Undeniably, there is a problem with the way women are presented in media and advertising with regards to weight: models are skinnier than most of us are – some of them unhealthily so. Promoting a wide range of body-types in the media is an unequivocally ‘good thing’. But is it being taken to an extreme at one end of the scale?

Fat: in the last few years it has emerged as a rights movement, an industry, a politics, a sexuality and even a subculture. But how far can Fativism be taken before having to acknowledge that there’s an elephant in the room: the undeniable level of associated medical risk?

There is something extremely valuable in a movement which works against the ridicule and harassment of overweight people, and making sure that anti-obesity campaigns don’t target and marginalise the people they aim to help, as well as looking at the root of this problem in economics and the failures of health education.

But can, or should, this pendulum swing all the way to outright celebration?

There are intriguing theories which look at society’s fear of fat as a fear of deviance, theories which see ridicule and marginalisation as a means of social control, and see fat as a self-conscious and brave rejection of society’s aesthetic and sexual norms. There is a particularly interesting set of ideas regarding the intersection of fat and feminism as political issues. These are compelling on a theoretical level, but the reality is that the majority of people did not become fat as a political statement, neither does remaining fat have anything to do with politics.

At the National Portrait Gallery this month, in amongst the old oil portraits of Britain’s historical great and good, are new portraits by Grayson Perry exploring new modes of ‘British’ identity’. Among them is a set of statues of three contestants from the Miss Plus Size International pageant, through which Perry explores this group and the contradictions embodied in their pride and promotion of their body-type.

In the segment of Perry’s related documentary series ‘Who Are You?’ in which he meets and speaks to a group of these women, there is a really touching sense of community and confidence which the women get from each other – and the problems they face are undeniably difficult and real.

‘F*ck Skinny Bitches’ (Guru Minaj) – but isn’t there a difference between natural curves and a clinical excess of weight? Regardless of pressures about size, and sexiness, and the cloud of nebulous arguments regarding identity there is an absolute which threatens the pride these women exhibit, one which medical evidence makes difficult to deny.

Perry’s own comparison of the struggle of ‘plus size’ from marginalisation to accepted facet of mainstream to that of homosexuality, seems misguided and brings up its own set of difficulties about the plus size industry (consisting of events, clothing, pageantry and more), which seems to celebrate its own success, with a growing customer base every year, as a measure of its conceptual validity, rather than of a growing obesity issue in the UK.

It’s hard to reconcile the idea of pride in a group identity with a group whose very unifying factor puts so much strain on themselves, and the NHS – costing £5bn per year, (more than smoking according to some estimates). I struggle to imagine a smokers’ pageant – Miss Ashtray International? Dr Peter Mace, assistant medical director of Bupa, suggests that this normalisation might even cause a complacency about medical risks relating to obesity: ‘People often don’t think of themselves as heavy because they are the same size as everyone around them – but the health risks are the same, and very serious’.

Perry’s statues, which stand proud and impressive, wear dresses which are plastered with images of media presentations of conventionally attractive women, and, layered over and amongst them, images of food like doughnuts and sweets. This incongruity seems to encapsulate the contradiction in the statement the women were making about themselves: the identity they claimed was one they themselves had (to some degree) chosen.

It isn’t that you can’t be fat and beautiful, fat and sexual, fat and intelligent, fat and whatever else – it isn’t about setting fat up in binary opposition to anything apart from fit. Because it is, inherently, the opposite of fit. And to ignore that fact would be negligent on both a personal and global scale, whatever  the other benefits are to integrating the presentation of larger body shapes into mainstream media.

As ever, media responsibility will be at the crux: presenting the big picture, as well as the small, and the curvy, and the muscular, and, with care, the fat.