The short answer: chicken often has a bit more protein

When you compare common lean portions, cooked chicken breast is usually a little higher in protein than tuna. USDA FoodData Central shows roasted chicken breast at about 31 grams of protein per 100 grams, while canned tuna in water is typically around the mid-20s per 100 grams. That means chicken often edges out tuna by a few grams, but the gap is not huge.

Serving size matters a lot. A typical 3-ounce serving of cooked chicken breast can give you roughly 26 grams of protein, while a similar serving of canned tuna commonly provides around 20 to 22 grams. If you’re just trying to hit a daily protein target, either one works very well.

Why the comparison changes depending on the type

Not all tuna and chicken are created equal. Chicken breast is one of the leanest cuts of poultry, but chicken thigh, breaded chicken, or fried chicken will have less protein per calorie and more fat. Tuna also varies: albacore, skipjack, and canned varieties differ slightly in protein and calories.

Preparation matters too. Water-packed tuna usually has more protein density than tuna packed in oil because the oil adds calories without adding protein. For chicken, grilled, baked, or roasted preparations keep the protein-to-calorie ratio high, while breading and frying dilute that advantage.

Protein is not the only thing to compare

If your goal is muscle gain or fat loss, protein is important, but total calories, fat, and sodium matter too. Chicken breast is very lean and versatile, which makes it easy to build meals around. Tuna is also lean, but canned tuna can be higher in sodium depending on the brand and packing liquid.

There’s also a food-safety angle with tuna. Larger tuna species can contain more mercury, so people who eat a lot of tuna should pay attention to guidance from the FDA and EPA, especially pregnant people and young children. Chicken does not have that mercury issue.

Which is better for your goal?

Choose chicken if you want the highest protein per serving in a familiar, easy-to-build meal, especially when you’re using chicken breast. It’s a strong choice for meal prep and for people who want a lean protein with minimal mercury concerns.

Choose tuna if you want a convenient, shelf-stable protein source that is still very high in protein and often lower in calories. It’s especially useful when you need a fast meal, but keep an eye on sodium and rotate it with other protein sources.

Tips

• For a true apples-to-apples comparison, compare cooked chicken breast to tuna packed in water and drained.
• Check the nutrition label because canned tuna can vary a lot in sodium and calories.
• If you eat tuna often, rotate in other proteins to reduce mercury exposure.
• For muscle-building meals, aim for a lean protein plus carbs and vegetables instead of protein alone.
• Use a food photo tracker or macro tool to see whether your real portions match your protein goal.