A calorie ranking only makes sense when the fish are compared in the same state. These values use raw fish per 100 g, without oil, breading or sauce.
Fish at the low-calorie end
| Raw fish | Approx. calories/100 g | Approx. fat |
|---|---|---|
| Flatfish (flounder/sole species) | ~70 | ~1.9 g |
| Haddock | ~74 | ~0.5 g |
| Monkfish | ~75–80 | ~0.7 g |
| Atlantic cod | ~82 | ~0.7 g |
| Hake | ~80–90 | ~1–2 g |
| Pollock | ~90–95 | ~1 g |
The USDA raw flatfish reference provides about 70 calories and 12.4 g protein per 100 g; raw haddock provides about 74 calories and 16.3 g protein.
Fat explains much of the gap
Fat contributes about 9 calories per gram. A fish with 1 g fat receives about 9 calories from fat; one with 12 g receives roughly 108 calories from fat alone. Oily fish therefore tend to be substantially more energy-dense.
Lowest calorie does not mean nutritionally best
Salmon, sardines and mackerel generally contain more calories but also much more EPA and DHA. A cod-versus-salmon choice can depend on whether the priority is low energy density or marine omega-3 intake.
Cooking can reshuffle the numbers
Adding 15 g oil can contribute up to about 135 calories if all of it remains in the food. Even dry cooking concentrates calories per 100 g as water evaporates.
Cooking method can matter more than species
A very lean fish can become a high-calorie dish once it is breaded, deep-fried, or covered with a rich sauce. Fat provides about 9 calories per gram, so oil absorbed during cooking can easily exceed the difference between two naturally lean species. Baking, steaming, poaching, grilling, or air-frying with a measured amount of added fat preserves more of the calorie advantage shown by raw-food comparisons.
Real serving size matters too. A 180-gram fillet provides roughly 1.8 times the calories listed per 100 grams before cooking oil and sides are counted. A smaller portion of a moderately higher-calorie fish may therefore contribute less total energy than a very large portion of the leanest option on a chart.
Many lean fish also provide substantial protein, which makes them useful when someone wants high protein with relatively low energy density. Still, choosing only the lowest-calorie species can crowd out oily fish that supply much more EPA and DHA omega-3. Rotating lean and fatty fish can offer a better balance of energy, micronutrients, and marine fats across the week.
Finally, “white fish” is not a precise nutrition value. Species, season, fat content, and the exact cut create natural variation. When calorie tracking needs to be accurate, use the label on the product or a reliable database entry for that species and preparation rather than assuming every pale fillet has the same composition.
Satiety is not determined by calories per 100 grams alone. Fish provides protein and water, and the fullness of the meal depends on portion, cooking method, and what is served alongside it. A lean fillet with vegetables and a satisfying source of carbohydrate can be a more sustainable meal than simply selecting the lowest number on a chart and then compensating with a large amount of sauce or fried sides.
For people who eat fish frequently, species choice can also involve mercury guidance, sustainability, price, and availability. Those considerations are separate from calorie density but can legitimately outweigh a difference of 10 or 20 calories per 100 grams.
Frozen-fish labels need context as well. A plain fillet, a marinated portion, and a breaded product are not comparable even when the fish species is identical. Added oil, starch, sauce, or sugar can move calories substantially. Use the Nutrition Facts panel for the actual product rather than applying a raw-fish database value to a prepared frozen item.
Water content also explains why cooked values often look higher per 100 grams. As moisture evaporates, protein and calories become concentrated into less weight even when no oil is added. Comparing raw fish with cooked fish on an equal-weight basis can therefore create an apparent calorie increase that partly reflects water loss.
Bottom line
Lean fish commonly sit around 70–95 calories per 100 g raw. Compare species in the same state and account for added fat before deciding which dish is actually lower in calories.
Sources
- USDA FoodData Central — Raw per-100-g composition for flatfish, haddock, cod, pollock and other fish.