Haddock is an excellent fish choice. It delivers nearly 29 grams of protein per fillet with only 122 calories and less than a gram of fat, making it one of the leanest protein sources available. It’s also low in mercury, mild in flavor, and versatile enough to work in almost any recipe that calls for white fish.
Nutritional Profile
A single steamed haddock fillet (about 140 grams) packs 28.8 grams of protein for just 122 calories and 0.8 grams of fat. That protein-to-calorie ratio is hard to beat, even among other fish. Beyond the macros, haddock is a standout source of two nutrients many people fall short on: vitamin B12 and selenium. One fillet provides 121 percent of your daily value for B12, which your body needs to make red blood cells and maintain nerve function. The same fillet covers 83 percent of your daily selenium needs, a mineral that supports thyroid health and acts as an antioxidant. You’ll also get about 32 percent of your daily phosphorus.
The one area where haddock doesn’t shine is omega-3 fatty acids. It contains roughly 0.2 grams of omega-3s per 100-gram serving, which is a trace amount compared to fatty fish like salmon or mackerel. If you’re eating fish primarily for heart-healthy fats, haddock won’t deliver much on that front. But if you’re after high protein with minimal calories and fat, it’s a top-tier option.
How Haddock Compares to Cod
This is the comparison most people want, since haddock and cod are the two most common white fish at the grocery store. Nutritionally, they’re nearly identical: both hover around 100 calories per serving with similar protein content and very little fat. The meaningful differences are small. Haddock has more vitamin B12, while cod edges ahead slightly in omega-3 content and has a bit less sodium.
The real difference is on the plate. NOAA Fisheries describes haddock as slightly sweet with a finer, more delicate flake than cod. Cod has a denser, firmer texture that holds up better in dishes like fish tacos or fish and chips. Haddock’s tenderness makes it ideal for baking, broiling, or poaching. If you’ve had traditional British smoked haddock (finnan haddie), you already know its flavor has a subtle sweetness that cod lacks.
Mercury and Safety
Haddock is one of the lowest-mercury fish you can buy. FDA testing of 50 Atlantic haddock samples found an average mercury concentration of just 0.055 parts per million. For context, the FDA considers fish with mercury levels below 0.15 ppm to be among the “best choices,” and haddock sits well under that line. You can safely eat two to three servings per week without concern, including during pregnancy.
When cooking, treat haddock like any other fish fillet: it’s done at an internal temperature of 145°F, or when the flesh is opaque and flakes easily with a fork.
Taste and Cooking
Haddock has a clean, slightly sweet flavor that’s milder than most fish but not as bland as tilapia. Its texture is firm enough to hold together during cooking but tender enough to flake apart beautifully when it’s done. The flake is finer than cod’s, which gives it a more delicate mouthfeel.
This makes haddock forgiving for home cooks. It works well baked with herbs and lemon, pan-seared with a light crust, broiled, or poached in broth. It’s a natural fit for chowders and fish pies. The mild flavor means it takes on seasoning and sauces easily without competing with them. The main thing to avoid is overcooking, which dries it out quickly given how lean it is. Pull it from heat as soon as it flakes, and you’ll have a moist, tender fillet every time.
Who Haddock Works Best For
Because haddock is essentially pure protein with almost no fat or carbohydrates, it fits comfortably into nearly any dietary pattern. It works for low-carb and keto eating, calorie-controlled diets, and heart-healthy plans like DASH. If you’re trying to hit a high protein target without adding much else to your daily totals, haddock is one of the most efficient ways to do it.
It’s also a solid entry point for people who don’t love “fishy” fish. The mild, sweet flavor and lack of oiliness make it approachable for picky eaters and kids. The tradeoff is that you won’t get the omega-3 benefits of fattier fish, so if heart health is a priority, consider rotating haddock with salmon, sardines, or mackerel throughout the week.
Sustainability
Haddock is in a middle zone when it comes to sustainability. Seafood Watch currently rates no haddock fisheries as a “best choice” (green), but none carry a red “avoid” rating either. Most fall in the yellow category, meaning the fisheries are reasonably well managed but have some concerns around population levels or bycatch.
Your best bet is to buy haddock caught in U.S. waters, specifically Georges Bank or the Gulf of Maine, or look for the Marine Stewardship Council (MSC) certification on the label. The fishing method matters too. Haddock caught with handlines or pole-and-lines has fewer bycatch impacts than haddock caught with bottom trawls or longlines, which can drag along the seafloor and catch non-target species. Most haddock at the supermarket is trawl-caught, so the MSC label is the simplest way to choose a more responsible option.