Tuna vs. Mahi Mahi: Pros, Cons, Differences, & Which Is Better?

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Tuna and Mahi Mahi are both excellent protein options; however, one might be a better option for you based on your goals and preferences.

So, what are the differences between Tuna and Mahi Mahi? The main differences between Tuna and Mahi Mahi are that tuna is higher in calories (+23 kcal), protein (+5 g), nutrients (vitamin B6), and omega-3 fatty acids (+126 mg) per 100g serving. However, they both have a low saturated fat content, making them an ideal option for those looking to reduce their overall fat intake.

While tuna comes out on top in many areas, it’s important to get the full picture of how Mahi Mahi compares with tuna by comparing these fish across several nutritional data points.

As a Registered Dietitian, it’s my job to help my clients choose the best foods for their goals; while also educating them on the importance of variety in their diet.

In this article, I explore the pros, cons, and differences between tuna and Mahi Mahi to establish which one is the better option and how they can complement one another.

Tuna vs. Mahi Mahi: Nutritional Information

To decide whether Tuna or Mahi Mahi is the healthier option, I’ve laid out their nutritional information side by side to compare them. The following table gives you the nutritional information for 100 g of raw Mahi Mahi and tuna.

Calories 

Tuna and Mahi Mahi have different caloric contents, with tuna having 23 calories more than Mahi Mahi.

The higher caloric intake in tuna can benefit those looking to gain weight because it can help you achieve a caloric surplus (eating more calories than your body needs to maintain weight) more easily than Mahi Mahi.

Those looking to lose weight may gravitate towards Mahi Mahi over tuna because it’s lower in calories.

That said, you can still eat tuna if you want to lose weight or Mahi Mahi if you want to gain weight because what matters most is your total daily caloric intake. A 23-calorie difference won’t make or break your diet, but it does play a role.

Protein

Another difference between tuna and Mahi Mahi is their protein content with Tuna having 5g more protein than Mahi Mahi, making tuna the more satiating fish. 

Protein is important in your body since it helps you retain and/or gain muscle mass, and it helps you stay full for longer periods.

I recommend that you aim for 1g of protein per pound of bodyweight to ensure you’re getting enough protein to support your health and fitness goals.

To help you reach this protein target, it’s best to opt for higher protein options as often as you can. In this case, tuna would be more attractive because of its higher protein content.

If you chose Mahi Mahi over tuna, you should compensate for the lower protein content by adding 5g of protein in another meal or snack of the day.

Fats

There is no significant difference between the fat content of tuna and Mahi Mahi because there is only a 0.2g difference between the fish. Both tuna and Mahi Mahi are considered lean protein sources since they have less than one gram of fat per 100 g. 

When comparing the fat content, it’s important to evaluate the amount of saturated fat that these fish have because the type of fat matters more than the amount of fat.

This is because saturated fats should be limited, so a fish with more total fat but less saturated fat would be healthier than a fish with lower total fat but higher saturated fat.

When it comes to saturated fat, it’s best to have less than 7% of your total calories from saturated fat to avoid heart disease. For someone with a 2,000 calorie intake, this would be less than 15 grams daily. 

Both tuna and Mahi Mahi have the advantage of being low in saturated fats because they both have 0.2 g of saturated fat per serving, which isn’t significant enough to put you close to the upper limit.

Micronutrients

Another important area where there is a significant difference between tuna and Mahi Mahi are their nutrient profiles, with tuna having more concentrated amounts of each nutrient.

The following table summarizes the nutritional content of tuna and Mahi Mahi based on 100 g of food. Anything below 5% is considered low, while anything above 20% is considered an excellent nutrient source. 

Here are the top nutrients tuna has and their benefits:

• Niacin. A study showed that maintaining an adequate intake of niacin is important for the primary prevention of high blood pressure.

• Vitamin B6. For women, consuming vitamin B6 can help reduce symptoms of PMS. A study showed that women who took 50 mg of vitamin B6 and magnesium experienced fewer PMS symptoms. Additionally, studies show that people with lower levels of vitamin B6 in their bodies tend to have more depressive symptoms. 

• Thiamin. It helps convert your carbs and fats into usable energy to be used by the body for basic functions and daily activities.

It should be noted that tuna is also high in selenium, but not as high as Mahi Mahi (-14%).

Here are the top nutrients Mahi Mahi has and their benefits:

• Selenium. Low levels of selenium have been linked to an increase in developing symptoms of hypothyroidism. Additionally, studies show that selenium can help reduce asthma symptoms. 

• Vitamin B12. It helps produce red blood cells, which are in charge of transporting oxygen and nutrients throughout the body. 

It should be noted that Mahi Mahi is also high in Niacin and Vitamin B6 but not as high as tuna (-11%, -21%).

Tuna vs. Mahi Mahi: 5 Differences

1. Taste and Texture

There is a considerable difference in taste between tuna and Mahi Mahi because Mahi Mahi has a more subtle sweet taste, whereas tuna has a strong buttery taste.

Mahi Mahi also has a softer and flakier texture that is better for fish tacos or fish cakes. Tuna has a firmer texture that is better for dishes like poke or sushi.

Even though tuna and Mahi Mahi have different textures and flavors, they both pair well with all herbs and spices.

Winner: Tuna

Tuna has a buttery and firmer texture that can be used in cooked or raw dishes, whereas the texture of Mahi Mahi limits its use. That being said, there are many people that can’t stand the taste/smell of tuna, so this will come down to personal preference.

2. Cooking Methods

Another difference between tuna and Mahi Mahi is their cooking methods because tuna can be found fresh or canned, but Mahi Mahi is only available in fresh forms.

One of the advantages of canned tuna is that it’s a convenient protein source when you don’t have time to cook. It can be thrown into any dish to bump up its protein content.

Additionally, tuna can be eaten raw, baked, grilled, or pan-fried, making it a versatile fish, whereas Mahi Mahi, is typically only fried or baked.

Winner: Tuna

Tuna is more versatile than Mahi Mahi because it can be eaten raw, canned, baked, grilled, or pan-fried, making it a convenient protein source no matter the situation.

3. Costs

Another significant difference between tuna and Mahi Mahi is their costs. On average, tuna tends to be more expensive than Mahi Mahi by $5 to $19, depending on where you shop. 

Although there is a significant difference in price between these fish, both fish are still considered cheap proteins compared to other whole food protein sources (like chicken or beef).

In the following table, I compare the prices of tuna and Mahi Mahi for one pound of each product. 

If you’re shopping for tuna, then it’s best to buy it from Walmart or Target and to avoid buying it at Whole Foods. If you’re shopping for Mahi Mahi then Target, Costco, and Whole Foods are all great options.

Winner: Mahi Mahi

Mahi Mahi is available at a lower cost than tuna in most stores, so it is considered the most cost-effective fish.

4. Omega-3 and Omega-6

There is also a significant difference between the omega-3 content of tuna and Mahi Mahi, with tuna having 126mg more Omega-3 than Mahi Mahi. However, both have a good omega-3 intake, with a low omega-6 content, which decreases inflammation. 

Omega-3 and omega-6 fatty acids are essential fats since your body can not produce them, meaning you need to get them through your diet. 

Omega-6 is required in lower amounts than Omega-3 because it encourages inflammation, whereas Omega-3 is anti-inflammatory.

Your body needs some inflammation to make changes. For example, if you cut yourself, your inflammation levels rise to help you get cured and healed. However, the problem arises when there is more inflammation than your body can handle. 

Omega-6 fatty acids are pro-inflammatory, while omega-3 fatty acids are anti-inflammatory. 

To avoid having a pro-inflammatory state, the omega-6 to the omega-3 ratio recommended is 2:1 (or even 1:1). 

However, studies have shown that, on average, people consume an omega-6 to omega-3 ratio of 16:1. 

Having a higher inflammatory state can lead to poor digestion, poor sleep, and trouble in the weight department (more challenging to lose weight). 

To help balance this ratio, it is crucial to include foods high in omega-3 and low in omega-6, which makes both tuna and Mahi Mahi an excellent choice. 

Tuna has 243 mg of omega-3, while Mahi Mahi has 117 mg. Tuna has 126 mg more omega-3 content, making it the better option to help reduce inflammation. 

While there are no records on the content of omega-6 in Mahi Mahi. Tuna is considered a food very low in omega-6 fatty acids since it only has 9 mg. 

Winner: Tuna

Tuna has 126 mg more omega-3 fatty acids than Mahi Mahi and a low omega-6 content since it only has 9 mg per 100 g. 

5. Mercury

Mercury levels are important to assess to determine how often you should include these fish in your diet. Both tuna and Mahi Mahi have moderate mercury levels, meaning you can safely consume up to two servings per week.

A high mercury intake can lead to symptoms like fatigue, depression, headache, tremors, and memory problems. 

The FDA created a table for you to reference to determine if a fish is low, moderate, or high in mercury. The table recommends how often you can safely consume each type of fish.

Winner: Tie

They are both moderate in mercury, meaning it’s better to include them only twice per week to avoid mercury poisoning. 

Tuna vs. Mahi Mahi on Environmental Sustainability

There is a strong relationship between how fish are acquired (farm-raised or wild-caught) and environmental sustainability. Both tuna and Mahi Mahi can be farm-raised or wild-caught.

Farmed-raised fish are bred in small spaces in rivers or the ocean; because of this, they are more likely to get sick and transmit diseases. Farmers then provide these fish with antibiotics to ward off any diseases. However, it’s common for these antibiotics to spread through the water to other wildlife. 

On the other hand, wild-caught fish are obtained from their natural habitats, which is more sustainable for the environment and reduces the chances of human antibiotics becoming less effective over time.

Additionally, studies have shown that wild-caught fish have more omega-3 content than farm-raised fish (+50%).

Both tuna and Mahi Mahi can be found farmed-raised and wild-caught in major stores, so it’s important to do your part and shop for wild-caught varieties as often as possible.

Winner: Tie

Both tuna and mahi mahi are equal regarding environmental sustainability.

Tuna vs. Mahi Mahi on Different Diets

Keto

The keto diet focuses on increasing your fat intake and lowering your carb intake. Tuna and Mahi Mahi are both low in carbs, but they’re not high enough in fat to complement the keto diet as well as salmon would.

Because tuna and Mahi Mahi are very low in fat, you would need to compensate by consuming them with a fat source like avocado, nuts, seeds, or olive oil. 

Winner: Tie

Tuna and Mahi Mahi are both low in fat, so they’re tied for their value on the keto diet.

Paleo

The main goal of the paleo diet is to reduce inflammation in your body, and because Omega-3s help to reduce inflammation, they are a key nutrient for the paleo diet. Both tuna and Mahi Mahi have omega-3s to contribute.

Tuna is the best option since it has a higher amount of omega-3 and very low omega-6 content. 

If you want to add Mahi Mahi, compensate by adding other foods high in omega-3, like chia seeds, hemp seeds, and flaxseeds. 

Winner: Tuna

It has a higher omega-3 content than Mahi Mahi and low omega-6 content, making it ideal for reducing inflammation. 

Intermittent Fasting 

Intermittent fasting requires you to eat all of your calories within a certain window (i.e 12 pm-6 pm), but one of the challenges of this diet is consuming an adequate amount of protein. 

With a shorter eating window, people usually reduce their protein intake, so including fish like tuna and Mahi Mahi can be beneficial to help increase your protein intake.

Tuna is the better option because it has more protein than Mahi Mahi, so it will be more helpful if you’re struggling to hit your protein target.

On the other hand, if you don’t have any problems with reaching your protein intake, you can add Mahi Mahi since it’s lower in calories, and typically the goal of intermittent fasting is to lose weight.

Winner: Tuna

Tuna is higher in protein, helping you achieve your protein requirements when you have a limited eating window. 

Low-Sodium Diet

Both fresh tuna and Mahi Mahi are low in sodium, making them excellent options when trying to reduce your sodium consumption.

However, since one of the most common ways to have tuna is canned, you should be mindful of how much sodium it contains. I recommend looking for canned tuna with less than 140 mg of sodium.

My favorite low-sodium canned tuna is Bumble Bee Prime Solid White Albacore Tuna Low Sodium in Water, which only has 65 mg of sodium per serving.

Winner: Mahi Mahi

Mahi Mahi in all its forms is low in sodium, whereas canned tuna will always bring more salt to the table.

Low FODMAPs

Since tuna and Mahi Mahi don’t contain any carbs. They won’t provide you with FODMAPs, which could affect your irritable bowel syndrome (IBS) symptoms. 

However, you should be mindful about how you’re cooking your fish because it’s often the flavor enhancers like garlic and onions that are high in FODMAPs, and can cause you to flare up.

• Related Article: 15 High Calories Low FODMAP Foods

Winner: Tie

Tuna and Mahi Mahi are low in FODMAPs, making them an excellent choice for those with IBS. 

Tuna vs. Mahi Mahi: Which Is Better For Weight Loss?

Mahi Mahi is a better option for weight loss because it is lower in calories than tuna (-23 calories). However, tuna has more protein to keep you satiated so that you’re not snacking as much throughout the day.

Mahi Mahi is the better option if you’re struggling to keep your calories under your daily goal because it has fewer calories.

On the other hand, tuna is the better choice if you’re struggling to reach your protein target and feeling hungry between meals because it’s higher in protein than Mahi Mahi.

Ultimately, both fish can be just as effective for weight loss as long as your calorie intake is on point and you can adhere to your diet long enough to reach your goals.

Winner: Tie

Tuna and Mahi Mahi are tied when it comes to encouraging weight loss because they eah have their own strengths, so it depends on what you struggle with the most in your diet.

Tuna vs. Mahi Mahi: Which Is Better For Muscle Gain?

Tuna is the better option when you are looking to gain muscle because it’s higher in calories and higher in protein. 

To gain weight, you need to be in a caloric surplus, which means eating more calories than your body needs to maintain weight. Since tuna has 23 calories more than Mahi Mahi, it can make it easier to achieve that caloric surplus.

Additionally, an adequate protein intake is required to build muscle, and tuna has more protein than Mahi Mahi (+5 g).

To really encourage muscle gain, you still need to add other food sources like carbs (rice, potatoes, and yams), healthy fats (avocado, nuts, and seeds), and some fruits and veg to ensure that you’re consuming enough calories to put on mass and enough nutrients to stay healthy.

Winner: Tuna

Tuna has more calories and protein than Mahi Mahi, which helps you reach a caloric surplus and promote muscle gain. 

Practical Recommendations: Eating Tuna vs. Mahi Mahi

Mix Them Up

Although tuna has more health benefits than Mahi Mahi, their nutrient profiles are slightly different, so it’s important to include both in your diet (if you like them both) to ensure that you’re getting a variety of nutrients.

The best way to ensure that you’re getting all of the essential nutrients your body needs is to increase the variety of foods in your diet. This means that instead of focusing on just one fish, have several protein sources throughout the week. 

For example, if you have tuna today, have Mahi Mahi tomorrow, and chicken or tofu the day after.

Choose The One You Like

One of the most important things I teach my clients is to prioritize foods that they enjoy eating. Even though tuna is a better option in many ways, if you don’t like it, you shouldn’t force yourself to have it. 

People are way more successful with their goals when they’re enjoying the foods they’re eating, so it’s more important to choose foods you like.

Cook Them In Different Ways

Oftentimes, people avoid having fish simply because they don’t know how to cook it, but one of the benefits of tuna and Mahi Mahi is that they can be cooked in a variety of ways with different herbs and spices. 

Here are some recipes to help you include tuna and Mahi Mahi in your diet. 

• Tuna cakes with lemon
• Ahi tuna tacos
• Mahi Mahi fish tacos
• Tomato basil Mahi Mahi

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• Mahi Mahi vs. Cod