Nope, 'food porn' isn't making us fat.

Some 'food porn' what I made

Salivate, dear reader. Salivate. Look at the oil, the cheese. Imagine the flavours as they explode in you mouth, savour the thought of that yolk as it bursts open running down onto the plate. You're hungry now aren't you?

The argument is that, when we see an attractive image of food, blood rushes to the parts of our brain associated with taste. We experience the desire to eat, even if we’re not hungry. According to one of the authors of the review, Professor Charles Spence of Oxford University, this has been measured in brain scans.

“The taste cortex lights up,” he says. “There’s an increase in blood-flow and, depending on the state of the person, or how realistic the image is, it might be triggering restraint mechanisms. You’re seeing it and thinking: ‘I shouldn’t be eating that.’

Apparently the proliferation of food images - each one lighting up the 'taste cortex' - is one of the things making us fat. Or so says Dr Spence:

“What we’re trying to say in this paper is that there are consequences from food porn. It’s a term that hints at the way that it depletes our resources of self-restraint. When we sit down for a meal at home after watching a cookery programme maybe we eat more than we would otherwise have done.”

And so on in this vein culminating in an orgasm of nannying fussbucketry:

Should we be protected, then, from over-exposure to “food porn”? “Should OFM, Delicious and all those food magazines be moved to the top shelf? I don’t think it’ll go that far,” he says, “but I do think government agencies should think seriously about our exposure to visual food cues."

The problem here is that while it seems entirely reasonable for our brains to light up at 'food porn', Dr Spence and his colleagues really don't show any direct link between "eating with our eyes" and obesity. Here from the conclusions to the original article in Brain and Cognition:

Crucially, the question that has yet to receive a satisfactory answer is just what the impact of all those appealing food images is having on the consumption behaviour of those in the Western world who are both flooded with opportunities to eat, and at the same time bombarded with gastroporn.

So all that research hasn't answered the question? Probably because there isn't much of a link. It seems reasonable to use tests of links between food advertising and obesity as a proxy for what Dr Spence and his colleagues are saying:

Based on a reading of the literature, it appears clear that there is no evidence for a direct causal relationship between food advertising and obesity levels.

or:

Despite media claims to the contrary, there is no good evidence that advertising has a substantial influence on children's food consumption and, consequently, no reason to believe that a complete ban on advertising would have any useful impact on childhood obesity rates. Again, Hastings et al. appear to concur with this judgment: 'there is no prima facie reason to assume that promotion will undermine children's dietary health; it can influence it, but this influence could just as easily be positive as negative.'

It's true that there's also a great deal of research that sort of says "children watch more TV food advertising, children are fatter, therefore food advertising is causing obesity". Some of this research has very precise numbers as to the amount of obesity that banning food advertising would prevent even though each time it fails to demonstrate any actual link between the pictures of food and the fat children.

This whole idea - sometimes (and unattractively) called the 'obesogenic environment' - is very convenient if you are an adherent of the church of public health or an enthusiastic nannying fussbucket. This is because is suggests that fatties aren't to blame for their fatness but are victims of wicked advertisers, manufacturers and retailers with their cunning marketing tricks. So instead of sending a message to the obese that perhaps it might be a good idea for them to eat less and move more (and maybe even helping them do this), we send them a message that the reason they're fat is the food industry and its agents in advertising or retailing. Unsurprisingly that message works all too well with calls for bans matched only by an ever more intense panic about an epidemic of obesity.

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