Which is more nutritious, autumn salmon or mackerel?

Autumn salmon is richer in protein and vitamin D, while mackerel is higher in fat and calories. Both are excellent sources of protein and healthy fats like EPA and DHA. Autumn salmon contains more protein (22.3g per 100g) and vitamin D, with lower fat (4.1g) and calories (124kcal). Mackerel has less protein (20.6g) but significantly more fat (16.8g) and calories (211kcal). Salmon also contains astaxanthin, an antioxidant beneficial for skin health and disease prevention. Salmon's fat-soluble nutrients are better absorbed when cooked with fats like butter.