While it's not a good idea to not feed them, it's also not a good idea to only feed them unhealthy bugs like supers, waxworms, butterworms and hornworms.
I didn't know that hornworms aren't healthy. Mine has been eating mostly just those the last two weeks. He has decided he doesn't want dubia; will sometimes have a superworm (which I know isn't the most nutritious. I did get some silk worms today. I ordered 50 and they sent me 120 so I'm going to see if I can get some to reproduce. I had just ordered hornworms which were on special buy 2 get one free. I'm going to be over run with worms!
I have had good luck with hornworms as a main live food staple for Beardies. Lord knows that Ragnar loves them and he is growing like crazy. I alternate dusting them with Calcium and Reptile Vitamins. Not sure how Hornworms differ nutritionally all that much from Silkworms. I feed Ragnar Silkworms whenever I can get them. He will eat Dubias when he wants to (and not, when he doesn't want to.)
I just recently found out locusts and roaches are illegal in canada? If that's true then I can't fault you for feeding hornworms or supers as your really lacking a staple protein feeder besides crickets which everybody hates lol.