Dr. Gecko recommends feeding a  varied diet to leopard geckos.  A vast majority of the nutritional imbalances often seen in geckos result from a poor and/or unbalanced diets.  Feeder insects to consider as prey items could include appropriately sized: 

• Commercial house crickets (Acheta domesticus)
• Black field crickets (Gryllus domesticus)
• Mealworms (Tenebrio molitor)
• Superworms (Zophobas mario)
• Silkworms (Bombyx mori)
• Locusts (Melanopus spp.)
• Cockroaches (Blaberus cranifer, etc...)
• Wax worms (Galleria melonella)
• Pinky mice (for breeding females)

Why feed a variety of insects?

Each insect, in terms of nutritional quality, is comprised of varying levels of:

All of these work together to provide your gecko with energy, proper metabolic functioning, prevention of diseases and disorders, and much more.  Each of these are required in varying amounts which can be achieved by offering a varied diet.

There are other factors that one should take into consideration  when creating a well-rounded diet for their gecko .  Things to consider include:

For example, younger and still-growing geckos may have a higher protein requirement than already established adults. 

It is also important that you maximize/enhance the nutritional quality of the mealworms by offering them a high quality diet - this process is called gut-loading.  Here is a widely used and accepted gut-loading diet that can be used with several different insects.  As with humans, you are what you eat!

Most feeder insects have a poor calcium:phosphorous ratio which is why it is often recommended to offer them as part of a varied diet.