Good nutrition is important for good health. Good nutrition is; variation, food supplements, fresh water, offered in the right quantities and rich in nutrients. Offering live food at the same time gives the necessary exercise (make them hunt their food for exercise).
Bearded dragons are omnivores and eat both animal and plant foods. An adult bearded dragon eat about 40% live food and 60% fruit and vegetable.
Also, there are special pellets for bearded Dragons for sale. Feeding pellets is become increasingly popular because it's easy to feed and dosing. Not all bearded dragons like to eat these pallets, because the animals do not recognized it as (natural) food.