When people hear the term "unhealthy fish," they often think of species with high fat content, such as salmon, mackerel, and tuna. However, these species are not inherently unhealthy; they are rich in omega-3 fatty acids, which are crucial for heart, brain, and circulatory health.

These fish are high in calories compared to white fish like cod and hake due to their higher fat content, but this does not make them unhealthy; rather, they are more calorie-dense.

The Most Harmful 3 Fish

The group of fish that experts are particularly concerned about includes predatory species like tuna, swordfish, and shark. These top predators accumulate high levels of mercury and heavy metals in their bodies over their long lifespans.

Sometimes the issue is not the fish itself but the cooking methods used. Deep-fried fish, especially in fast-food settings, loses its nutritional value while absorbing harmful fats and calories.

Fish battered in breadcrumbs and fried, served with fatty sauces, becomes a calorie and fat bomb compared to grilled or baked versions of the same fish.