Flounder vs. Tilapia: 6 Differences & Which Is Better?

As a Registered Dietitian, it is my role to educate people on the pros and cons of different food choices, especially when it comes to their protein sources.

While fish might seem like they all have the same qualities, they have several differences. So, today we’re going to discuss flounder and tilapia. 

So which is better: flounder or tilapia? While flounder has a higher micronutrient content and is lower calories (-26 kcal), tilapia is a better option since it offers more protein in the same amount of food (+7.7 g).

A higher protein fish like tilapia gives you greater satiety, helps you maintain your muscle mass, and increases (slightly) your metabolism. 

While tilapia is a better option, this doesn’t mean that flounder is an awful choice to make. It is still an excellent lean protein source. In this article, I will explore the differences between flounder and tilapia. 

Flounder vs. Tilapia: Nutritional Information

In the following table, you can find the nutritional content of 100 grams of raw flounder and tilapia. 

Calories 

Flounder has a lower caloric content than tilapia. It has 26 kcal fewer calories per 100 grams. 

While this doesn’t sound like a significant amount, for someone trying to lose weight it can be helpful to select the lower calorie option. 

Protein

Tilapia has a higher protein content compared to flounder. In 100 grams, you get 7.7 grams more protein in tilapia than in flounder. 

This is a significant difference when it comes to protein consumption. 

Why is this important? 

Protein plays a crucial role in our bodies since it helps maintain muscle mass, increases your satiety (feelings of fullness), and can slightly increase your metabolism. 

This means that it is important to pay attention to your protein intake, and in my experience as a Registered Dietitian, most people have trouble reaching their daily requirements. 

If you prefer flounder over tilapia, it doesn’t mean that you cannot include it. It just means that you need to compensate with a larger piece to reach your protein requirements throughout the day. 

However, for those who get full very easily, I recommend having tilapia over flounder due to the protein content since it might be harder to increase the portion size. 

Fats

The fat content is very similar between flounder and tilapia. Flounder has slightly more fat (+0.2 g) compared to tilapia. However, this is not a significant difference

Also, they are both low in saturated fats. A high intake of saturated fats can increase your risk of developing heart disease. 

So if you’re trying to watch your saturated fat intake (which most of you should be), you can rest assured that they are both great lean protein sources. 

Micronutrients

The micronutrient profile is one of the biggest differences between flounder and tilapia. Tilapia has a higher micronutrient content compared with flounder. 

In the following table, you can find the complete micronutrient breakdown of each fish. 

Here are the top nutrients flounder has and its benefits

• Vitamin D. It helps regulate the absorption of calcium and phosphorus making it essential for bone health. Also, research shows that it can have an impact on your immune system. A study saw that people who had a deficiency of vitamin D, has a mortality rate of 16% due to COVID19 complications, compared to only 9% for people who had adequate levels of vitamin D. 

• Phosphorus. It is part of our bone structure, making it essential for bone health. Also, it helps regulate the absorption and usage of vitamins from the B complex and vitamin D. 

Here are the top nutrients tilapia has and its benefits

• Magnesium. It has an important role in exercise and performance. A study done in women, saw that those that had a higher magnesium intake (>350 mg per day) has a 2.6% increased power that those that had a lower magnesium intake. 

• Selenium. It is a powerful antioxidant that helps reduce inflammation in the body, leading to better post-workout recovery. Also, selenium is good for heart health. In a study, people who had a 50% increase in selenium concentrations saw a decrease of 24% in the risk of coronary heart disease. 

Flounder vs. Tilapia: 6 Differences

1. Taste and Texture

Flounder and tilapia have somewhat different textures and flavors (although not a huge difference). 

Tilapia has a very mild flavor and tender texture. It also has a flaky texture that easily melts in your mouth. 

While flounder has a similar taste to tilapia, it has a sweeter flavor and is moister than tilapia. It also offers the same flaky texture that you get from tilapia. 

Both are great to combine with any flavor since they don’t have an overpowering taste. This means you can combine them with any spice, herb, or sauce.

Winner: tilapia

They have very similar textures and flavors. It all comes down to personal choice, which in my case, I would give it to tilapia. 

2. Cooking Methods

One benefit of both fishes is that they are easy to cook. Since they have a similar texture and flavor, they don’t require a lot of food prep. Both fish are not very thick fish and typically take 10-15 minutes to cook a filet. 

You can cook them in the oven, pan fry them, or place them in the air fryer. 

One of the most significant differences between them is the defrost time though. While tilapia can take 1-2 days to defrost, flounder has a faster defrosting time (8-10 hours). 

Winner: flounder

Even though they have very similar cooking methods and time, it takes less time to defrost flounder. Making it the winner in this category. 

3. Costs

There is a significant difference in costs in flounder vs. tilapia. However, it also varies according to the store. 

The following table compares the cost for some of the top grocery stores in the US and the price per pound for each fish. 

As you can see, the difference if you get your products at Walmart is not very significant. There is only a $0.37 difference. However, in other stores like Target, the difference is more significant. We find a $1.40 difference. 

Unlike in our comparison between cod vs. tilapia, where we saw that cod was twice as expensive than tilapia, when it comes to flounder and tilapia, you probably don’t need to worry about the cost as much, moreso than trying to pick and choose where you buy it from.  

Another thing to consider is that flounder is harder to find. Not all of the stores have flounder in their selection of fish. Grocery stores like Costco and Whole Foods didn’t have a selection of flounder to compare it with. 

Winner: tilapia

It has a lower cost in most stores, and it is easier to find. 

4. Omega-3 and Omega-6

Omega-3 and omega-6 fatty acids are essential to the body since they cannot be produced internally. This means that you need to consume them through the diet. 

One of the benefits of omega-3 fatty acids is to reduce inflammation. Thanks to its anti-inflammatory properties, it can enhance your recovery rate (especially if you add it after your workout), reduce your pain, and improve gut health. 

On the contrary, omega-6 fatty acids are pro-inflammatory. Therefore, too many omega-6 fatty acids lead to an excess of inflammation in the body, leading to weight gain, poor digestion, and poor sleep. 

Studies show that people have a 16:1 omega-6 to omega-3 ratio. That is why high levels of inflammation are often seen in people nowadays. In reality, the ratio should be 2:1 omega-6 to omega-3. 

To compensate for the increased intake of omega-6 fatty acids, we need to increase the sources of omega-3. 

Flounder has a higher omega-3 content (253 mg) than tilapia (220 mg). Also, flounder has a lower omega-6 content (8 mg) than tilapia (210 mg), making it the better choice for reducing inflammation. 

However, this doesn’t mean that you cannot consume tilapia. It means that you need to be careful about balancing out other sources of omega-6. If you are going to add tilapia, reduce the intake of high sources of omega-6 like vegetable oils, peanuts, and corn oil. 

Winner: flounder

Flounder has a lower omega-6 and a higher omega-3 content. 

5. Mercury

Mercury is on the mind of many people when it comes to adding fish to their diets. High mercury exposure could lead to symptoms like depression, fatigue, headaches, tremors, and memory problems. 

The FDA classifies fish according to their mercury content. Both tilapia and flounder are considered low mercury fish. Meaning that you can consume them 2-3 times per week without worrying about getting mercury poisoning. 

Winner: tie

They are both fish considered low in mercury. 

6. Environmental Sustainability

Since tilapia is a very popular fish, most of it is raised on farms to provide for the high demand. 

While it is not always the case, farm-raised animals tend to be higher in antibiotics and growth hormones. Additionally, they are often fed corn and soy products, leading to a higher content of omega-6. 

On the other hand, there are not many farms for flounder (which is why it is not so often found in stores). In addition, since the demand is not so high, the conditions where they are kept are not as bad as those found on tilapia farms. 

Winner: flounder

They tend to have better farm conditions and are less likely to be high in antibiotics. 

Flounder vs. Tilapia on Different Diets

Keto

You can add either flounder or tilapia to a keto diet. They are good sources of lean protein and are carb-free. With that being said, you need to add fat sources to compensate for the lack of this macronutrient. 

Since people in a ketogenic diet rely on fats for energy, add healthy fats like avocado, olive oil, or olive to balance the dish if you have tilapia or flounder. 

Paleo

Fish makes an excellent protein source for the paleo diet. Whenever possible, choose wild-caught over farmed-raise since the latter can have a higher omega-6 content. The paleo diet focuses on a high omega-3 content. 

If you cannot add wild-caught, focus on adding other high omega-3 sources to your diet like chia seeds, hemp seeds, or flaxseeds. 

Intermittent Fasting 

Having protein as your first meal after fasting can prevent your sugar levels from spiking first thing in the day. Whether it is flounder or tilapia, you can add them to break your fast or have them throughout the day. 

If you are breaking your fast, add healthy fats like avocado, olive oil, nuts, and healthy carbs like brown rice or sweet potatoes (remember to add a good portion of non-starchy veggies).

Low-Sodium Diet

Both fish are good to add to a low sodium diet if there are fresh. Canned fish can be high in sodium, affecting the results of a low sodium diet. 

If you choose canned fish, make sure that it has less than 150 mg per serving (100 grams) to ensure low sodium. 

Vegan

Neither options are suitable for a vegan diet. Since they are animal products, they are eliminated from this type of diet. If you are looking for a replacement, you can opt for jackfruit, tofu, or mushrooms. 

Low FODMAPs

Tilapia and flounder are options that are low in FODMAPS, making it ideal for those who need to follow a low FODMAP diet. However, if you are buying them canned or marinated, ask the ingredients to ensure that it doesn’t have any food that could cause symptoms. 

Flounder vs. Tilapia: Which Is Better For Weight Loss?

Both flounder and tilapia are excellent choices for weight loss. They are high in protein and low in fat.

However, flounder would be a better choice if you need to pick one due to its lower caloric content. In 100 grams, flounder has 26 fewer calories than tilapia. 

Nonetheless, this doesn’t mean that you cannot consume tilapia.

Even though it has slightly more calories, it has a higher protein content. Protein helps increase your fullness levels, and it is harder to digest for the body, meaning that it burns more calories to process it. 

Flounder vs. Tilapia: Which Is Better For Muscle Gain?

Tilapia is a better option for weight gain since it is higher in calories and protein content than flounder. Tilapia has 26 more calories and 7.7 grams more protein than flounder.

However, tilapia is considered a low-calorie food, meaning you need to add other high-calorie foods to reach a caloric surplus. 

Remember that while protein is an essential component in the equation of weight gain, the calories you eat throughout the day are equally important. Adding other high-calorie foods throughout the day will be crucial for your results. 

If you are going to switch between flounder and tilapia, remember that flounder has significantly less amount of protein.

Thus, you would need to increase the portion to reach your protein requirements or compensate with another protein source later in the day (protein shake, eggs, Greek yogurt) 

Practical Recommendations: Eating Flounder vs. Tilapia

Change Your Foods

The key to optimal nutrition is to have a diet with different foods. Each food has a specific nutrient and benefit. If we eat the same thing every day, we won’t be getting that variety in nutrients. 

Whether you like only flounder or tilapia, it is important to have variety in your protein sources. Add other fish like cod, tuna, and salmon to ensure that you get enough nutrients throughout the week. 

Choose The One You Like

One of the most important things I tell my clients is to choose the foods they like and make you happy. Even if tilapia is a good protein option, you don’t need to include it if you don’t like it. 

Forcing yourself to eat a food is an unnecessary practice that won’t make you enjoy the meals you are having. 

Track Everything

No matter which protein option you choose, you need to track the size with a weight scale to ensure that you are getting enough protein throughout the day.

Since flounder contains less protein than tilapia, this will be crucial to make sure that you don’t go below your requirements. 

Also, use a calorie counter app to help you count how many grams of protein you are having throughout the day. This will help you determine if you need to compensate for extra protein if you add flounder. 

Try Different Recipes

The thing with fish is that most people don’t like the “fishy” taste. While fresh fish shouldn’t have this smell or taste, you can always find different recipes to add some extra flavor to your proteins. 

• Baked flounder with lemon and butter
• Baked flounder with panko and parmesan
• Oven-baked tilapia recipe
• Tilapia with olives, mushrooms, and tomatoes

Frequently Asked Questions

Does Flounder Taste Like Tilapia?

Yes, flounder has a similar taste and texture to tilapia. However, it has a sweeter taste compared to tilapia. Either option pairs well with any spice, herb, or sauce you want to use to increase the flavor. 

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