Here are Olimpia Martinotti's lists of great ingredients to feed your gecko's bugs & worms:
Best: mustard greens, turnip greens, dandelion leaves, collard greens, escarole lettuce, papaya, watercress, & alfalfa.
Good: sweet potato, carrots, oranges, mango, butternut squash, kale, apples, beet greens, blackberries, bok choy, & green beans.
Dry food: bee pollen, organic non-salted sunflower seeds, spirulina, dried seaweed, flax seed, & organic non-salted almonds.
Avoid as much as possible: potatoes, cabbage, iceberg lettuce, romaine lettuce, spinach, broccoli, tomatoes, corn, grains, beans, oats, bread, cereal, meat, eggs, dog food, cat food, fish food, canned or dead insects, vertebrates.
I use a vitamin powder from Repashy brand"I just feed them carrots. Occasionally patotoas, but not often"
May I ask where you are from?
We are what we eat & so are geckos! Carrots are fine, but really not potatoes!
It is important to feed Arnie's bugs & worms a high quality dry diet 24/7/365 days per year. This diet/food should be in powdered form so crickets can easily eat it. Some suggestions for the dry diet are Repashy's Bug Burger or Repashy's Superload.
Feeding your insects & worms 24/7/365:
The term "gut loading" causes some confusion.
One meaning = feeding insects & worms a high quality dry diet 24/7/365 + providing high calcium/low phosphorus leafy greens like collard, mustard, turnip greens, & pesticide-free dandelion flowers/greens. Serve veggies in a separate ridged lid off to one side to add vitamins, minerals, & moisture to their diets. Some keepers consider this a maintenance diet! This diet is passed on to your geckos.
We create more nutritious insects & worms by feeding them a balanced DRY diet 24/7/365 days per year.
Then, if you wish, supplement that dry diet with veggies from the following lists.