, collard, turnip, or dandelion greens at your local grocery store. Even the big chain grocery stores near me sell them.