Green iguanas, like us, are omnivores, which means they can eat pretty much anything. Specifically it means that they can eat both plants and animals and thus the green iguana diet is neither wholly carnivorous nor herbivorous. When keeping green iguana then, you have the slight advantage of being able to feed your pet a great variety of different foods. However at the same time an omnivorous diet develops in a creature for a reason and normally means that they need a more varied diet in order to survive. It is your responsibility then to make sure that your green iguana’s diet is varied and gives it everything it needs.
The bulk of the green iguana diet, at least when kept as a pet, is likely to be made up of green leaves and plants, as well as some fruits. Examples of greens include spinach, collard greens, chicory greens and alfalfa. Dandelions also make a great staple in a green iguana diet, and are useful as they are easy to pick in fields or even sometimes down alley ways. Make sure that you dispose of any roots, of your plants and chop the greens finely. Wash the greens before you give them to your iguana to remove any pesticides etc that may be on them. This will help to ensure that your iguana gets a good amount of calcium, which is crucial for healthy bones and will also help with iron, antioxidants and other minerals.
Their protein meanwhile will be provided by eggs (hardboiled or scrambled) and insects (such as mealworms or crickets which can be bought as food from some pet stores). You can even on occasion feed your green iguana tuna or chicken, but again ensure it is well sliced. Protein is particularly important for a young green iguana diet to help it grow. After this point focus mostly on greens for the bulk of the diet but be sure to ring the changes to ensure they get everything they need.