Cod and tilapia are close enough nutritionally that preparation can matter more than species. In common cooked-food entries, tilapia is around 26 grams of protein and 125–130 calories per 100 grams, while cooked cod is often around 23 grams of protein and roughly 90–105 calories. Tilapia therefore tends to lead by a few grams of protein for the same weight, while cod is leaner and lower in calories. Neither gap is enormous, and both can provide a substantial protein serving without much fat.
Use the same cooked state for a fair comparison
Fish loses water as it cooks. That concentrates protein and calories per 100 grams, so comparing raw cod with cooked tilapia can manufacture a difference that is partly just water loss. On a like-for-like cooked basis, a 5-ounce serving of tilapia may provide roughly 36–37 grams of protein, while the same weight of cod is closer to 32–33 grams.
Actual values vary with species, fillet composition, and moisture loss. The main point is not that one fish is “high protein” and the other is not. Both are high-protein foods; tilapia simply tends to be a bit more concentrated by cooked weight.
Cod’s calorie advantage comes from being extremely lean
Cooked cod commonly contains around 1 gram of fat or less per 100 grams, while tilapia is still lean but may have roughly 2–3 grams. Since fat supplies 9 calories per gram, that small absolute difference helps explain why cod comes in lower in total energy.
Even so, tilapia at about 125–130 calories for roughly 26 grams of protein is hardly calorie-dense. If you are choosing specifically for the lowest calories, cod has the edge. If you are maximizing protein for a fixed cooked weight, tilapia often edges ahead.
Sodium depends heavily on the product
Fresh cod and salt cod should not be treated as the same food. Traditional salted cod is preserved with a large amount of salt and can remain high in sodium even after soaking, depending on thickness, soak time, water changes, and the starting product. A nutrition value for fresh cod does not describe bacalao-style salted fish.
Plain fresh or frozen tilapia is usually relatively low in sodium, but some frozen seafood is treated with salt-containing solutions or other additives. When sodium is important, the package Nutrition Facts panel is more useful than a generic species comparison.
Breading and frying can overwhelm the species gap
A tablespoon of cooking oil contains roughly 120 calories—more than the typical calorie difference between 100 grams of cod and tilapia. Breaded, fried cod can therefore end up far more energy-dense than simply baked tilapia, and the reverse is true too. Baking, broiling, air-frying with little oil, poaching, and steaming preserve the naturally lean profile.
Mercury is not a major separator in U.S. guidance either. FDA and EPA place both cod and tilapia on the “Best Choices” list for people following mercury-specific fish advice. That leaves taste, price, sourcing, and cooking method as reasonable tie-breakers once you know that cod is a little leaner and tilapia often carries a little more protein per cooked ounce.
Texture can indirectly change the meal too. Cod flakes into large, firm pieces and has a more distinctive flavor, while tilapia is mild and softer. If one fish only feels appealing when heavily breaded or covered in a rich sauce, its small nutritional edge can disappear. The better choice is often the fish you enjoy with a simple preparation and a portion that fits the rest of the plate.
Frozen fillets can be just as useful as fresh when they are plain and stored correctly. Added glazes are mostly water, but seasoned or injected products may change sodium. Read the ingredient list if the numbers matter. Once those product differences are controlled, the species-level conclusion remains modest: cod is leaner; tilapia is a little more protein-dense by cooked weight.
Sources
- USDA FoodData Central — Reference food-composition database.
- U.S. Food and Drug Administration — Advice about Eating Fish — Mercury categories and fish-consumption advice.