The healthiest fish depends on your needs: for omega-3, sardines and mackerel; for protein with minimal fat, cod and hake; for vitamin D, salmon and herring; for low mercury, sardines and anchovies. In this ranking, we analyze the 15 healthiest fish by nutrients, with a comparative table and recommendations by objective.
Ranking criteria: what makes a fish healthy
There isn't one universal "healthiest fish." It depends on the criteria. For this ranking, we evaluated 5 factors:
- Protein per 100g — quality and quantity of amino acids
- Omega-3 (EPA+DHA) — fatty acids the body cannot produce
- Mercury — less is better (heavily penalized in the ranking)
- Vitamins and minerals — vitamin D, B12, selenium, iodine
- Calorie/nutrient ratio — nutritional density per calorie
Each fish receives an overall score out of 10 based on these 5 factors.
Top 15 healthiest fish
1. Sardine (9.2/10) — The absolute champion. High in omega-3 (1,480 mg/100g), very low in mercury, rich in calcium (if eaten with bones) and vitamin D. Cheap and sustainable.
2. Wild Salmon (9.0/10) — The king of omega-3 (2,150 mg) and vitamin D (526 IU/100g). Low in mercury. Wild salmon surpasses farmed salmon in fatty acid profile.
3. Atlantic Mackerel (8.8/10) — More omega-3 than salmon (2,670 mg) but slightly more mercury. Economical and underestimated.
4. Cod (8.5/10) — Highest in protein per calorie (82% of calories = protein). Very low in fat and mercury. Ideal for diets and as a protein base.
5. Anchovy (8.4/10) — Similar to sardine: high omega-3, very low mercury, rich in calcium. Anchovies in oil further concentrate nutrients.
6. Trout (8.2/10) — Good balance of omega-3, protein, and low mercury. Very accessible and versatile in cooking.
7. Herring (8.0/10) — Very high in vitamin D (1,628 IU/100g), omega-3, and vitamin B12. Not widely consumed in Spain but nutritionally excellent.
8. Hake (7.8/10) — The most popular white fish in Spain. Low in fat, high in protein, low in mercury. Ideal for diets.
9. Sole (7.6/10) — Very low in fat and calories (86 kcal/100g). High-quality protein and perfect for babies and sensitive digestive systems.
10. Mussels (7.5/10) — Richest in iron (6.7 mg/100g) and vitamin B12 of all shellfish. Very high in selenium and zinc. Inexpensive.
11. Sea Bream (7.3/10) — Good protein profile, low in fat. Slightly more mercury than the previous ones but within safe levels.
12. Sea Bass (7.2/10) — Similar to sea bream. Good protein, moderate fat. Very versatile in cooking.
13. Prawns (7.0/10) — Very high in protein (24 g/100g) and very low in calories (99 kcal). Low in mercury. Contains cholesterol but does not significantly affect blood cholesterol.
14. Octopus (6.8/10) — High in protein, low in fat and calories. Rich in vitamin B12 and minerals. Somewhat low in omega-3 compared to fatty fish.
15. Farmed Salmon (6.5/10) — Good omega-3 but higher omega-6 content than wild. More total fat. Nutritionally sound but inferior to wild salmon.
Comparative table of nutrients per 100g
| Fish | kcal | Protein | Fat | Omega-3 | Score |
|---|---|---|---|---|---|
| Sardine | 208 | 25 g | 11 g | 1.480 mg | 9.2 |
| Wild Salmon | 182 | 25 g | 8 g | 2.150 mg | 9.0 |
| Cod | 82 | 18 g | 0.7 g | 240 mg | 8.5 |
| Mackerel | 262 | 24 g | 18 g | 2.670 mg | 8.8 |
| Hake | 90 | 18 g | 1.3 g | 320 mg | 7.8 |
| Mussels | 172 | 24 g | 4.5 g | 780 mg | 7.5 |
Best fish for protein
If you're looking to maximize protein with minimal calories, white fish win: cod (82% of calories = protein), hake, sole, and prawns. Cod is probably the most efficient protein source in nature: 18g of protein in just 82 kcal.
Best fish for omega-3
Oily fish dominate: mackerel (2,670 mg), wild salmon (2,150 mg), herring (1,730 mg), and sardines (1,480 mg). Cod, despite being excellent in protein, has little omega-3 (240 mg) — it's white fish. For omega-3, you need fat. Read our complete omega-3 fish ranking.
Best fish for diet and weight loss
Cod and hake are the best allies for weight loss: very low in calories (82-90 kcal/100g), very high in protein (which satiates and preserves muscle mass), and practically fat-free. 200g of steamed cod = 164 kcal and 36g of protein. It's hard to find anything better.
Salmon also works well for diets despite having more calories: its high omega-3 content improves insulin sensitivity and reduces inflammation, two factors that facilitate fat loss.
Best fish for pregnancy
Combination of DHA omega-3 (crucial for fetal brain development) + low mercury: salmon, sardines, cod, and trout. Read more in our guide on mercury in fish and fish for babies.
Oily vs white fish: which is healthier?
Neither is better or worse — they are complementary:
Oily fish (sardine, salmon, mackerel): more fat, more omega-3, more calories, more vitamin D. Ideal for cardiovascular and brain health.
White fish (cod, hake, sole): less fat, more protein per calorie, low in calories. Ideal for diets and as an efficient protein source.
The optimal nutritional recommendation is to alternate both: 2 servings of oily + 2 of white per week.
Is canned fish just as healthy?
Yes, with nuances. Canned fish retains the vast majority of nutrients:
- Omega-3: 70-80% preserved.
- Protein: intact.
- Calcium: canned sardines with soft bones have more calcium than fresh ones.
- Sodium: higher in canned goods (due to salt in brine). Choose "low-salt" options.
Conclusion
There isn't one universal "healthiest fish" — there are ideal fish for each objective. If we had to choose one: the sardine, for its unbeatable combination of omega-3, low mercury, price, and sustainability. For pure protein, cod is unrivaled. For maximum omega-3, mackerel or wild salmon.
What's important isn't which is best, but eating fish 3-4 times a week, alternating between white and oily. Any fish on this list is infinitely better than not eating fish.
Frequently asked questions
What is the healthiest fish in the world?
Sardines rank first for their combination of omega-3, low mercury, calcium, vitamin D, and accessible price. Wild salmon is an excellent alternative.
Is cod a healthy fish?
Very healthy. It's the most efficient protein source from the sea: 18g of protein in just 82 kcal. Low in fat, low in mercury, and high in selenium. Ideal for diets.
Which is healthier, oily fish or white fish?
They are complementary. Oily fish has more omega-3 and vitamin D. White fish has more protein per calorie and less fat. The ideal is to alternate both.
Is wild salmon better than farmed salmon?
Wild salmon has a better fatty acid profile (more omega-3, less omega-6). Farmed salmon is nutritionally sound but inferior to wild.
Is canned fish as healthy as fresh?
Yes, it retains intact protein and 70-80% of omega-3. Canned sardines with bones even have more calcium than fresh ones.
How many times a week should I eat fish?
3-4 times a week according to the WHO and AEP, alternating 2 servings of oily and 2 of white fish.
What is the best fish for weight loss?
Cod and hake: 82-90 kcal per 100g with 18g of protein. Highly satiating and practically fat-free.
Lalo González Rodríguez
Since 1990 at Mercat del Ninot, Barcelona. We select cod and seafood products directly from the producer. It's not marketing — there are verifiable factors.
