What Do You Feed A Lizard?

What you feed a lizard depends entirely on the species, because lizards are not one dietary group. Some eat only insects, some eat only plants, and many eat both. Getting the category right matters more than any single food, since feeding a plant-eater insects or an insect-eater fruit can cause serious health problems over time.

Most pet lizards sold in the US fall into three broad diets: insectivores (insects only), herbivores (plants only), and omnivores (both). A green iguana is a strict herbivore. A leopard gecko is largely insectivorous. A bearded dragon is an omnivore that leans toward plants as it ages. Each needs a different plate.

Why the Wrong Diet Is a Real Problem, Not a Small Mistake

Lizards evolved to extract specific nutrients from specific foods, and their bodies do not adapt quickly when the food type changes. A herbivorous lizard fed mostly insects can develop kidney and bone problems, partly because its digestive system is built for fiber and its calcium-to-phosphorus handling assumes plant sources. An insectivorous lizard fed fruit and vegetables may get too much sugar and too little protein, and can slowly lose condition.

The mechanism is worth understanding. Many plant-eating lizards regulate calcium and phosphorus differently from insect-eaters. When the balance tips toward phosphorus, the body pulls calcium from bone. Over months this shows up as soft bones, tremors, or difficulty walking. This condition, called metabolic bone disease, is one of the most common preventable problems in captive reptiles. It is not a single disease but a group of related conditions tied to calcium, phosphorus, and vitamin D.

So the first question is never “what food is healthy?” It is “what does this species eat?” Everything else follows from that.

What Do You Feed an Insect-Eating Lizard?

Insectivores eat live prey, and the insects themselves need to be fed well before they are offered. This is called gut-loading, and it changes the nutritional value of the insect. A poorly fed cricket is mostly empty shell and water. A well-fed cricket carries more vitamins and minerals.

Common feeder insects include crickets, dubia roaches, mealworms, superworms, and black soldier fly larvae. They differ in fat, protein, and how hard they are to digest. Crickets and roaches are generally considered good staples. Mealworms and superworms are higher in fat and often used more sparingly, though opinions vary by species and life stage.

Insects should also be dusted with a calcium supplement. For many insect-eating lizards, a common approach is to dust most feedings with calcium and use a supplement containing vitamin D less often. The exact schedule depends on the species and whether the animal gets real sunlight or UVB lighting. No single schedule fits every lizard, and a veterinarian who treats reptiles is the right person to set one for a specific animal.

Water matters too. Many lizards will not drink from a bowl. They get moisture from prey or from misting. Desert species often need less standing water than tropical species.

What Do You Feed a Plant-Eating Lizard?

Herbivores need leafy greens as the base of the diet, not fruit. Fruit is high in sugar and should be a small part of the plate, if it appears at all. The core of a herbivore diet is dark, leafy greens.

Good staple greens include collard greens, mustard greens, turnip greens, dandelion greens, and escarole. These tend to have a favorable calcium-to-phosphorus ratio. Other vegetables like squash, bell pepper, and green beans can be added for variety.

Some foods commonly given to herbivores are poor choices. Iceberg lettuce is mostly water and has little nutritional value. Spinach and kale are debated because of their oxalate content, which can bind calcium. They are not necessarily dangerous, but they are usually not recommended as the main green.

Fruit like berries, melon, and banana is often used as a treat or to encourage eating. It should stay a small fraction of the diet. A plate that is mostly fruit is a plate that is mostly sugar.

What Do You Feed an Omnivorous Lizard?

Omnivores eat both insects and plants, and the ratio shifts with age. Young bearded dragons, for example, need more insects for growth. As they mature, plant matter becomes a larger share. This shift is well known among reptile keepers, though the exact proportions vary and are not standardized across all species.

For an omnivore, a typical plate mixes gut-loaded, dusted insects with chopped greens and a small amount of vegetable. Fruit stays limited. The same calcium and vitamin D considerations apply.

One trap with omnivores is feeding whatever the animal will eat. Many lizards will happily eat fruit, cat food, or table scraps. Willingness to eat is not the same as suitability. A lizard eating something does not mean it should.

How Do You Know If the Diet Is Working?

You judge a diet by the animal’s condition over time, not by a single meal. Signs that something is off include soft or bent limbs, difficulty moving, a swollen jaw, poor appetite, weight loss, or shedding problems. These can point to nutritional issues, but they can also point to other problems, so a veterinarian familiar with reptiles should evaluate them.

Routine veterinary care for reptiles is less common than for dogs and cats, but it exists. Many of the nutritional problems seen in captive lizards are preventable with the right diet and lighting. UVB lighting matters because many lizards use it to make vitamin D, which is needed to absorb calcium. A good diet without appropriate lighting may still leave an animal short on usable calcium.

This is one of the less obvious points about reptile nutrition: the food and the light work together. You cannot fully separate them.

Can You Feed a Lizard Human Food or Pet Food?

Generally, no. Human foods and dog or cat food are not formulated for reptiles and can create nutrient imbalances, especially in calcium and phosphorus. Some keepers have historically used dog or cat food for certain species, but this is not a recommended practice and is not supported by evidence as a safe long-term diet.

Occasional small amounts of certain safe vegetables may be fine for some species, but the default should be foods known to suit that species. When in doubt, leave it out.

Quick Reference by Diet Type

This table is a starting point, not a prescription. Species within each group differ, and life stage changes the balance.

What About Supplements and Water?

Calcium supplementation is standard for many captive lizards, especially those that do not get natural sunlight. Vitamin D supplementation is more delicate. Too little causes problems, and too much can also cause problems. This is a case where more is not better.

Water needs vary widely. Tropical species may drink from leaves after misting. Desert species may get most of their water from food. A shallow water dish is often offered, but many lizards ignore it. Watching for signs of dehydration, like sunken eyes or loose skin, is more useful than assuming a bowl is enough.

Why Species Identity Comes First

Before any food decision, confirm the species. Many lizards are sold under common names that cover several different animals with different needs. A misidentified lizard can be fed the wrong diet for years before problems appear. If you are unsure of the species, that is the first thing to resolve, ideally with a reptile veterinarian or a knowledgeable keeper.

Once the species is known, the diet follows a clear logic: match the food type to the animal, gut-load and supplement appropriately, provide suitable lighting, and watch body condition over time. None of this is complicated, but all of it depends on getting the category right first.