What counts as tuna and chicken here?

For a fair comparison, it helps to use common, plain versions: cooked skinless chicken breast and drained canned tuna in water. Those are the forms most people mean when they search for protein per 100g. Different cuts and preparations can change the numbers a lot.

Chicken breast is a lean poultry staple, usually eaten cooked. Tuna is a fish that’s often sold canned, fresh, or frozen. Canned light tuna is convenient and high in protein, while fresh tuna steaks can be a bit different nutritionally. Added oil, breading, or sauces can quickly change the protein-to-calorie ratio.

Protein per 100g: the real comparison

Typical cooked skinless chicken breast provides about 31g of protein per 100g. Canned light tuna in water, drained, is usually around 25–26g protein per 100g. So chicken generally has slightly more protein by weight, but tuna is still in the same high-protein range.

The calorie picture can differ more than the protein number. Chicken breast is very lean, while tuna can be similarly lean if packed in water. If tuna is packed in oil, calories rise fast. If chicken is dark meat or cooked with skin, fat and calories rise too. For strict macro tracking, the exact product label matters more than the food name.

Pros and cons of each

Chicken pros: usually a touch higher in protein per 100g, widely available, very versatile, and naturally low in mercury. Chicken is a strong default choice for meal prep because it’s easy to portion and pair with vegetables, rice, potatoes, or salads. Chicken cons: it can get dry, and breaded or sauced versions may add lots of calories and sodium.

Tuna pros: high protein, fast to eat, no cooking needed if canned, and often very convenient for busy days. Tuna also provides omega-3 fats, especially in some varieties. Tuna cons: mercury is the main concern, so frequent intake should stay within guidance, especially for pregnant people and young children. Canned tuna can also be higher in sodium depending on the brand.

Which one should you choose for your goal?

For maximum protein per 100g, chicken breast usually wins by a small margin. For muscle gain, both are excellent choices because they deliver a lot of protein with relatively few calories when prepared plainly. If you’re trying to eat more protein without much cooking, tuna is especially convenient.

For fat loss, either can work well, but choose the version with fewer added calories: chicken breast or tuna in water are the best bets. For heart health, tuna can be useful because of omega-3s, but the rest of the diet matters more. For frequent use, chicken is the safer everyday option because it avoids mercury concerns. A practical rule: use chicken as your everyday staple and tuna as an easy backup or rotation food. If you track meals or training, Fitnit can help you stay consistent by logging food photos and keeping workouts honest with automatic rep counting and form analysis.

Tips

• Choose plain cooked chicken breast or tuna in water if your main goal is high protein with low calories.
• Check the label for sodium, oil, and serving size before comparing protein per 100g.
• Rotate tuna with other protein sources instead of eating it every day, especially if you’re pregnant or feeding a young child.
• If you want more omega-3s, include tuna sometimes, but don’t rely on it as your only fish.
• Use grilled, baked, or air-fried chicken and tuna salads with lighter mix-ins to keep the protein-to-calorie ratio high.