You want to gutload with nutritional foods. Carrots only supply the vatamins and minerals that are found in carrots, and a some sugars and fiber I guess. They also need protein and some fat. You want to pass that nutrition on to your animals.
Here's what I do/did for mealworms and supers. Ratio of 3 parts bedding to 1 part gut load. I would use wheat bran for bedding, super cheap ($1 a pound most places). Mix it up and put your worms in it. Every couple days add some carrot, potato, apple, etc. for moisture. If you see some of the bedding mold, keep the moisture down by adding more air circulation and destroy the part of bedding that has molded.
If possible, I'd switch to roaches if you can. They really made a difference for my reptiles.