Mackerel is a fatty fish, so it contains substantially more fat than cod or pollock—and that fat is also where much of its omega-3 value comes from. Cooked Atlantic mackerel (Scomber scombrus) combines almost 24 g protein per 100 g with a substantial amount of EPA and DHA.
Mackerel is a good example of a food where fat explains both the calories and much of the nutritional interest. Comparing it with a white fish only by calories can be misleading: white fish is very lean, while Atlantic mackerel provides substantial unsaturated fat and long-chain omega-3s. The better choice depends on what the meal needs rather than on assuming that the lowest calorie number is always nutritionally superior.
Cooked Atlantic mackerel nutrition
| Per 100 g cooked | Approximate amount |
|---|---|
| Calories | 262 |
| Protein | 23.9 g |
| Total fat | 17.8 g |
| Saturated fat | 4.2 g |
| EPA | ~0.50 g |
| DHA | ~0.70 g |
| Vitamin B12 | ~19 mcg |
| Selenium | ~52 mcg |
EPA and DHA add up to about 1.2 g per 100 g. NIH gives a similar serving reference: 3 ounces (85 g) cooked Atlantic mackerel contains about 0.43 g EPA and 0.59 g DHA, just over 1 g combined.
Per-100-gram values make species easy to compare, but a 4- to 5-ounce serving is closer to a meal. At that size, protein readily exceeds 25–30 grams and EPA plus DHA can be substantial. Cooking method adds another variable. Frying or rich sauces raise calories, while baking, broiling, grilling, or steaming keep the comparison closer to the fish’s own composition.
Why is mackerel higher in calories than white fish?
Fat explains most of the gap. Cooked cod can be roughly 90–105 calories per 100 g with less than 1 g fat, while Atlantic mackerel reaches 262 calories and nearly 18 g fat. That is around 160 more calories per 100 g, but much of the mackerel fat is unsaturated and includes marine omega-3s.
Vitamin B12 is especially concentrated in mackerel, and selenium is another notable micronutrient. Those nutrients arrive alongside protein and marine fat, so the fish contributes more than omega-3 alone. You do not need to eat mackerel every day to obtain them. A varied diet can rotate different fish and shellfish with eggs, dairy, or other sources according to preference and dietary needs.
Protein is still highly concentrated
At 23.9 g protein per 100 g, a 150 g cooked serving provides about 35.8 g protein. It contains no carbohydrate and also provides substantial vitamin B12, selenium, phosphorus and magnesium.
Species identification prevents an important mistake because “mackerel” covers several different fish. Atlantic mackerel and some smaller mackerel species are listed among lower-mercury choices in U.S. guidance, while king mackerel is a different species with much higher mercury. Canned products often identify the common or scientific name. When there is uncertainty, that information is more useful than assuming all mackerel have the same contaminant profile.
Species matters dramatically for mercury
The common name “mackerel” covers very different fish. FDA/EPA classify Atlantic mackerel and Pacific chub mackerel as Best Choices for lower mercury. FDA’s technical data use an average mercury concentration of about 0.05 ppm for Atlantic mackerel.
King mackerel is a different species and appears in the Choices to Avoid category for the populations covered by the FDA/EPA advisory because of much higher mercury. Advice that simply says “mackerel” without identifying the species can therefore be misleading.
For canned mackerel, compare nutrition using drained weight when possible. Oil, water, or brine mainly change added fat and sodium around the fish. Draining an oil-packed can removes some surface oil but does not make it identical to a water-packed product. Some canned mackerel also includes soft edible bones that can contribute calcium, although that depends on the specific style and product.
Fresh versus canned
Canning preserves protein and omega-3s, but the packing medium changes calories and sodium. Oil-packed mackerel is more energy-dense, while brined products can contain considerably more sodium. Compare labels using the drained serving or per-100-g values.
Mackerel’s strong flavor makes moderate portions easy to use in salads, toast, pasta, grain bowls, or vegetable dishes. Pairing it with fiber-rich foods can build a balanced meal without needing an oversized serving. If sodium is the concern, fresh fish or a lower-sodium can may fit better; if mercury is the concern, species is the first question. Those are separate issues and the label helps answer them separately.
Bottom line
Atlantic mackerel is a concentrated source of protein, EPA, DHA and vitamin B12. Its higher calories compared with white fish come mainly from fat. For both nutrition and mercury guidance, identify the species rather than relying on the word “mackerel” alone.
In practical terms, Atlantic mackerel combines dense protein, marine omega-3s, B12, and selenium. Its higher calories compared with white fish are largely the result of more fat. Choose the species carefully, use a sensible portion, and read the packing medium on canned products. Those three steps make the nutrition comparison much more useful than ranking every fish by a single number.
Sources
- USDA FoodData Central — Atlantic mackerel, cooked, dry heat — Energy, protein, fat, EPA, DHA, vitamin B12 and mineral data for cooked Atlantic mackerel.
- NIH Office of Dietary Supplements — Omega-3 Fatty Acids — EPA and DHA per serving of cooked Atlantic mackerel.
- FDA/EPA — Advice about Eating Fish — Species-specific mercury categories distinguishing Atlantic/Pacific chub mackerel from king mackerel.