Quick Answer: Salmon is our pick for the healthiest fish to eat overall. It delivers roughly 1,800 mg of omega-3s and 22 grams of protein per 3-ounce cooked serving, while sitting in the FDA's low-mercury Best Choices category. Herring, sardines, Atlantic mackerel, and rainbow trout are nearly as good and usually cost less. If your priority is protein for the fewest calories, cod is the leanest at about 90 calories per serving. The seven fish to skip on mercury grounds are shark, swordfish, king mackerel, bigeye tuna, marlin, orange roughy, and Gulf tilefish.
In This Guide
Disclaimer: This article provides general nutrition information and is not medical advice. Nutrient values are approximate and vary by species, origin, season, and cooking method. If you are pregnant, breastfeeding, feeding young children, or managing a health condition, consult a healthcare provider or registered dietitian for guidance specific to your situation.
What Actually Makes a Fish Healthy
Ask ten people which fish is healthiest and you'll get ten different answers, largely because everyone defines "healthy" a bit differently. Here are three key nutritional factors to consider:
Omega-3 content. This is a big differentiator, and the gap between species is enormous. Cold-water fatty fish like salmon, herring, and sardines carry many times the EPA and DHA of lean white fish. The FDA has authorized a qualified health claim stating that supportive (but not totally conclusive) research shows consumption of EPA and DHA omega-3s may help reduce the risk of coronary heart disease and hypertension.
Protein per calorie. Nearly all fish deliver somewhere between 19 and 23 grams of protein per 3-ounce serving. What changes is the calorie cost. Cod hands you 19 grams for about 90 calories. Atlantic mackerel hands you 21 grams for about 190. Neither is wrong, they're just different tools.
Mercury. Larger, longer-lived predatory fish accumulate more methylmercury. The FDA and EPA sort more than 60 species into three categories: Best Choices, Good Choices, and Choices to Avoid. Nearly every fish worth eating regularly is in the first group.
The ranking below leads with omega-3 density, because that's the nutrient where your choice of fish genuinely changes what you get. Every fish on the list is an FDA Best Choice.
The 10 Healthiest Fish to Eat, Ranked
Omega-3 figures are combined EPA and DHA per 3-ounce cooked serving, from USDA data compiled in the NIH Office of Dietary Supplements omega-3 fact sheet. Calorie and protein figures are rounded from USDA FoodData Central and vary with species, origin, and cooking method.
| # | Fish (3 oz cooked) | Omega-3s (EPA+DHA) | Calories | Protein | FDA Category |
|---|---|---|---|---|---|
| 1 | Salmon, Atlantic (farmed) | 1,830 mg | ~150 | ~22g | Best Choice |
| 2 | Herring, Atlantic | 1,710 mg | ~170 | ~20g | Best Choice |
| 3 | Salmon, Atlantic (wild) | 1,570 mg | ~150 | ~22g | Best Choice |
| 4 | Sardines (canned) | 1,190 mg | ~180 | ~21g | Best Choice |
| 5 | Mackerel, Atlantic | 1,020 mg | ~190 | ~21g | Best Choice |
| 6 | Salmon, pink (canned) | 910 mg | ~120 | ~20g | Best Choice |
| 7 | Trout, rainbow | 840 mg | ~130 | ~22g | Best Choice |
| 8 | Shrimp | 240 mg | ~110 | ~22g | Best Choice |
| 9 | Tuna, light (canned in water) | 190 mg | ~100 | ~22g | Best Choice |
| 10 | Cod | 140 mg | ~90 | ~19g | Best Choice |
1. Salmon
Salmon wins on nearly every axis at once: the highest omega-3 load of any commonly available fish, a solid 22 grams of protein, meaningful vitamin D, and a low enough mercury level to eat two or three times a week. If you're weighing salmon specifically for a calorie-controlled diet, we go deeper in our guide to whether salmon is good for weight loss.
2. Herring
Herring is the most underrated fish you can buy at the grocery store. It nearly matches salmon on omega-3s, costs a fraction as much, and is usually sold smoked, pickled, or tinned, which means zero cooking.
3. Sardines
Sardines punch far above their size. Beyond the 1,190 mg of omega-3s, you're eating the soft edible bones, which is why whole sardines are an excellent source of calcium. (Note: boneless sardine fillets don't contain any meaningful amount of calcium.) Buy them packed in water rather than oil if calories matter, and drain them either way.
4. Atlantic Mackerel
One critical distinction: Atlantic and chub mackerel are FDA Best Choices, while king mackerel is on the avoid list. Atlantic mackerel is rich, oily, and cheap, with over a gram of omega-3s per serving.
5. Canned Pink Salmon
The most practical entry here. Canned pink salmon holds roughly half the omega-3s of a fresh fillet at a quarter of the price and none of the cooking, and it's lower in calories than fresh Atlantic salmon. Additionally, whole canned pink salmon with bones is a great way to boost your calcium intake, and the bones are so soft you won't notice their presence.
6. Rainbow Trout
Trout is the gateway oily fish. It has a mild, almost sweet flavor that reads closer to a white fish than to mackerel, but it still brings 840 mg of omega-3s and 22 grams of protein for only about 130 calories.
7. Shrimp
Shrimp is not an omega-3 play. What it offers, though, is the best protein-per-calorie ratio in the seafood case: 22 grams for roughly 110 calories. A bonus? It cooks in about just a few minutes, even from frozen.
8. Canned Light Tuna
Canned light tuna, made from skipjack, is a Best Choice for mercury. Albacore or "white" tuna is a different product from a larger fish and falls into the Good Choices category, meaning one serving a week.
9. Cod
Cod is the leanest mainstream fish and the reason it ranks last here is purely omega-3s. It's still an excellent choice, especially for people who are trying to lose weight. On protein per calorie it beats everything above it: roughly 19 grams for 90 calories.
10. Tilapia
Tilapia gets more criticism than it earns. Yes, it's low in omega-3s. It's also lean, high in protein, inexpensive, widely available, and an FDA Best Choice for mercury. It's a perfectly good everyday protein source.
If You Want the Leanest Fish Instead
Ranking by omega-3s pushes the fatty fish to the top, but if you're building meals around a calorie target, the ranking inverts.
- Under 100 calories per 3-ounce serving: cod, haddock, flounder, sole, and pollock, all with protein around 19 to 21 grams.
- 100 to 150 calories: shrimp, tilapia, canned light tuna, halibut, and rainbow trout, which throws in real omega-3s as a bonus.
- 150 to 200 calories: salmon, herring, sardines, and Atlantic mackerel, where the extra calories are fat and that fat is the point.
High-protein eating patterns help preserve lean mass during weight loss, and fish delivers that protein at a lower calorie cost than most animal proteins. It's one of dozens of options broken down in our 100 Best Foods for Weight Loss guide.
Which Fish to Limit or Avoid
Seven fish are in the FDA and EPA's Choices to Avoid category: shark, swordfish, king mackerel, bigeye tuna, marlin, orange roughy, and tilefish from the Gulf of Mexico. These are large, long-lived predators, and none of them is a weeknight staple.
A middle tier of Good Choices is fine at about one serving per week: halibut, albacore or white tuna, mahi-mahi, snapper, grouper, and Chilean sea bass among them.
Everything else, including every fish in the ranking above, is a Best Choice at two to three servings per week. If you're pregnant, breastfeeding, or feeding young children, stick to that Best Choices list and vary the species. The EPA's version of the advice chart spells out portion sizes by age.
How to Cook Fish Without Undoing the Benefits
Frozen fish is often flash-frozen right after being caught, which means it's frequently fresher than the "fresh" fish sitting in the display case at your grocery store. It's also cheaper. A bag of frozen cod or tilapia fillets costs a fraction of fresh and cooks from frozen in under 20 minutes. Keep a bag in your freezer and you've always got a protein option ready.
Canned fish is the other underrated shortcut.
For weeknight cooking, simplicity wins. Season a fillet with salt, pepper, and lemon, then bake at 400 degrees for 12 to 15 minutes.
What matters is what you don't do to it. A lean cod fillet becomes something else entirely once it's battered and deep-fried. Baking, grilling, broiling, poaching, and air-frying all leave the nutrition roughly intact. If you want to batch-cook fish for the week without it drying out, our Complete Meal Prep Guide covers the technique. And if raw preparations appeal, ceviche is one of the leanest ways to eat white fish.
Frequently Asked Questions
What is the healthiest fish to eat?
Salmon is the strongest all-around pick. A 3-ounce cooked serving delivers roughly 1,800 mg of EPA and DHA omega-3s along with about 22 grams of protein, and the FDA places it in the Best Choices category for low mercury. Herring, sardines, Atlantic mackerel, and rainbow trout are close behind and often cheaper. If you care most about protein per calorie rather than omega-3s, cod, shrimp, and tilapia are the leanest options.
What is the lowest calorie fish?
Cod is the leanest widely available fish at roughly 90 calories per 3-ounce cooked serving with about 19 grams of protein. Haddock, flounder, sole, and pollock are all in the same 90 to 100 calorie range. Shrimp comes in around 110 calories for 22 grams of protein, making it one of the best protein-per-calorie options in the seafood case.
Which fish has the most omega-3?
Per USDA data compiled by the NIH Office of Dietary Supplements, farmed Atlantic salmon leads at about 1,830 mg of combined EPA and DHA per 3-ounce cooked serving, followed by Atlantic herring at roughly 1,710 mg, wild Atlantic salmon at 1,570 mg, canned sardines at 1,190 mg, and Atlantic mackerel at 1,020 mg. Lean white fish like cod and tilapia contain far less, generally under 150 mg.
Which fish has the most protein?
Most fish contain roughly 19 to 23 grams of protein per 3-ounce cooked serving, so protein alone rarely separates them. Tuna sits at the top end at about 25 grams. What varies more is the calorie cost of that protein: cod gives you around 19 grams for 90 calories, while Atlantic mackerel gives you 21 grams for 190 calories because of its fat content.
Which fish should I avoid?
The FDA and EPA place seven fish in the Choices to Avoid category because of high mercury: shark, swordfish, king mackerel, bigeye tuna, marlin, orange roughy, and tilefish from the Gulf of Mexico. Note that king mackerel is the one to avoid, not Atlantic or chub mackerel, which are Best Choices.
Is farmed or wild salmon healthier?
For omega-3s, farmed usually edges out wild. USDA figures show about 1,830 mg of EPA and DHA per 3-ounce serving for farmed Atlantic salmon versus roughly 1,570 mg for wild, because farmed fish carry more fat. Wild salmon is somewhat lower in calories. Both are FDA Best Choices for mercury, so either is a reasonable pick and the difference is smaller than marketing often suggests.
Is tilapia bad for you?
No. Tilapia has a reputation problem it does not really deserve. It is low in omega-3s at roughly 110 mg per serving, so it will not do much for your omega-3 intake, but it is lean, affordable, high in protein at about 22 grams per 3-ounce serving, and sits in the FDA Best Choices category for low mercury. It is a fine everyday protein, but not an omega-3 source.
The Bottom Line
If you want one answer: eat salmon, sardines, or trout twice a week and you're doing great.
If you want the fuller picture:
- For omega-3s: Choose salmon, herring, sardines, or Atlantic mackerel.
- For protein at the lowest calorie cost: Choose cod, haddock, pollock, or shrimp.
- For cost and convenience: Choose canned sardines, canned pink salmon, or canned light tuna.
- For the best all-around balance: Choose rainbow trout, which is low in mercury, low in calories, and still meaningfully high in omega-3s.
If cooking fish sounds like more effort than you want to invest most nights, that's a reasonable position. Our Weight Loss Meal Plan handles portion control and macros for you with calorie-controlled, protein-forward meals. Or use Build-a-Meal Plan and filter by protein target, calorie range, or dietary restriction to assemble a box around exactly what you'll actually eat.
