Cod is one of the healthiest fish you can eat. A 4-ounce serving delivers 20 grams of protein and just 90 calories with half a gram of fat, making it one of the leanest animal proteins available. It’s low in mercury, rich in iodine, and the FDA classifies it as a “Best Choice” fish for everyone, including pregnant women and young children.
Protein and Calories
What makes cod stand out is its protein-to-calorie ratio. At 90 calories and 20 grams of protein per 4-ounce serving, cod is essentially pure lean protein with almost no fat. For context, the same portion of chicken breast has roughly similar protein but more calories. If you’re trying to increase protein intake without adding significant calories or fat to your diet, cod is one of the best options in any grocery store.
Heart Health Benefits
Eating lean white fish like cod appears to directly improve cardiovascular risk markers. A randomized controlled trial found that people who ate lean seafood had lower blood triglyceride levels (a type of fat linked to heart disease) compared to people eating non-seafood protein sources. The lean-seafood group also maintained a healthier ratio of total cholesterol to HDL cholesterol, the ratio cardiologists watch most closely when assessing heart disease risk. The researchers concluded that where your protein comes from, not just how much you eat, meaningfully shapes your cardiovascular risk profile over time.
How Cod Compares on Omega-3s
Cod does contain omega-3 fatty acids, but not nearly as much as fattier fish. Atlantic cod provides about 300 milligrams of EPA and DHA (the two omega-3s your body uses most) per 100 grams. Atlantic farmed salmon, by comparison, delivers about 1,800 milligrams in the same serving. Sockeye salmon provides around 1,200 milligrams.
This doesn’t make cod unhealthy. It just means cod isn’t the fish to rely on if your primary goal is boosting omega-3 intake. Its real strength is as a high-protein, ultra-low-fat food. If you want both benefits, eating cod a few times a week alongside one or two servings of fatty fish like salmon, mackerel, or sardines covers your bases.
Iodine and Thyroid Function
Cod is one of the richest food sources of iodine, a mineral your thyroid gland needs to produce hormones that regulate metabolism, energy, and protein synthesis. Your thyroid concentrates iodine from your bloodstream and uses it to build two key hormones that control metabolic activity throughout your body. Without enough iodine, the thyroid enlarges as it works harder to compensate, a condition known as goiter.
Most people in developed countries get adequate iodine from iodized salt, but if you cook with sea salt or kosher salt (which typically aren’t iodized), eating cod regularly helps fill that gap naturally.
Mercury and Safety
Cod is a low-mercury fish. FDA testing found an average mercury concentration of 0.111 parts per million, which is well below the levels found in higher-risk fish like swordfish, shark, or king mackerel. That low mercury level is why the FDA places cod in its “Best Choice” category.
For pregnant or breastfeeding women, the FDA recommends 2 to 3 servings per week from the “Best Choice” list, with one serving being about 4 ounces (roughly the size of your palm). Children can safely eat 2 servings per week, with portion sizes scaling by age: about 1 ounce for toddlers, 2 ounces for ages 4 to 7, and working up to 4 ounces by age 11.
Baked vs. Fried Cod
How you cook cod matters almost as much as choosing to eat it. Baked or broiled cod retains its nutritional profile: low calorie, low fat, high protein. Deep-fried cod, the kind you get at a fish fry, adds significant calories, total fat, saturated fat, and sodium from the batter and frying oil. The fish itself is still nutritious underneath, but the breading and frying process can easily double or triple the calorie count of a serving.
Even baking has pitfalls if you’re not paying attention. Every pat of salted butter you add contributes 36 calories, 4 grams of fat, and 32 milligrams of sodium. Lemon juice, herbs, and a light drizzle of olive oil keep the dish lean without sacrificing flavor.
Sustainability Considerations
Cod has a complicated environmental history. North Atlantic cod stocks famously collapsed in the early 1990s due to overfishing, and recovery has been uneven. A 2016 analysis of fish stocks certified by the Marine Stewardship Council (MSC) in the Northeast Atlantic found that even among certified fisheries, 44% of stocks were still being fished above sustainable levels in their last assessed year. In some cases, fishing quotas were set 20 to 60 percent above what was actually being caught, while in others, actual landings exceeded quotas by 30 to 50 percent.
If sustainability matters to you, look for Pacific cod (sometimes labeled as Alaska cod), which generally has healthier stock levels. Checking for country of origin and how the fish was caught (hook-and-line tends to be less destructive than bottom trawling) gives you more information than a certification label alone.