What Are the Health Benefits of Flounder?

Medically Reviewed by Kathleen M. Zelman, RD, LD, MPH on May 23, 2022
5 min read

Many types of fish are grouped under the name flounder. All of them are flat fish that live at the bottom of shallow seas. American plaice, halibut, and windowpane flounder are some of the species. They should be regular parts of your diet for their high protein content without many calories or fats. Flounder taste is sweet and mild, and this fish should be simply cooked to retain its flavor. Flounder has many health benefits and should frequently appear on your dinner table.

Flounder are flat fish that live in the sea. They're bottom-dwelling and lie on one side rather than the belly. Flounder feed on crustaceans, sea worms, and other small animals. Like other flat fish, both their eyes are on the right side of their body. Several species of flounder are harvested wild from the coasts around the U.S.:

  • American plaice (Hippoglossoides platessoides), also called dab. It is the smallest flat fish, weighing about 9 ounces (250 grams)
  • Winter flounder (Pseudopleuronectes americanus), also called blackback flounder and lemon sole 
  • Windowpane flounder (Scophthalmus aquosus), also called sand flounder 
  • Witch flounder (Glyptocephalus cynoglossus) also called grey sole
  • Yellowtail flounder (Limanda ferruginea)

Different flounder are found off the various coasts of the U.S. Adult flounder prefer living and feeding on the bottom of deep sandy or muddy-bottomed waters. American plaice and winter flounder are sustainable. Windowpane flounder is overfished but is no longer sought by fishermen. Witch flounder and yellowtail flounder are overfished, and overfishing is continuing.

Flounder is a low-fat, low-calorie protein source. It also provides vitamin B12, vitamin D, selenium, and omega-3 fatty acids. A 100-gram portion of raw flounder provides:

Protein. 18.84 grams of complete protein

Fat. a total fat content of 1.19 grams

Saturated fatty acids. 0.283 grams

Cholesterol. 48 milligrams

Carbohydrates and sugar. None

Selenium. 32.7 milligrams

Sodium. 81 milligrams

Flounder provides no dietary fiber. It is , however, a good source of iodine, providing 14.3 micrograms per 100 grams.

The Dietary Guidelines for Americans recommend that adults eat at least 8 ounces (230 grams) of seafood every week. Women who are pregnant or breastfeeding should have more. They should consume between 8 and 12 ounces (230 to 340 grams) per week of seafood known to have low mercury levels. Flounder is one of the fish that has low mercury content.

Protein is an important component of your diet. Protein foods are one of the six major food groups essential for good nutrition and health. Protein foods consist of meats, poultry, eggs, seafood, beans, peas, lentils, nuts, seeds, and soy products. Not all protein foods are the same. They vary in the amount of protein as well as fat and carbohydrate content.

Heart disease is a leading cause of death among adults. Eating large amounts of fats, especially saturated fats, is linked to heart disease. Red meat usually has significant amounts of fat and saturated fats, even if you get lean cuts. Beef, for example, has 27.7 grams of protein per 100-gram portion. But it also has 6.36 grams of fats, of which 2.47 grams are saturated fats.

Eating fish like flounder with adequate protein but low amounts of total fat (1.19 grams per 100 grams) and saturated fats (0.283 grams per 100 grams) is healthy. Reducing fats in your diet promotes health and lowers the risks of chronic diseases:

  • Less risk of heart disease
  • Lower blood cholesterol levels
  • Less risk of obesity
  • Lower blood pressure
  • Lower risk of type 2 diabetes
  • Lower risk of cancer of the breast and colon

Fish, especially oily fish, are rich in omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These are good for heart health.

It isn't necessary to stop eating meat, of course. But replacing meat with flounder (or similar seafood) once or twice a week will benefit your health.

Flounder are rich in nutrients essential for childhood brain growth and development. Children and pregnant and breastfeeding women should include it in their diet to get these nutrients:

  • Omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)
  • Iodine
  • Choline
  • Iron

Choline also helps in the growth and development of a baby's spinal cord. Flounder provide iron and zinc, needed for a child's maturing immune system. Flounder also provide children with other vital nutrients like protein, vitamin B12, vitamin D, and selenium.

Eating some sea creatures can be hazardous for humans. Flounder appear to be safe. They do not produce any toxins of their own. They also don't contain histamine, which can cause allergic reactions. Flounder harvested off the U.S. coast are free of drugs used in aquaculture. Some flounder are harvested by aquaculture and may contain drugs.

Though flounder are not poisonous or venomous, they can carry dangers. They can be parasite-infested and can absorb chemicals and pollutants from the water in which they live. The pollutant considered most dangerous is mercury. Methylmercury is an industrial pollutant often found in seawater and absorbed by fish. Eating such fish is harmful to health. It is especially dangerous for pregnant women, breastfeeding women, and children.

Flounder have very low amounts of mercury and appear to be safe in this regard. Flounder is included in the list of best choices among seafood. Pregnant and breastfeeding women and children should eat two or three servings a week of flounder a week to get its nutritional benefits.  

Flounder is usually sold whole, but you can also find fillets. Avoid flat fish during the spawning season (spring) because the meat is watery and thin. The best time to eat flounder is from September to May.

Fish spoils very quickly after removing from the refrigerator. When shopping, pick up flounder last of all. It's best to go home directly and put it in your refrigerator immediately. 

Flounder need simple cooking. Remove the fins and head, and then grill or bake whole. Add citrus, herbs, or butter as you like. Large flounder can be filleted or pan friend. 

Fried flounder. This is a simple and delicious way to serve flounder. Dredge a whole flounder in well-seasoned flour and pan-fry with olive oil and butter. Serve with lemon wedges, parsley, and sea salt.

Flounder Stuffed with Jumbo Lump Crabmeat. An elaborate dish, combining flounder fillets with egg whites, crabmeat, breadcrumbs, butter, and white wine.