I don't believe you can overfeed Iguanas either as long as it is a natural diet. Forget about the prepared pet store food and feed mostly greens such as collard, turnip, mustard, escarole dandelion, etc. mixed with some spring mix. Add a topping of vegs. such as squash, beans, okra, etc. and then just a little fruit.

In the wild Iguana's can eat whenever and as much as they want. What makes people people fat and unhealthy is eating the wrong foods not too much food.

The books mentioned have good food suggestions. You can also check out Melissa Kaplan's site at http://anapsid.org/