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Protein data

Protein in Tuna

One 1 can tuna in water of tuna contains 42g of protein at 191 kcal. That\'s a protein-per-calorie ratio of 22.0g per 100 kcal — one of the highest protein-per-calorie ratios available — ideal for muscle preservation and satiety during cuts.

Protein density
22.0g/100kcal
EXCELLENT
Per primary serving
42g
1 can tuna in water

Protein by portion size

Portion Protein (g) Calories g protein / 100 kcal
1 can tuna in water (165g drained) 42 191 22.0
100g canned tuna in water 26 116 22.4
100g canned tuna in oil 29 200 14.5
100g fresh yellowfin tuna (cooked) 28 130 21.5
100g fresh bluefin tuna (cooked) 30 184 16.3

How much tuna to hit your protein target?

Phillips & Van Loon 2009 (JISSN) established 0.4 g/kg per meal as the per-meal threshold to fully stimulate muscle protein synthesis — roughly 25–40g for most adults. To hit those targets purely from tuna:

What this protein density means

For perspective, the highest-density protein whole foods cluster around 15–19g of protein per 100 kcal: chicken breast 18.8, white fish 16–17, Greek yoghurt 17 (non-fat), tuna 15. Medium-density sources (5–12 g/100kcal) include eggs, beef, salmon, tofu, and lentils. Below 4g/100kcal, foods are primarily carb or fat sources with incidental protein. Tuna at 22.0g/100kcal is firmly in the high-density tier — fits naturally as a primary protein source in any high-protein eating plan.

Protein density comparison

Reference points for context (g protein per 100 kcal):

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Protein content of related foods

Frequently asked questions

How much protein is in tuna?
Tuna contains approximately 42g of protein per 1 can tuna in water (191 kcal). Per 100g, that's 25.5g of protein. The protein-per-calorie density is 22.0g per 100 kcal — classified as excellent.
Is tuna a good source of protein?
Yes — tuna is a strong protein source. One of the highest protein-per-calorie ratios available — ideal for muscle preservation and satiety during cuts. For comparison: chicken breast delivers 18.8g protein per 100 kcal; Greek yoghurt 17g; eggs 8g; lentils 8g; rice 2g.
How much protein do I actually need per day?
The Morton 2018 meta-analysis in the British Journal of Sports Medicine (49 randomised trials, 1,863 subjects) established 1.62 g/kg of body weight per day as the dose-response plateau for muscle gain from resistance training. For active adults during fat loss, the Helms 2014 review recommended 1.8–2.2 g/kg of total body weight to preserve lean mass. The old RDA of 0.8 g/kg is a population minimum, not an optimum. For a 70 kg adult, evidence-based daily protein targets are 112–154g.
How is protein quality measured beyond grams?
The Digestible Indispensable Amino Acid Score (DIAAS) is the modern protein quality measure, evaluating both amino acid profile and digestibility against human requirements. Animal proteins — whey, casein, eggs, chicken, fish — score 1.0+ (complete and highly digestible). Most plant proteins score below 1.0: pea ~0.82, rice ~0.59, soy ~1.0 (the plant exception). For vegans, combining sources across the day (legumes + grains, soy + nuts) produces a complete amino acid profile and offsets the digestibility gap by targeting the upper end of intake ranges.
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