Smoked salmon made from fish farmed in Scotland contains more fat than a pizza, an investigation has found.
The farmed version of smoked salmon products also contain at least three times as much fat as the wild equivalent.
Salmon is marketed as a healthy oily fish that contains omega 3 fatty acids which are good for health.
Oily fish should be eaten at least once a week under healthy eating recommendations.
However campaigners have called farmed salmon the 'couch potato' of fish because it is grown in a confined space and does not swim the same distances as the leaner, less fatty wild fish.
An analysis by the Sunday Times found a classic Pizza Express margherita contains 6.4g of fat per 100g while Sainsbury's Scottish oak smoked salmon made from farmed fish contains 14g of fat per 100g.
The wild equivalent, 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 with 3.3g of fat, the newspaper found
In Waitrose, the Heston Blumenthal lapsang souchong tea smoked salmon contains 10.5g of fat per 100g while the wild Alaskan whisky oak smoked salmon contains just 2.7g per 100g.
Don Staniford, director of the Global Alliance against Industrial Aquaculture, told the Sunday Times: "The farmed salmon is a couch potato compared to the majestic and iconic wild salmon."
"It is complete nonsense to describe this flabby farmed fish as lean and healthy."
Waitrose said it would change the use of the word "lean" on the lapsang souchong tea smoked salmon.
A spokesman said: "We are very sorry for this oversight, which we are correcting immediately."
A Sainsbury's spokesman said that it always clearly marked smoked salmon as wild or farmed and pointed out that they are different species of salmon, so "looking at the fat content between the two is not comparing like for like".
Tesco told the Sunday Times its farmed smoked salmon products were clearly labelled and included the location of the farm.
The omega-3 fatty acids in fish are beneficial but United States Department of Agriculture data has shown that the fat in farmed salmon contains a smaller proportion of omega-3 fatty acids than in the wild fish.
The farmed salmon is, however, likely to contain more omega-3 overall because of the higher levels of fat.