How much protein is in 100 grams of tuna?

A typical 100-gram serving of tuna supplies about 23 to 29 grams of protein. Leaner tuna preparations tend to land toward the upper end of that range, while tuna packed with added oil or different species may shift the numbers slightly.

For context, 100 grams is roughly 3.5 ounces. That amount is a solid single serving for a meal and can easily support a high-protein lunch or dinner. USDA FoodData Central is the best reference for the exact number because values vary by product and preparation method.

Why the number changes by tuna type

The protein content changes because tuna products aren’t identical. Fresh tuna steak, canned light tuna, canned albacore, and tuna in water versus oil can all have different nutrition profiles. Water-packed tuna usually has fewer calories than oil-packed tuna, but the protein is often similar enough that the bigger difference is in fat and total calories.

If you are tracking macros closely, check the label or USDA database entry for the exact product you buy. That is especially important if you use tuna as a routine protein source for meal prep, sports nutrition, or weight management.

How 100 grams of tuna fits into a high-protein diet

A 100-gram tuna portion is useful because it delivers a lot of protein in a relatively small amount of food. Protein supports muscle repair, satiety, and maintenance of lean mass, especially when paired with resistance training.

For people training at home, keeping protein intake consistent can matter as much as the workout itself. Fitnit can help with that training side by counting reps automatically and analyzing form from your phone camera, which may help you keep technique consistent while you build strength.

Other nutrition points to know before eating tuna often

Tuna is also notable for sodium content in canned versions and for mercury concerns, especially with larger tuna species. The FDA and EPA advise limiting high-mercury fish for certain groups, including pregnant people and young children. If tuna is a frequent staple, rotating in other protein sources like salmon, sardines, eggs, Greek yogurt, beans, or chicken can help balance your diet.

The takeaway: tuna is an efficient protein choice, but it works best as part of a varied diet rather than your only protein source.

Tips

• Use a kitchen scale if you want an accurate 100-gram serving.
• Check the label to see whether your tuna is packed in water or oil.
• Rotate tuna with other protein foods to reduce mercury exposure over time.
• Pair tuna with fiber-rich foods like vegetables, beans, or whole grains for a more balanced meal.
• If you’re building muscle, spread protein across the day instead of putting it all in one meal.