How much protein is in 100g tuna?

A typical 100g serving of tuna contains about 25 to 30 grams of protein. Canned light tuna packed in water is usually around the lower end of that range, while some fresh or cooked tuna cuts can land closer to 29 or 30 grams per 100g.

The main reason the number changes is water content. Canned tuna, especially when drained, is more concentrated than a raw piece before cooking. Different tuna species also vary a bit in lean mass and fat content, which shifts the protein amount slightly.

Why the protein number changes by tuna type

Not all tuna is nutritionally identical. Yellowfin, albacore, skipjack, and bluefin can differ in protein and fat content. In general, lean tuna varieties are very protein-forward, while fattier cuts may have slightly fewer grams of protein per 100g because more of the weight comes from fat.

Preparation matters too. Tuna packed in oil will usually have more calories than tuna packed in water, but the protein content is often still similar if you compare equal drained weights. Fresh tuna can also lose water during cooking, which makes 100g of cooked tuna more concentrated than 100g raw.

Is tuna a good protein source for muscle and weight goals?

Yes. Tuna is a strong choice if you want a lot of protein without a large portion size. Protein supports muscle repair, helps you feel full, and can make it easier to hit daily protein targets without adding many carbs or much saturated fat.

For active people, tuna can be a practical post-workout option alongside rice, potatoes, fruit, or vegetables. If you’re training at home, Fitnit can help keep your form clean with AI-powered form analysis and automatic rep counting for common bodyweight and dumbbell exercises, which can make higher-protein meal planning easier to pair with consistent training.

What to watch for when eating tuna regularly

Tuna is nutritious, but it should be balanced with the rest of your diet. One issue is mercury: larger tuna species tend to contain more mercury than smaller ones, so variety matters if you eat tuna often. The FDA and other health authorities recommend choosing lower-mercury seafood more often and limiting higher-mercury fish, especially for pregnant people and young children.

Another practical issue is sodium. Canned tuna can be fairly salty depending on the brand and packing liquid, so check the label if you’re watching blood pressure or total sodium intake. If possible, compare nutrition labels rather than assuming all tuna products are the same.

Tips

• Use drained weight when comparing canned tuna nutrition labels, since the liquid can change the protein-per-100g number a lot.
• Pick tuna packed in water if you want a leaner, lower-calorie option.
• Rotate tuna with other protein foods like eggs, Greek yogurt, beans, chicken, and salmon to avoid relying on one source too often.
• If you eat tuna frequently, vary the species and follow mercury guidance from reputable health agencies.
• Pair tuna with fiber-rich foods such as vegetables, beans, or whole grains to make the meal more filling.