When it comes to choosing the healthiest fish to eat, there are certain species that will give you more nutritional bang for your buck. How the fish is prepared will also impact how healthy it is for you to eat. Some types put you at higher risk for contamination, while some have more allergenic potential. And some fish are just a lot more expensive. Let’s reel in the facts and answer the question: "What is the healthiest fish to eat?" Our overarching conclusion: most fish are healthy, so get your recommended two servings/week so you don’t miss out on this easy and delicious addition to a healthy diet. 

If you're looking for an easy way to compare calorie and macro information, and get insights into your blood sugar response to fish and any other food or drink, consider using the January app. It's completely free to download and use and allows you to look up and compare different foods so you can make the healthiest choice possible.

Download the free January app here to look up your favorite fish.

What makes fish healthy?

Fish provides an optimal source of complete animal protein, a low amount of saturated fat, plentiful heart-healthy omega-3 fatty acids, and a wide range of vitamins and minerals.

• Protein: Fish is one of the healthiest protein-containing foods you will find. As explained in What is Protein? An Essential Guide, the best protein sources are those that are nutrient-dense, providing a wide range of nutrients that impact your health. Foods with protein are slower to digest, help keep your blood sugar steady, and provide more sustained energy than those foods containing primarily carbohydrates. Fish is a complete protein with all the essential amino acids. Fish also has less connective tissue than red meats or chicken , making it easier on the digestive system.

• Fat: Oily fish are a rich source of omega-3 fatty acids, polyunsaturated fats found in cell membranes that help cells communicate with each other and are precursors to anti-inflammatory pathways. Since inflammation is believed to play a central role in the development of many chronic disease states, omega-3s (and their role in quelling inflammation) are considered beneficial for gut, heart, and brain health. Fat also adds flavor and, like protein, provides a sustained source of energy and contributes to satiety.

• Vitamins and minerals: Like other animal proteins, fish is a good source of iron and vitamin B12, both needed for the health of red blood cells. Fattier species of fish also pack a punch of the fat-soluble vitamins A and D, important for many functions including vision and immune health. The minerals iodine, zinc, and selenium are important for thyroid and immune health and the latter may also counter adverse effects of mercury found in some fish species. Canned fish, which contains bones that are softened during the canning process, is a good source of calcium. Most fish also contain moderate to small amounts of choline, potassium, and magnesium; plus copper, phosphorus, and other trace minerals. 

What are the health benefits of fish?

According to a 2022 review, the health benefits of fish consumption can be attributed to antioxidant and anti-inflammatory activity, neurological and liver protective properties, and wound healing attributes. 

Much of the research has focused on the omega-3 content of fish, which contributes to decreasing risk for cardiovascular disease (CVD). However, a review of the research also links regular fish consumption to reduced impact on metabolic and hormone related conditions — including metabolic syndrome, obesity, diabetes, hypothyroidism, polycystic ovary syndrome, and the menopausal transition. Additionally, although results are not conclusive, a wide body of research suggests that omega-3 fatty acids from fish may enrich infant neurodevelopment, provide cognitive support for degenerative disease, and support mental health.

How often should I eat fish?

Dietary federal guidelines and the American Heart Association recommend consuming two servings of fish per week (~8 oz.) as part of a healthy eating pattern. One 4 oz. serving is about the size of a deck of playing cards. The recommendations for fish consumption vary depending on life stage:

• Pregnant and breast-feeding women: 2-3 servings (8-12 oz.) per week
• Children: once per week in smaller portions (~2 oz.) according to age and total calorie needs
• Adults: 2 servings per week (8-12 oz.)

It is estimated that only 10-20% of Americans meet the federal recommendations for weekly consumption of seafood. 

What is the healthiest way to cook fish? 

Those who did not grow up eating fish regularly or who live in an area where fish is not readily available might be intimidated when it comes to cooking fish, but there are many simple and delicious ways to prepare seafood. A tried, true, and one of the healthiest ways to cook fish is to drizzle it with olive oil, squeeze a little lemon on top, sprinkle with your favorite seasoning, and broil until it turns opaque and flaky. Seafood Nutrition Partnership, a non-profit that raises awareness about the nutritional benefits of seafood, offers a slew of fish recipes that can be searched by dietary considerations, cooking method, and seafood type. Another source: these simple and healthy chef- and nutritionist-vetted recipes.

Is fried fish healthy?

Fried fish contains carbs from the breading and fat from the oil, both contributing to overall calorie count. Worse, the frying process can decrease the level of omega-3 fatty acids. (Note: It is important to consider the type of oil used, as explained in What Is the Healthiest Cooking Oil To Use?) A review of research on fish consumption and cardiovascular health suggests that when comparing consumption of non-fried fish to fried fish, the latter is associated with an increased risk of overall cardiovascular disease events. Therefore, it’s best to aim for preparing or ordering broiled, baked, or poached fish most of the time

Should I be worried about the mercury content in fish? 

While it should be quite clear by now that regular fish consumption should be part of a healthy diet, certain species of fish have elevated levels of heavy metals, such as mercury and industrial chemicals (including polychlorinated biphenyls, or PCBs). These contaminants can cause damage to the nervous system in adults and disrupt development of both a fetus and of a young child, which is why there are specific intake recommendations for both pregnant women and children. The amount of mercury accumulation in fish has largely to do with where they fall on the food chain; larger and bottom-feeding fish typically contain higher levels of contaminants. The Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA) have issued advice on fish consumption that includes a list of fish grouped by the best, good, and those with the highest mercury levels.  The list of high-mercury fish to avoid includes:

• King mackerel
• Marlin
• Orange roughy
• Shark
• Swordfish
• Tilefish (from the Gulf of Mexico)
• Tuna (Bigeye)

Healthy adults who are not pregnant or nursing can safely consume the species listed above as an occasional healthy source of protein. Although the mercury content in fish may be a concern for certain consumers, the weight of scientific evidence clearly demonstrates that the benefits of consuming fish far outweigh the low risk of mercury contamination. 

Are sustainable fish healthier?

In addition to considering what makes a fish healthy for human consumption, many consumers are cognizant of how the choice to consume fish might impact the health of the environment. Sustainable choices are those which are farmed or are fished in such a way as to minimize harm to the environment, don’t threaten or endanger reproduction of a species, and come from an operation that assures human rights and good labor conditions for their employees. Monterey Bay Aquarium's Seafood Watch is a great resource for identifying species that are considered sustainable choices. 

Sustainability does not necessarily equate to healthy, however. Both the nutritional quality of fish and whether it contains contaminants can be impacted by where it comes from and what it eats. Wild fish  eat a natural diet and tend to be slightly lower in saturated fat than farmed fish, whereas farmed fish may be slightly higher in omega-3s due to fortification of feed. Many fish retailers have sustainability information readily available to help consumers identify and select sustainable fish options. 

What is the healthiest fish to eat?

There are a wide variety of nutritional attributes in fish. Here is a list of five of the healthiest fish you might consider to get the most nutritional bang for your buck from your two servings per week:

1. Salmon

Salmon might just qualify as the poster child among healthy fish — and for good reasons! Salmon is an excellent source of protein and it is more oily than other fish species, contributing to its high content of omega-3s. Salmon is delicious simply grilled or broiled with garlic, a dollop of butter, and a squeeze of lemon. A 4 oz. filet of wild-caught Atlantic salmon contains: 

• ~230 calories; 28 grams of protein; 9 grams of total fat; 2,500 mg of omega-3s; 1.2 mg of iron; 3.45 µg of B12; 500 IU of vitamin D

2. Sardines, anchovies, herring

Sardines, anchovies, and herring are smaller species of fish which, when compared to larger species,  makes them less likely to accumulate mercury and other contaminants. Although available fresh in some regions, these species of fish are typically canned, making them readily available anywhere. Some consumers may find canned fish too “fishy,” but from a nutrition perspective, they get a high rating — as they are loaded with calcium (if you choose to eat the bones) and vitamin B12. Just be aware that canned fish can be high in sodium, so limit your portion size and how often you consume canned fish, especially if sodium is of particular concern to you. For a flavorful, nutritious boost, try adding sardines, anchovies, or herring to pasta dishes, mash them on toast, or blend into egg salad or salad dressing. For further nutrition details and recipes using canned sardines, checkout this article: Are Sardines Good for You? A 2 oz. serving of sardines canned in oil with bones contains: 

• ~118 calories; 14 grams of protein; 6.5 grams of total fat; 556 mg of omega-3s; 1.6 mg of iron; 5.06 µg of B12; 110 IU of Vitamin D

3. Tuna

Hands down, tuna is one of the most popular types of fish to eat. Budget-friendly canned tuna in water or oil is readily available in supermarkets, and fresh or frozen tuna filets are also fairly easy to find. Most tuna species are on the larger side, so it is important to consider where it comes from and how often you consume it so as not to overdo the potential for mercury. Chunks of canned tuna or a nice filet of grilled tuna is a fabulous, protein-rich addition to any salad. A 4 oz. filet of skipjack tuna contains: 

• ~150 calories; 32 grams of protein; 1.5 grams of total fat; 389 mg of omega-3s; 1.8 mg of iron; 2.5 µg of B12;50-250 IU of Vitamin D (varies with type of tuna)

4. Cod

Cod is easy to find in the frozen section of most stores; just be cautious of the pre-seasoned, pre-battered versions that can pack on extra calories and sodium. If you can find fresh cod, it is a delicious and mildly flavored fish that is adaptable to many recipes and readily enjoyed by the whole family. A 4 oz. filet of cooked cod contains:

• ~134 calories; 21 grams of protein; 4.8 grams of total fat; 184 mg of omega-3s; .25 mg of iron; 2.5 µg of B12; 60 IU of Vitamin D 

5. Mackerel

Another excellent source of omega-3s and B12, mackerel is a healthy, affordable, and sustainable fish with low levels of mercury. It is oilier than tuna and less fishy than sardines. Baking, grilling, and pan-frying are popular preparation methods for mackerel. A 4 oz. serving of mackerel contains:

• ~297 calories; 27 grams of protein; 20 grams of total fat; 1,480 mg of omega-3s; 1.8 mg of iron; 21 µg of B12; 100 IU of Vitamin D 

What is the healthiest white fish to eat?

Species of white fish — such as cod, flounder, tilapia, and sole — are very lean and lower in total fat and omega-3s than fish like salmon and mackerel, but they still contain a good amount of healthy protein, vitamins, and minerals. 

What is the healthiest fish for weight loss?

Just like there is no magic pill for weight loss, there is no magical fish that you can consume to help you lose weight. However, it is interesting to note that some research has linked omega-3 intake (and the concurrent decrease in inflammation) to weight loss. One study in particular suggests that intake of omega-3s can help reduce risk of chronic diseases associated with obesity due to inhibition of inflammatory mechanisms. Upon further analysis, it appears that while omega-3s may not directly aid weight loss, they may attenuate further weight gain and thus could be useful to help maintain weight loss. Lastly, circulating levels of omega-3 are positively correlated with adiponectin, a hormone which controls fat cell activity. Fatty fish (e.g., mackerel and salmon) are highest in omega-3s, so either of those two species could be top choices for weight loss.

Does fish raise blood sugar?

Because fish is high in protein and low in carbs it will be easy on your blood sugar. The easiest way to tell for sure is by using the free January app to look up your predicted glucose response to any type of fish and gauge your spike. As you see in the screenshot from the app below, fish won't raise your blood sugar.

Should shellfish high in cholesterol be avoided?

Although rich in protein and low in mercury, shellfish (crab, shrimp, lobster) are higher in cholesterol than other fish species. But that doesn’t mean you have to avoid these delicious and otherwise nutritious crustaceans. It is recommended that cholesterol intake be kept at less than 300 mg per day, and shellfish typically contain around 100 mg per 4 oz. serving. Squid (calamari) has the highest cholesterol level of any seafood, at nearly 300 mg per 3 oz. serving. As discussed in the article, How to lower cholesterol, some research has suggested that the intake of omega-3-rich fatty fish impacts (negatively) triglyceride and cholesterol levels. However, you don’t have to avoid shellfish for this reason;  just eat it less often. (Additional note: allergies to shellfish are the most common food allergy in adults, and among the most common in children.)

What are some ways I can add more fish to my diet?

If you’ve fallen hook, line, and sinker for the healthful benefits of adding more fish to your diet, but you are struggling with preparation and how to get your two servings per week consistently, consider these ideas: 

• Make a fish burger or sandwich. You don’t have to limit yourself to broiled, baked, or pan-fried fish. Many stores have frozen or fresh salmon patties, or you can make your own patty to create a tasty fish burger. Fresh tuna steaks also are an easy and delicious addition to your favorite sandwich roll; simply season, grill, add some tomato, lettuce, or other condiments.
  

• Top your salad with a grilled fish filet. A lightly seasoned, grilled halibut filet is a fabulous topper for any salad. This is a win-win option for revving up your vegetable and protein intake for lunch or dinner.
  

• Fish tacos anyone? Spice up your taco Tuesday by swapping fish or shrimp for your usual meat or chicken protein taco filler.
  

• Order fish at restaurants. Considering that most Americans eat out at least once per week, if you make it a point to order fish when you go out, you are halfway to your goal of two-servings per week.
  

• Worried about fish not fitting into your budget? Canned and frozen options for fish are available in a wide range of price points. Canned clams or frozen shrimp can easily be incorporated into a scrumptious pasta dish. There is always the budget-friendly option of canned tuna to add to a salad, or a simple tuna fish sandwich.
  

• What if I don’t like fish? If you think you don’t like fish, think again and start trying some of the many varieties you may not have sampled. Both cod and tilapia are good fish to start with, as neither has a strong fishy taste and they both take on the flavor of the sauce or marinade you use as you prepare or eat them.

Tips for choosing the healthiest fish

• If possible, buy fish from a market that gets fresh shipments daily.
• Select fish that smells mild, is not discolored or dry around the edges, and has firm flesh that springs back when touched.
• If buying a whole fish, look for clear, shiny eyes.
• Vary the different types of fish you select (i.e., salmon vs. cod; small fish vs. big fish)

Key takeaways

Fish provides an excellent source of protein, healthy fats (that are particularly rich in heart-healthy omega-3s), and an array of essential vitamins and minerals — all of which contribute to the many health benefits of consuming fish. There are a wide variety of fish species and endless creative options for how to prepare them. Be conscious of where your fish comes from, and whether you choose fresh, frozen, or canned. Make it your goal to add at least two servings of fish to your weekly meal plan. Chances are, you’ll live longer if you do.