My two cents
Here's the skinny on mealworms. I used to raise these things and they fed on oats, ground up non-colored dog food, and a variety of vegetables/fruits. If you are just buying a pack from the store then they can be refrigerated and do not require additional food. The cold makes them go into a sort of hibernation and they can keep for months. Allow them out for a few hours a week and they may chow down or get some moisture.
I have heard reports of mealworms being too chitinous and causing impaction in young animals, but I have not experienced it personally. Mealworms are ok nutrition wise but they are much fattier than crickets so I wouldn't use them as a staple.
All of my animals are feeding on roaches, which have a higher meat to shell ratio, breed easily and without smell, and some sp. can reach 2+". If you're interested in how to do roaches pm me. I know a lot of people in the circuit so I can usually get you bugs at way below market.