Fish to Eat for Health: Dietitian Advice

Fish is an essential part of a healthy diet. Experts recommend two servings of four ounces or one serving of 8 ounces of fish per week. UnityPoint Health dietitian Miriam Troutner explains the health benefits of eating fish, the importance of omega-3 fats and some recipe ideas to keep your dinner plans fresh.

Health Benefits of Fish

Eating fish is associated with several health benefits, including lowering triglycerides (type of fat), blood pressure and inflammation, improving eye health, reducing the risk of heart disease and stroke, protecting brain health and reducing Alzheimer’s progression. Fish are rich in minerals such as calcium, zinc and magnesium, and it’s a key source of omega-3 fatty acids.

What are Fatty Fish?

Omega-3s are called essential fatty acids because they're necessary for health, but your body can’t make the good fat on its own — you must ingest it. Although omega-3 fats can be found in some grains, plant-based oils and certain algae and seaweed, the best source is fish. 

Fish has more omega-3s per serving, and it’s in a form our bodies absorb best called EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). The omega-3 fats found in grains and plant fats are called ALA (alpha-linolenic acid). Your body can convert ALA to EPA/DHA, but you’ll benefit most by getting EPA straight from fish. 

• Fatty fish: Salmon, sardines, tuna, herring and trout are fish particularly high in omega-3s.
• Lean fish: Haddock, pollock, catfish, flounder and halibut are leaner fish containing less omega-3 fats.

While it’s best to eat fish for healthy omega-3 fats, make sure to get other healthy ALA fats from foods such as ground flaxseed, avocados, walnuts and olive oil. For individuals who choose not to or cannot consume fish due to allergies, getting a good amount of ALA fats is important.

How to Choose a Healthy Fish to Eat

You might think certain fish may have too strong of a flavor or are difficult to cook. Troutner recommends trying different species to find something you like. If you’re able, buy fish that’s responsibly sourced, which you can learn about from NOAA (National Oceanic and Atmospheric Administration) or from seafoodwatch.org.

Is Flounder Healthy? 

Flounder is a healthy saltwater fish. It’s a mild, white fish with a similar texture to tilapia and high in vitamin B12. Unlike tilapia, flounder has omega-3 fats. Next time you’re making a recipe that calls for tilapia, try swapping in flounder instead. 

On the other hand, if you’re trying to pick from flounder vs. salmon, consider the source of the fish. According to the NOAA, “summer flounder” from the United States is sustainably managed and responsibly harvested under U.S. regulations. Flounder is a leaner fish, which means it’ll have fewer calories but also less omega-3s than salmon.

Is Salmon Healthy? 

Salmon is often a top protein pick by dietitians and other health experts. It’s low in saturated fat and high in omega-3s. It’s also a good source of vitamin B12, potassium and vitamin D. Salmon is versatile and easy to prepare. The higher fat content (compared to flounder) makes it a more satisfying and filling meal.

Is Haddock Healthy? 

Like flounder, haddock is a very lean fish with less than 1 gram of fat per fillet, so choosing this fish can be a great way to add more protein without additional calories. The saltwater fish is considered to have stronger flavors and more texture than its closest relative — cod. Unlike cod, haddock contains good amounts of omega-3 fats.

What’s the Leanest Fish to Eat? 

Most fish are generally considered a lean source of protein. This technically means it contains less than 3 grams of fat per ounce or less than 10 grams of fat in 100 grams portion. Beware, because fish is such a lean source of protein, many recipes add additional fat in cooking or serving to enhance the flavor. Save fried fish for special occasions and limit creamy sauces if you eat fish routinely.

What’s the Best Fish for Weight Loss? 

There’s no right or wrong fish to select for weight loss, specifically. Even fish that contain good amounts of omega-3 fats are still lower in calories compared to other proteins but provide the additional benefit of the essential omega-3 fats. 

Is Fried Fish Healthy for You?

The preparation is what can derail your weight loss efforts. Avoid fried fish or fish topped or served with mayo/sour cream sauces. 

Fried fish is less healthy, because the frying process adds significant calories and fat from the oil it absorbs. Additionally, high-temperature frying may overcook lean fish and reduce beneficial nutrients. Instead of frying in oil, opt to use citrus juice or broth for cooking to keep fish moist and nutrient-rich. 

Adding more fish to your diet can help toward your weight-loss goals. But the bigger benefit to eating fish regularly is the heart-healthy omega-3 fats.

Which Fish has the Most Protein? 

All fish are rich in protein. The amount of protein in a piece of fish depends on the fat content. In general, a 4 oz piece of cooked fish contains between 22-28 grams of protein. If you buy fresh fish at the grocery store, look for 4-5 oz fillets. This is a standard serving that provides adequate omega-3s. Save room on your plate for vegetables, fruits and whole grains, too.

What is Fish Oil Good For?

A growing number of studies show actual fish consumption provides greater benefits than taking fish oil supplements alone. However, taking a supplement can be beneficial, especially if you’re someone who doesn’t eat fish. 

If you choose a fish oil supplement, be careful of what you pick. Most supplements won't contain enough of the essential omega-3 fats. The best fish oil supplements contain about one gram of EPA/DHA and make sure to watch portion size. Some supplements may require you to take several pills daily to reach the one gram amount. 

Taken in pill form, there are fish oil side effects like upset stomach and diarrhea. It can also interfere with allergies, blood thinners or provide excessive omega-6 and omega-9 fats that aren’t healthy.

Above all, if you’re considering taking a fish oil supplement, talk to your UnityPoint Health primary care provider.

What Does Fish Oil Do?

A powerhouse of omega-3 fatty acids (EPA and DHA), fish oil is most well-known for supporting heart health by reducing inflammation throughout the body and lowering high triglyceride levels.

Triglycerides are the most common type of fat (lipid) found in your body. They come from the extra calories you eat that your body doesn't need to use right away. These calories are converted into triglycerides and stored in your fat cells for energy later.

Beyond the heart, fish oil plays a big role in maintaining brain function and improving joint mobility by reducing stiffness.

Does Fish Oil Lower Cholesterol?

It’s a common misconception that fish oil significantly lowers "bad" LDL cholesterol. Its primary job is targeting triglycerides, which it can lower by 20% to 50%. While fish oil can slightly raise "good" HDL cholesterol, you should look to other supplements or medications if your main goal is specifically reducing LDL.

Is Fish Oil a Blood Thinner?

Yes, fish oil has mild anticoagulant properties, meaning it can make platelets less "sticky." While this is generally beneficial for preventing blood clots, talk to your doctor if you’re already on prescription blood thinners or having surgery soon.

Risks of Eating Raw Fish and Shellfish

Fish can contain salmonella and bacterium, which cooking kills when the temperature reaches 145 degrees, and the fish is opaque (not shiny and see through) and separates as flakes. Shellfish will open when cooked properly. If your shellfish doesn’t open, don't eat it. Food borne illness may occur if fish is kept too long after preparation, stored improperly or undercooked.

When it comes to the risk of eating raw fish, like sushi, there are some precautions. The source sushi comes from is extremely important. You’ll want to make sure it’s fresh and it’s been handled properly, or there's a risk of food poisoning. The fish used in sushi shouldn’t have any obvious odors and shouldn’t fall apart.

Fish to Avoid When Pregnant

Anyone who's pregnant, has a depressed immune system, or the very young or old should generally not eat sushi because of the bacteria raw fish may carry. Freezing the raw fish before preparing it can prevent some problems, but not all.

Pregnant individuals should also avoid shark, King Mackerel, swordfish and tilefish due to higher mercury content. Albacore tuna does have some mercury, but eight ounces of albacore tuna per week is generally safe for anyone who's pregnant. Troutner says the source of the fish is important in picking safe seafood. Pregnant individuals can check with local health departments before eating local fish to determine if mercury is in the area’s fish supply. 

If you're pregnant and have questions, talk with your care team to discuss what's best for you.

Introducing Kids to Fish

Early introductions are key for all flavors with kids — fish is no different. Having kids try fish at an early age (generally by the age of one) can set kids them up to enjoy this flavor for years to come. Like other foods, it may take several attempts for little ones to accept the taste, but consistency is key. Once you introduce fish to your child, make sure you serve it routinely.

Although fish sticks are commonly considered “kid friendly,” make sure you check the type of fish in the product and watch for sodium and added fat in the breading. Check the food label to understand the serving size. It’s a good idea to avoid product with more than 400 mg of sodium per serving or more than 3 grams of saturated fat per serving. 

If you have questions about your child’s diet, talk to their primary care doctor. 

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