My 13 month old sub-adult eats about 20 or so bugs daily on average with greens daily. While my two year old adult male eats twice a week for insects, about 20 or so.. gets offered greens but rarely eats them.
An my two year adult female eats daily, about 20 bugs every day and greens daily. However in a few weeks she will slowly be switched to twice a weak. (She just laid eggs so shes recovering still).
As you see it sort of depends on the health state and age of the beardie,
I usually go by this feeding guide on how much to give normally.
All life stages eat 10-20 bugs a feeding.
1-4 months 3x a day.
4-12 months 2x a day.
12-20 months once a day.
20+ months twice a week at the least, every other day at the most.
Staple feeders - Crickets, locusts, grasshoppers, silkworms, black soldier fly larvae, dubia roaches, turkish roaches, possibly earthworms.
Treat feeders - Waxworms, hornworms, superworms, mealworms, butterworms.
Wax worms - once a week, 4-5 max.
Hornworms - every other day to every two days, 4-6 max.
Mealworms - every other day to every two days, 5-10 max. Only for beardies above 6 months.
Superworms - once or twice a week, 3-4 max. Only for beardies above 12 months.
Butterworms - once or twice a week, 3-4 max.
Daily greens- Turnip/collard/mustard greens, endive, and kale if added to a mixture of the other staple greens mentioned.
Fruit once or twice a week - Banana, strawberries, blueberries, blackberries, red raspberries.
For more food items -
http://www.thebeardeddragon.org/bearded
http://www.beautifuldragons.com/Nutrition.html
You want two supplements at the very least, a calcium and a multivitamin.
Generally beardies below two years need calcium 5x a week and multivitamins 2x a week.
However beardies above two years or at two years of age need calcium only 2-4x a week with
multivitamins 1-2x a week.
This depends on how your adult beardie is with diet, health, just laid eggs, is laying eggs, etc.