Tegus are omnivores that need a mix of protein, vegetables, and fruit, with the exact ratio shifting as they grow. Hatchlings eat mostly insects, while adults transition toward a diet that’s roughly 60% protein, 30% vegetables, and 10% fruit. Getting this balance right is the single most important thing you can do to keep a tegu healthy long-term.
Diet Ratios Change With Age
A young tegu’s body is growing fast, and it needs protein to fuel that growth. Hatchlings and juveniles eat roughly 50% invertebrates, 20% vegetation, and 20% vertebrate prey (small whole animals), with the remaining portion coming from fruit. Insects should make up most of the protein you offer at this stage simply because of the tegu’s small size.
As an Argentine black and white tegu matures, its diet gradually shifts toward more plant matter. Wild adult Argentines eat 30 to 60% plant material (mostly fruit), 15 to 40% invertebrates, and 20 to 30% vertebrate prey. In captivity, a good rule of thumb for adult Argentines is 60% protein, 30% vegetables, and 10% fruit. Colombian tegus are more carnivorous and do well on about 90% protein and 10% vegetables throughout their lives.
Best Protein Sources
Insects should form the backbone of the protein portion at every life stage. Good staple feeders include dubia roaches, crickets, earthworms, superworms, black soldier fly larvae, hornworms, silkworms, and king worms. Wax worms and butterworms are higher in fat, so treat those as occasional additions rather than staples. Gut-loading your insects (feeding them a nutritious diet before offering them to your tegu) makes a real difference in the nutrition your lizard actually absorbs.
Beyond insects, low-fat options like cooked or boiled egg whites, fish, crayfish, and shrimp add variety without excess fat. Lean ground turkey works well mixed into meals, though it shouldn’t be the bulk of the diet. Cooked chicken pieces and small mice can be offered occasionally as treats or training rewards, but mice and rats are high in fat and shouldn’t become regular menu items.
Why Whole Prey Matters
Whole prey items like chicks, small fish, mice, and crayfish are nutritionally superior to processed meat because they contain bones, organs, and skin. This means a more complete nutrient profile, especially calcium. When you offer ground meat or muscle meat alone, you’re providing protein without the mineral balance a tegu needs. If you do use ground turkey or chicken, you’ll need to add calcium powder to compensate for what’s missing. Eggs served with the shell (raw or boiled) are another way to sneak in extra calcium naturally.
Vegetables and Fruits
For adult Argentine tegus, vegetables should make up about 30% of the diet. Dark leafy greens, squash, bell peppers, and other nutrient-dense vegetables are solid choices. The goal is variety over time rather than the same greens at every meal.
Fruit should stay around 10% of the total diet for Argentine tegus. Berries, mango, papaya, and melon are popular options. Fruit is naturally high in sugar, so it works better as a regular small portion rather than a large part of any single feeding. Many tegus love fruit and will happily eat it over everything else, which is exactly why you need to control how much you offer.
Calcium and Supplements
Calcium supplementation is non-negotiable for captive tegus. The calcium-to-phosphorus ratio in your tegu’s diet should be about 1.5 to 2 parts calcium for every 1 part phosphorus. The problem is that most feeder insects are naturally low in calcium and high in phosphorus, so you need to dust them with calcium powder before feeding. Coat insects generously, not lightly.
You can also improve your insects’ calcium content by gut-loading them with a high-calcium diet for 48 hours before offering them. Crickets fed a diet that’s about 12% calcium on a dry matter basis can reach a 2:1 calcium-to-phosphorus ratio on their own.
A reptile multivitamin can fill in gaps, but dosing is less precise than with calcium. A conservative approach, offering multivitamin once a week or every other week, is safer than overdoing it. Some keepers use a multivitamin without added vitamin D3, since their tegu gets D3 from UVB lighting instead.
What Happens Without Proper Calcium
When a tegu doesn’t get enough calcium, or can’t absorb it properly, its body starts pulling calcium out of the bones. This leads to metabolic bone disease, one of the most common and preventable health problems in captive reptiles. The bones become soft and brittle, leading to deformities, fractures, tremors, and difficulty moving. Diet is only half the equation: your tegu also needs proper UVB lighting, temperature, and humidity to metabolize vitamin D3 and actually use the calcium it eats. Without UVB, even a calcium-rich diet won’t prevent the problem.
Feeding Schedule by Age
How often you feed matters almost as much as what you feed. Young tegus should eat every day. Between ages 1 and 3, drop to every other day. Once a tegu passes 3 years old, feeding every 3 days is appropriate. For fully grown adults, some sources recommend feeding as infrequently as once a week, adjusting based on body condition. An overweight tegu should eat less often, while an underweight one may need more frequent meals.
Obesity is a genuine risk with tegus, especially adults. These lizards are enthusiastic eaters and will happily consume far more than they need. Monitoring body condition and adjusting frequency is more reliable than sticking rigidly to a schedule.
Hydration and Humidity
Tegus need a water source large enough to soak in, not just drink from. They’re strong swimmers and many genuinely enjoy soaking, so a heavy dish or small tub works well inside the enclosure. Some keepers offer a kiddie pool during supervised time outside the enclosure for enrichment.
Enclosure humidity should stay around 70 to 80%, with natural dips to about 50% during the day and spikes in the morning and evening. Heavy misting twice a day or an automatic misting system helps maintain this cycle. High humidity supports hydration, healthy sheds, and respiratory health. Fresh water should always be available, and expect to clean it often since tegus regularly walk through and defecate in their water.
Foods to Limit or Avoid
Mice and rats are high in fat and should only appear as occasional treats, not dietary staples. The same goes for fatty insects like wax worms. Ground meat without added calcium is nutritionally incomplete and can contribute to mineral imbalances over time. Any single food item that dominates the diet to the exclusion of variety increases the risk of nutritional deficiency, even if that food is otherwise healthy. The best tegu diet is a rotating one, with different protein sources, different vegetables, and consistent calcium supplementation tying it all together.