What do cooking methods such as baking, grilling, and poaching aim to achieve when preparing oily fish?

To retain healthy fats while avoiding the addition of unhealthy ones.

The preparation technique significantly affects whether the inherent health benefits of oily fish are retained or compromised. Methods like baking, grilling, poaching, and steaming are favored because they are dry or moist heat methods that generally require very little, if any, added cooking fat. This approach successfully preserves the beneficial long-chain omega-3 fats that are already present in the fish tissue. In contrast, methods involving excessive added fat, such as deep-frying, introduce unnecessary calories and undesirable fats, actively working against the intended nutritional advantages of consuming the fish.