Mackerel and rainbow trout are both oily fish reached for on omega-3 grounds, though one delivers considerably more of it than the other.
| Nutrient | Mackerel | Rainbow Trout |
|---|---|---|
| Calories | 205 kcal | 141 kcal |
| Protein | 18.6 g | 19.9 g ✓ |
| Total Carbohydrate | 0 g | 0 g |
| Dietary Fiber | 0 g | 0 g |
| Total Sugars | 0 g | 0 g |
| Total Fat | 13.9 g | 6.18 g |
| Saturated Fat | 3.26 g | 1.38 g ✓ |
| Sodium | 90 mg | 51 mg ✓ |
Notable compounds in each
When to choose each
Rainbow trout comes out ahead on the directly comparable numbers here, a touch more protein, less saturated fat, and less sodium, but mackerel’s real selling point doesn’t show up as a “win”: it’s one of the richest oily-fish sources of omega-3 fats available, meaningfully more than trout, which is exactly why mackerel carries more total fat in this table. If omega-3 intake is the priority, mackerel is the stronger choice despite the higher saturated fat and sodium; if you want a leaner fish with a milder flavour, trout has the edge.
Common questions
Is mackerel one of the best sources of omega-3? Yes — mackerel is consistently ranked among the richest dietary sources of omega-3 fats (EPA and DHA), alongside salmon and sardines, which is the main reason it’s recommended so often despite being a fattier fish overall.
Which has less sodium, mackerel or trout? Rainbow trout — around 51mg per 100g versus roughly 90mg for mackerel, though both are low enough that neither is a meaningful sodium concern in a typical diet.
Nutrition values are USDA FoodData Central approximations — see our editorial approach for how we source and verify data.