The amount of pineapple to feed your iguana depends on size and weight. A good rule of thumb is to give them one slice of pineapple for every two ounces of body weight. For example, give them two slices of pineapple if your iguana weighs four ounces. This means giving a few cubes of about 25-50 grams. Moreover, the amount will also depend on the health status of your iguana. Give less pineapple if your pet is suffering from a health condition. The status of the pineapple will also affect how much you give them; for instance, if the pineapple is acidic or unripe, give only small amounts.