🐡 Canned tuna in water (drained) provides 109 kcal and 25g protein per 100g — one of the highest protein-to-calorie ratios of any common food.
Source: USDA FoodData Central · Canned In Water, Drained · Data verified by CaloriesCalc
* % Daily Value based on a 2,000 kcal diet.
| Nutrient | Amount | % Daily Value | Bar |
|---|---|---|---|
| Niacin (B3) | 18.8mg | 117% | |
| Vitamin B12 | 2.21µg | 92% | |
| Selenium | 56.3µg | 102% | |
| Vitamin B6 | 1.04mg | 61% | |
| Potassium | 441mg | 9% | |
| Phosphorus | 311mg | 25% | |
| Magnesium | 35mg | 8% | |
| Vitamin D | 5.7µg | 57% | |
| Iron | 1.0mg | 6% | |
| Zinc | 0.77mg | 7% |
| Weight | Calories | Protein | Fat | Carbs |
|---|
Canned tuna in water: ~109 kcal/100g. Canned in oil: ~200 kcal/100g. Fresh/cooked yellowfin: ~144 kcal/100g. Albacore (white tuna) has more omega-3 but also more mercury than skipjack (light tuna).
Fresh tuna provides 29.9g of protein per 100g at only 144 kcal — a protein-to-calorie ratio of 0.83, rivalling turkey breast (0.89). A can of tuna in water delivers 42g of complete protein at under 200 calories. Tuna protein has a PDCAAS of 1.0 — the maximum score, indicating perfect amino acid balance relative to human requirements.
Tuna provides 56.3µg of selenium per 100g — 102% of the daily value. A single 100g serving completely covers the daily selenium requirement. Selenium is essential for the antioxidant enzyme glutathione peroxidase, thyroid hormone metabolism, and DNA synthesis. Selenium in fish (selenoneine — a unique selenium compound found only in marine animals) has higher bioavailability than selenium in plant foods or supplements.
Tuna provides 1.04mg of vitamin B6 per 100g — 61% of the daily value. B6 is essential for over 100 enzyme reactions, including serotonin, dopamine, and GABA synthesis. High B6 intake is associated with reduced risk of depression, improved cognitive function, and lower homocysteine levels (a cardiovascular risk factor). Tuna is one of the richest dietary sources of B6.
Tuna is one of the most concentrated food sources of niacin (B3), providing 18.8mg per 100g — 117% of the daily value. Niacin is essential for over 400 NAD-dependent reactions, including energy production, DNA repair, and cell signalling. Pharmacological doses of niacin are used clinically to raise HDL cholesterol — tuna's niacin content, while not pharmacological, contributes meaningfully to daily intake.
Nutrition values from USDA FoodData Central. Not medical advice.