A 3-ounce cooked fillet of mahi mahi contains about 20 grams of protein and just 93 calories. That makes it one of the leanest, most protein-dense fish you can buy, with less than 1 gram of total fat per serving.
Protein Content by Serving Size
Raw mahi mahi provides roughly 23.7 grams of protein per 100 grams. Once cooked, water evaporates and the flesh compresses, concentrating the protein into a smaller portion. A standard 3-ounce cooked fillet (about the size of a deck of cards) delivers around 20 grams of protein. A more typical dinner portion of 6 ounces cooked lands you at approximately 40 grams, which covers a significant chunk of most people’s daily protein needs in a single sitting.
For every 10 grams of protein you eat from mahi mahi, you’re taking in only about 46 calories. That ratio is hard to beat, even among other lean proteins like chicken breast or cod.
How Mahi Mahi Compares to Other Fish
Mahi mahi actually edges out salmon in raw protein content: 23.7 grams per 100 grams versus salmon’s 22.1 grams. The real difference shows up in total calories. Salmon runs about 206 calories per 100 grams because of its higher fat content, while mahi mahi comes in at 109. That means you get 22 grams of protein per 100 calories from mahi mahi, compared to just 11 grams per 100 calories from salmon.
This doesn’t make mahi mahi “better” than salmon. Salmon’s extra calories come from omega-3 fats that are genuinely beneficial. But if your primary goal is hitting a high protein target without adding many calories, mahi mahi is the stronger choice. It sits in a similar category to tilapia and cod as a go-to lean white fish.
Amino Acid Quality
Mahi mahi is a complete protein, meaning it supplies all nine essential amino acids your body can’t produce on its own. Lysine is the most abundant amino acid in mahi mahi, followed by leucine. Leucine is particularly relevant if you’re interested in muscle building, since it’s the amino acid most directly involved in triggering muscle protein synthesis after a meal. Glutamic acid and aspartic acid round out the profile as the dominant amino acids overall.
Other Nutrients Worth Knowing
Protein is the headline, but mahi mahi also delivers a strong lineup of micronutrients. A 100-gram raw serving contains 36.5 micrograms of selenium, which covers about two-thirds of the daily recommended intake. Selenium supports thyroid function and acts as an antioxidant. Mahi mahi is also a good source of vitamin B12, vitamin B6, niacin, potassium, and phosphorus. B12 is especially worth noting if you rely on fish as a primary protein source, since it’s critical for nerve function and red blood cell production.
Where mahi mahi falls short compared to fattier fish is in omega-3 fatty acids. A 3-ounce raw serving provides about 17 milligrams of EPA and 75 milligrams of DHA. That’s a fraction of what you’d get from salmon or mackerel, which can deliver over 1,000 milligrams combined per serving. If omega-3 intake is a priority, mahi mahi alone won’t get you there.
Mercury Levels
Mahi mahi has a mean mercury concentration of 0.178 parts per million, based on FDA testing data. That places it in a moderate range: higher than shrimp, tilapia, or salmon, but well below high-mercury fish like swordfish, shark, or king mackerel. For most adults, eating mahi mahi two to three times a week stays well within safe limits. Pregnant women and young children may want to keep servings to one or two per week and mix in lower-mercury options.
Cooking Tips to Preserve Protein
Cooking method doesn’t significantly change the protein content of mahi mahi. Grilling, baking, broiling, and pan-searing all produce roughly the same protein per serving, since protein is heat-stable and doesn’t break down during normal cooking. What changes the nutritional profile is what you add. A grilled fillet with lemon stays at about 93 calories and under 1 gram of fat. Batter-frying that same fillet or drenching it in butter sauce can double or triple the calories without adding any extra protein.
Mahi mahi’s firm texture holds up well to high-heat methods like grilling and broiling, which makes it easy to keep preparation simple. Seasoning with herbs, citrus, or a light marinade preserves the lean protein advantage that makes this fish appealing in the first place.