Does a 200-gram serve of salmon have more fat than a Big Mac and fries?

^{By Lulu Graham and David Campbell}

An online video narrated by British-Australian actor Miriam Margolyes has accused the Tasmanian salmon industry of selling a product that is unhealthier than customers realise.

The video, produced by environmental lobby group Neighbours of Fish Farming (NOFF) and titled "The toxic truth", claims: “A 200-gram piece of this [Tasmanian Atlantic] salmon has more fat than a Big Mac and fries.” 

The short film has been viewed thousands of times since being published to Facebook and Vimeo in May 2022.

But these numbers are problematic when viewed in isolation, not least because nutritional experts said that, compared to the burger and fries, salmon contains more fats considered to be healthy.

A spokesman for NOFF supplied RMIT FactLab with the results of testing it commissioned in 2021, which he said were the basis for the group's claim. These figures were subsequently published on their website.

The analysis was conducted by Eurofins, a laboratory services provider accredited by the National Association of Testing Authorities that offers "testing services for nutrition information panels, label claims and other analyses in food". 

It tested two fillets each from Tasmania's three major salmon producers: Tassal, Huon Aquaculture and Petuna Seafoods.  

Experts told FactLab they had no issue with the approach taken by the lab, with Giovanni Turchini, the head of Melbourne University's School of Agriculture, Food and Ecosystems Sciences, adding that six samples were "more than sufficient" for the comparison.

The experts also recommended comparing the results on the basis of fat per 100 grams of each food. Nicole Kellow, a senior research fellow with Monash University's Department of Nutrition, Dietetics and Food, said this was "the only way we can compare nutritional content between two different foods".

The video included separate claims about farmed salmon containing higher levels of harmful trans and saturated fats compared with wild-caught salmon, which are beyond the scope of this fact check.

However, their inclusion immediately before the claim about "more fat" may lead viewers to believe these levels were also higher in salmon than in a Big Mac and fries.

What the testing found

The test results showed that, per 100 grams, Tassal's salmon fillet samples contained 21.2–28.5 grams of total fat, Huon's 23.7–24.2 grams and Petuna's 16.3–19.8 grams.

This means all six fillets had more total fat per 100 grams than the burger and fries (13.6–13.8 grams). They also had more total fat on average (22.3 grams).

McDonald's Australia does not publish figures on its website relating to trans fats.

When it came to saturated fat, three of the six salmon fillets had at least as much per 100 grams as any size of McDonald's Big Mac and fries combo.

On average, the salmon had the same amount of saturated fat per 100 grams as a small combo (4.2 grams). It had slightly less than a burger on its own (5 grams).

Product information published by Tassal claims that its salmon is leaner than what the testing showed, with 16.1 grams of total fat and 3.1 grams of saturated fat. (Petuna and Huon do not publish nutritional information on their websites.)

Dr Keller told FactLab that, from her experience, "there's always quite a bit of difference in what they say on the label" and what independent tests show.

In the case of farmed salmon, she pointed to a number of studies showing that the fish's fat levels can be influenced by factors such as the time of year. 

A spokesperson for the Tasmanian Salmonid Growers Association, an industry body representing all three companies, has previously dismissed the test results, telling the Guardian they would be skewed by seasonal variations and arguing that the companies' nutrition labels reflected data collected over three years.

What about a '200-gram piece'?

Notably, the video compared a burger and fries with a 200-gram portion of salmon, though Tassal's and Huon's catalogues suggest this would be a particularly large serving.

While 200-gram fillets are available, most pre-packaged salmon fillets sold by the major supermarkets range between 115 and 150 grams each (for example, here, here, here and here).

Australia's dietary guidelines state that a standard serve of fish fillet is 115 grams, and according to NOFF, the pieces it tested ranged between 100 and 130 grams.

Issues aside, extrapolating the average test result (per 100 grams) would mean a 200-gram fillet had 44.6 grams of total fat, which is slightly more than the combined total fat content of a Big Mac and small fries (41.7 grams).

But the story changes if the fries were either medium (46.3 grams) or large (49.8 grams) or if the salmon fillet was a slightly smaller 185 grams (41.2 grams of fat) – and under every scenario, the salmon contained less saturated fat.

What the experts say

Critically, experts dismissed the simplistic comparison of total fat present in the two foods because it ignored the differences between different types of fats.

Dr Kellow said salmon had high levels of omega-3 and other polyunsaturated fats while containing "low levels of saturated and trans fatty acids".

"So, the salmon, although it's high in fat, it's the type of fat that you actually want in your diet that is actually associated with low cardiovascular risk," she said. 

"You can have a high total fat diet, but if it's mainly mono- and polyunsaturated fats, then there's no adverse health effects of having a high fat diet."

Professor Turchini said it was "nutritionally meaningless" to compare total fat because "the quality of the fat is pivotal, not the quantity".

He argued similarly that the McDonald's burger was relatively high in “bad” fats while fish was relatively high in "very health-promoting" ones.

Professor Turchini also described the focus on fat alone as “silly”, noting it could equally be argued that “a bowl … of steamed broccoli has massively more fat, as well as more saturated fat, than a bowl … of sugar".

_{— Editor's note: This article has been amended to remove reference to a third party previously named; to make clear that salmon is higher in healthy fats relative to a burger and fries; and to correct an error in how the figures per 100 gram were calculated for the McDonald's combo meals. It does not change our verdict.}