A cooked 100 gram serving of freshwater bass provides roughly 124 calories and over 23 grams of protein with very little fat, making it a genuinely lean, high-protein food. The bigger consideration for most people is not the nutrition profile itself but mercury, which builds up in largemouth bass more than in smaller, lower-food-chain fish.
Nutrition Snapshot (100g, cooked)
What Are the Actual Nutrition Facts for Largemouth Bass?
Based on USDA nutrient data for freshwater bass, the closest official category to largemouth bass specifically, a cooked 100 gram (roughly 3.5 ounce) portion provides approximately 124 calories, 23 to 24 grams of protein, and around 2.5 to 4.5 grams of fat, with essentially no carbohydrates. That profile makes it a lean, high-protein fish broadly comparable to other popular white-flesh freshwater species like walleye and crappie, well below fattier fish like salmon in total fat and calories but also lower in the omega-3 fatty acids that fattier fish provide in larger amounts. Bass also contributes meaningful amounts of several micronutrients typical of fish generally, including vitamin D, calcium, and iron, though it is not an exceptional source of any single nutrient compared to other lean fish.
| Fish | Calories | Protein | Fat |
|---|---|---|---|
| Largemouth / freshwater bass | ~124 kcal | ~23-24g | ~2.5-4.5g |
| Walleye | ~93 kcal | ~21g | ~1g |
| Salmon (Atlantic, farmed) | ~206 kcal | ~22g | ~13g |
How Much Mercury Does Largemouth Bass Contain?
Largemouth bass mercury levels vary considerably by water body and fish size, but EPA survey data puts typical mean concentrations for largemouth and smallmouth bass in the range of roughly 0.2 to 0.7 parts per million, with some regional studies reporting means around 0.27 to 0.70 ppm across different lake and river systems. For comparison, the EPA’s fish tissue criterion, the methylmercury concentration considered safe based on eating about two 8-ounce meals per month, sits at 0.3 ppm. That means a meaningful share of largemouth bass, especially larger, older individuals from contaminated or naturally mercury-rich waters, test above the EPA’s general guidance level, which is exactly why state consumption advisories exist and why they vary so much from one water body to the next rather than applying a single nationwide rule.
Why Does Fish Size Matter So Much for Mercury Content?
Mercury bioaccumulates, meaning it builds up in a fish’s tissue over its lifetime rather than being processed and eliminated, and largemouth bass mercury concentration correlates strongly with body weight in research on the species. A predatory fish that has spent a decade or more eating other fish has had far more time to accumulate mercury than a young, fast-growing fish only a year or two old, which is the biological basis behind the common advice to release larger, older bass rather than keep them for the table. This size effect is a major reason many state advisories set different consumption limits, or none at all, based on fish length rather than treating every largemouth bass caught from a given water as equally safe to eat.
Who Should Be Most Careful About Mercury in Largemouth Bass?
Pregnant women, women who may become pregnant, nursing mothers, and young children face the greatest risk from methylmercury exposure, since it can affect a developing nervous system more seriously than it affects a healthy adult. State advisories commonly recommend these groups avoid largemouth bass entirely from waters with elevated mercury readings, or limit consumption to a single small meal per month at most, while general adult guidance is typically more permissive, often allowing one to two meals per month depending on the specific water body’s advisory level. Checking the specific advisory for the water a fish was caught from, rather than relying on a general species-wide rule, remains the most reliable way to manage this risk.
Frequently Asked Questions
Is largemouth bass a healthy fish to eat?
Nutritionally, yes. It is a lean, high-protein food low in fat and carbohydrates. The main health consideration is mercury, which builds up more in bass than in smaller, lower-food-chain fish, so moderation and checking local advisories matter.
How much mercury is in largemouth bass?
Typical mean concentrations fall around 0.2 to 0.7 ppm, though this varies significantly by water body and fish size, with some larger fish from contaminated waters testing well above the EPA’s 0.3 ppm general guidance level.
Does a bigger largemouth bass have more mercury than a smaller one?
Yes. Mercury accumulates in a fish’s tissue over its lifetime, and research shows a strong correlation between largemouth bass body weight and mercury concentration, which is why larger, older fish are generally the ones advisories recommend limiting most.
Should pregnant women eat largemouth bass?
Many state advisories recommend pregnant women, nursing mothers, and young children avoid largemouth bass from waters with elevated mercury, or limit it to a single small meal per month at most. Always check the specific advisory for the water the fish was caught from.