Halibut is not a fatty fish. With only about 2.3 grams of total fat per 100-gram serving, it falls squarely in the lean fish category. For comparison, Atlantic salmon contains roughly 12 grams of fat per 100 grams, making it six times fattier than halibut.
What Makes a Fish “Fatty”
Fish are generally split into two camps: lean and fatty (sometimes called oily). Fatty fish like salmon, mackerel, sardines, and herring store fat throughout their muscle tissue, typically containing 5 grams or more of fat per 100-gram serving. Lean fish like halibut, cod, and tilapia carry most of their fat in the liver and have much less in the flesh you actually eat.
Halibut’s 2.3 grams of fat per 100 grams puts it well below that threshold. It also has very little saturated fat, just 0.3 grams per serving. At 110 calories per 100 grams raw, it’s a high-protein, low-calorie option that works well for people watching their fat intake.
Halibut Still Provides Omega-3s
Being lean doesn’t mean halibut is devoid of omega-3 fatty acids. Pacific halibut delivers about 400 milligrams of combined EPA and DHA per 100 grams. That’s meaningful, though it’s a fraction of what you’d get from salmon or mackerel. Greenland halibut, a fattier relative, provides closer to 900 milligrams per 100 grams.
If you’re eating halibut primarily for omega-3s, you’ll want to eat it more frequently or supplement with fattier fish a couple of times per week. But as a regular part of your diet, halibut still contributes to your overall omega-3 intake.
Where Halibut Really Shines Nutritionally
Halibut’s standout feature isn’t its fat content. It’s a nutrient-dense source of protein and minerals. A cooked half-fillet (about 160 grams) delivers over 100% of your daily selenium needs. Selenium plays a key role in thyroid function and acts as an antioxidant in your cells.
That same serving also covers 57% of your daily niacin, 45% of your phosphorus, 42% of your magnesium, 36% of your vitamin B12, and 32% of your vitamin B6. Few single foods deliver that range of micronutrients in one sitting, and halibut does it at a relatively low calorie cost. With nearly 21 grams of protein per 100 grams, it’s also one of the more protein-rich fish you can buy.
Cooking Tips for Lean Fish
The downside of halibut’s low fat content is that it dries out faster than fattier fish during cooking. Salmon can tolerate a little overcooking because its fat keeps the flesh moist. Halibut doesn’t have that buffer.
Pull halibut off the heat when it reaches an internal temperature of 145°F (63°C). A meat thermometer is the most reliable way to hit that mark. Baking at 375°F for 10 to 15 minutes per inch of thickness is a good baseline. Cooking methods that trap moisture work especially well: parchment paper packets, foil wraps, or a covered baking dish. Adding a drizzle of olive oil or a pat of butter before cooking also compensates for the lean flesh and keeps things tender.
Mercury and Serving Limits
The FDA categorizes halibut as a “Good Choice” rather than a “Best Choice” for mercury levels. This means it contains moderate amounts of mercury, more than low-mercury options like shrimp or tilapia but less than high-mercury fish like swordfish or king mackerel.
For pregnant or breastfeeding individuals, the FDA recommends limiting halibut to one serving per week (about 4 ounces). For the general adult population, halibut a few times per week is considered safe. If you’re eating fish regularly, rotating halibut with lower-mercury options helps keep your overall exposure down.
Halibut vs. Fatty Fish: Which Is Better?
Neither is objectively better. They serve different nutritional roles. If your goal is to maximize omega-3 intake for heart health, fatty fish like salmon or sardines deliver far more per serving. If you want a high-protein, low-calorie fish with an excellent mineral profile, halibut is hard to beat. Many people benefit from eating both: fatty fish for their omega-3 content and lean fish like halibut for variety and micronutrient density without the extra calories.