Fish is considered the pinnacle of health foods mostly due to its rich omega-3 fatty acids, but not all fish are nutritiously created equal. Salmon has been touted for its hearty-healthy omega-3 benefits and monosaturated fat, but research suggests the “couch potato” of fish is undeserving of its label as a “lean and healthy food.” According to an analysis by the Sunday Times, some varieties of farmed smoked salmon may contain up to twice as much fat than a margherita pizza and three times as much fat as the wild caught equivalent.

Although the omega-3 fatty acids in fish are beneficial, the U.S. Department of Agriculture (USDA) has found fat in smoked fish contains a lower content of these healthy fats than its wild fish counterpart. "The farmed salmon is a couch potato compared to the majestic and iconic wild salmon,” Don Staniford, director of the Global Alliance against Industrial Aquaculture, told the Sunday Times. "It is complete nonsense to describe this flabby farmed fish as lean and healthy."

The Sunday Times investigation put into question the marketing of smoked salmon as a healthy oily fish. The analysis found a classic Pizza Express margherita contains 6.4 grams (g) of fat per 100g while Sainsbury’s Scottish oak smoked salmon made from farmed fish contains 14g of fat per 100g, compared to Sainsbury’s wild Alaskan smoked salmon contains 3.2g of fat per 100g. Tesco’s farmed smoked salmon contains three times as much fat as the wild alternative with 9.9g of fat per 100g compared to 3.3g of fat. In Waitrose, the Heston Blumenthal lapsang souchong tea smoked salmon contains 10.5g of fat per 100g, while its wild counterpart, Alaskan whisky oak smoked salmon, contains just 2.7g per 100g.

The discrepancy in fat content between wild and farmed salmon has to do with their environment. Unlike other fish stocks, farmed smoked salmon is usually confined in small areas where the fish cannot swim freely and tend to put on weight. Unlike its smoked counterpart, wild smoked salmon swim hundreds of miles, and therefore contain a third of the fat per 100g. This is why many companies, like Salisbury’s, treat them as two different kinds of fish, the Daily Mail reported.

Smoked salmon contains insidious amounts of sodium; just an ounce contains 222 milligrams, while a lox, the belly portion of salmon, has 567 milligrams per ounce, according to USDA data. This amount of sodium could counterbalance the benefits of omega-3 fats. In addition, farmed smoked salmon contains critical chemicals like polycyclic aromatic hydrocarbons and pathological bacteria, which can lead to cancer and increase risk of fatal infections.

In this food war, neither farmed smoked salmon nor pizza is good for you, so instead opt for the wild caught variety.