Many aquatic turtles, wood turtles, forest tortoises and lizards consume both animal and plant matter. Energy sources for omnivores such as Box Turtle and Bearded Dragons are a mix of protein, fat, and carbohydrates. Wild omnivorous reptiles tend to eat more protein and fat during juvenile growth than during adulthood (slow growth).
Wild bearded dragons eat prey when young and plants when older in captivity thrive when fed prey as juveniles, a mix of prey and salads during years of reproductive activity, then salads in old age “their salad years”. The shift from carnivores as juvenile to omnivorous as adults are observed in aquatic turtles, Bearded Dragons and other reptiles.