When lizards are in the wild they often consume a lizard diet that is composed of many kinds of insects, small mammals, fish, and plants. Depending on the species, they may even need one specific insect as opposed to a variety. When you have a pet lizard you need to feed him as close as you can to what he eats in the wild. Any big change in lizard diet and the lizard will not survive.
Make sure you research everything you can about a lizard diet before you bring one home. Some lizards are insectivorous (they eat insects), herbivorous (they eat plants), or omnivorous ( they eat both plants and insects or other meat). The higher the metabolic rate, the more times a lizard will need to eat. Since many lizard enclosures require heating with a thermostat that makes it hot during the day and cooler at night, this heat will require that your pet lizard eat at least once a day.
If your pet lizard eats insects, the first lizard diet to try is crickets, cockroaches, and other insects that have been caught in the wild. Live crickets can be bought at most pet stores and you should obtain some the same day as you purchase your lizard. If you start off with around a half dozen the first day you then determine if he needs more or less than this number. A lizard diet must also have the proper size insects. This is determined by the length of space between across the bridge of his nose. You should try to keep insects in his diet this size or smaller.
A lizard diet composed entirely of crickets can get a bit boring so you should try varying it with mealworms and waxworms. These are beetles who are still in the larval stage and not yet developed into adult beetles. These are also available from pet stores. With a captive lizard you are also going to have to give him vitamin and mineral supplements, which is accomplished by dusting the insects before giving them to the lizard. These can contain calcium with or without vitamin D3.
Without proper vitamin and mineral supplementation, a lizard will develop metabolic bone disease. If they get this disease their bones will disintegrate to the point that they will be unable to move. You should feed your lizard fresh insects caught in the wild whenever you can. This can be done with a trap or a net. Some lizards should never be kept as pets because their diet is impossible to maintain. One of these is the horned lizard who eats nothing but ants.
If your pet lizard is a vegetarian, give him plenty of veggies with a high nutritional value. Make sure to finely chop the lizard diet so that he cannot eat out one kind of vegetable and leave the others. Many lizards are attracted to the color yellow so yellow vegetables are a good choice. Other vegetables that are good for lizards include broccoli, avocado, cabbage, turnip greens, celery, dandelion greens, Swiss chard. Bok choy, cantaloupe and blueberries
Most lizards that eat both meat and plants are of the very large variety that most people would not have as pets, such as monitors and tegus. Many zoos do have these varieties. They are fed special canned commercial diets which are supplemented with insects and pre-killed baby mice.
Remember that temperature is vital to a lizard diet. They will not be able to digest their food less the temperatures are warm--between 85 and 105 degrees depending on the type of lizard. At other temperatures, chances are your lizard will stop eating altogether.