Bearded Dragon Diet Guide: What to Feed, What to Avoid, and How Much
A bearded dragon's health is built almost entirely at the food bowl. Get the diet right — the proportions, the supplements, the foods you keep out — and most of the scary reptile problems simply never show up. Get it wrong and you're managing obesity, metabolic bone disease, or impaction down the line. This is the practical feeding guide I'd hand a new keeper: what to feed, what to avoid, and how it changes as the dragon grows.
The one idea that runs everything: the ratio flips with age
Bearded dragons are omnivores, but how omnivorous depends entirely on age. Babies are protein machines; adults are mostly salad eaters. If you remember one thing, remember that the insect-to-plant ratio inverts as the dragon matures.
- Hatchlings & juveniles (0–6 months): roughly 70–80% insects, 20–30% greens. Feed 3–5 times daily. They're growing fast and need the protein.
- Sub-adults (6–18 months): moving toward 50/50. Feed about twice a day. Start emphasizing variety in vegetables.
- Adults (18 months+): roughly 75–80% vegetables, 20–25% insects. Feed once daily or every other day. Fruit stays a small treat (10% or less).
The most common diet mistake I see is feeding an adult like a baby — endless insects — which produces a fat, sick dragon. Let the ratio flip.
Staple insects: the protein side
Live insects are the protein engine, especially for young dragons. Good staples:
- Discoid roaches (Blaberus discoidalis) — high protein (~20%), moderate fat, soft and low-chitin, easy to digest, and they don't climb smooth walls. An excellent staple and the one I build around, particularly in regions where dubia roaches are restricted.
- Crickets — solid protein, cheap, widely available; downsides are smell, noise, and a talent for escaping.
- Dubia roaches — nutritionally similar to discoids; just check that they're legal where you live (they're restricted in Florida).
- Black soldier fly larvae (BSFL / "calci-worms") — the rare feeder genuinely worth keeping for its calcium; great for hatchlings.
- Silkworms — soft, nutritious, easy to digest; a nice rotation item.
- Hornworms — mostly water; a hydration treat, not a staple.
Whatever you choose, source clean. Wild-caught insects can carry pesticides or parasites. A reliable supplier matters, and All Angles Creatures stocks live feeder insects sized for every life stage. Two habits multiply the value of any feeder: gut-load it (feed the insects well for 24–48 hours before offering them) and dust it with calcium.
Vegetables: the foundation for adults
Greens and vegetables should dominate an adult's diet and be introduced early in juveniles so they learn to eat them.
Best staple greens: collard greens, mustard greens, dandelion greens, turnip greens, endive, and escarole — calcium-rich, nutritious, easy to digest.
Good additions for variety: butternut and acorn squash, bell peppers, and carrots, offered alongside the leafy base.
Skip these:
- Spinach, beet greens, and chard — high in oxalates that bind calcium and make it unavailable.
- Iceberg lettuce — basically water and fiber with no real nutrition.
Chop everything to bite-size, wash it to remove pesticide residue, and rotate variety so the dragon gets a broad mineral and vitamin spread.
Fruit: a small, occasional treat
Fruit is fine in moderation — think 10% of the diet or less — because the sugar adds up fast. Safe choices include blueberries, peeled apple (no seeds), papaya, strawberries, mango, and melon. Keep it occasional and keep portions small; fruit is a garnish, not a food group.
Foods to avoid — including the genuinely dangerous ones
Some foods aren't just unhelpful, they're harmful:
- Avocado — contains persin, toxic to reptiles. Never.
- Rhubarb — high oxalic acid; can cause kidney damage and be fatal.
- Onion and garlic — cause gastrointestinal irritation and toxicity.
- Fireflies / glow bugs — outright deadly; the compounds that make them glow are lethal to dragons.
- Centipedes, venomous insects, and any wild-caught bug — toxicity, bites, pesticides, parasites.
- Bananas (heavily phosphorus-skewed) and citrus (acidic) — limit or skip.
- Processed, salty, sugary, or seasoned human food and dairy — a dragon's gut can't handle it.
Supplements: calcium and vitamin D3 are non-negotiable
Captive diets fall short on calcium, so you supplement — every keeper, always:
- Calcium: dust feeders most feedings. Juveniles and gravid females need it most often (think 4–5 times a week and up); adults a few times a week.
- Vitamin D3: lets the body use calcium. Supply it via a D3-containing calcium powder or, better, via strong UVB lighting. UVB is the cleaner route and matters enormously.
- Multivitamin: a reptile multivitamin about once a week rounds out trace nutrients.
Don't megadose — excess calcium or vitamins causes its own problems. The Merck Veterinary Manual's reptile nutrition overview is a solid non-commercial reference on getting supplementation and the calcium-D3 relationship right.
Gut-loading: the quiet multiplier
One habit doubles the value of whatever insect you feed: gut-loading. For 24–48 hours before offering feeders, feed them well — leafy greens, carrot, squash, a quality commercial gut-load. Whatever's in the insect's gut becomes part of your dragon's meal, so a well-fed feeder delivers real vitamins and moisture, while a starved one delivers an empty shell. It costs nothing extra and meaningfully improves the nutrition reaching your dragon. Pair gut-loading with calcium dusting at the moment of feeding and you've covered both the inside and the outside of every bug.
Hydration
Dragons come from arid country and get much of their water from food, but you still provide it. Keep a clean, shallow water dish (deep enough to drown a baby is too deep). Offer water-rich vegetables. Mist greens or the enclosure lightly, especially during shedding or dry spells, and watch for dehydration signs — sunken eyes, wrinkled skin, lethargy. Some dragons take an occasional shallow lukewarm soak well.
Feeding amounts and a few rules that prevent disasters
- Size matters: never feed an insect longer than the space between the dragon's eyes. Oversized prey is the classic cause of choking and impaction.
- Feed to the clock: offer as much as the dragon eats in a 10–15 minute window, then remove leftovers so live insects don't stress or nibble the dragon overnight.
- Feed in the morning: dragons need warmth and daylight hours to digest, so feed after they've basked.
- Watch body condition: a fat pad at the tail base is fine; a bloated belly or a bony tail is a signal to adjust.
Common feeding mistakes to avoid
A handful of errors account for most diet-related health problems I see:
- Feeding adults like babies. Endless insects past the juvenile stage causes obesity and fatty-liver disease. Flip toward greens.
- Skipping supplements. No calcium dusting and no UVB is the direct road to metabolic bone disease.
- Oversized prey. Anything longer than the gap between the eyes risks choking and impaction.
- Wild-caught insects. Free bugs from the yard can carry pesticides and parasites — not worth it.
- Relying on one feeder. Even a great staple needs variety around it for a complete nutrient profile.
- Too much fruit. Sugar adds up fast; keep it to an occasional small treat.
Adapting the diet for special situations
Healthy dragons follow the standard plan, but some need adjustments:
- Overweight dragons: cut fatty feeders (waxworms, superworms), lean hard on low-calorie greens, and add enrichment activity.
- Underweight or recovering dragons: offer nutrient-dense, easy feeders like hornworms and silkworms plus softened vegetables.
- Metabolic bone disease or calcium deficiency: prioritize calcium-dusted feeders, high-calcium greens like collard and turnip, and — critically — correct the UVB, since lighting is usually the root cause.
- Impaction or dehydration risk: offer water-rich foods, small easily digested prey, and check that temperatures are high enough for proper digestion.
When a dragon has a real health issue, loop in an exotics vet rather than improvising — diet is powerful, but it's not a substitute for diagnosis.
Picky eaters
If a dragon snubs greens, mix them with a favorite insect, offer color (bell pepper, squash), try hand-feeding, or wiggle food with tongs to trigger the hunting response. Keep a consistent schedule, offer the most nutritious food when the dragon is most active, and don't overload on treats — a dragon that learns waxworms are coming will hold out for them.
The short version
Flip the ratio with age (babies = bugs, adults = greens), build protein on a clean staple feeder like discoids, make leafy greens the adult foundation, keep fruit small, dust with calcium and run good UVB, and keep the genuinely toxic foods — avocado, rhubarb, onion, garlic, fireflies — out entirely. Do that and feeding a bearded dragon becomes simple, and the dragon stays healthy for its full 8–12 years. None of it is complicated once you internalize the core ideas — flip the ratio with age, supplement and light correctly, keep the toxic foods out — and the payoff is an animal that avoids almost every diet-driven illness in the book.
Want to compare specific feeders? See hornworms vs. discoid roaches, or browse the full exotic animal care library.