Publication last week of a ‘Fat Map’ showing the growing obesity hot-spots in Britain has once again sparked debate about the degree to which politicians should interfere in our lives for our own good. The Tories, predictably, are insisting that people should take responsibility for what they eat: ‘No Nannying, No Excuses’, as shadow health secretary Andrew Lansley put it charmingly last week. Meanwhile, the government is pressing for a more hands-on approach to tackling obesity, probably because it has finally realised that Fat is a Fiscal issue.

The government’s position is derived from its own Foresight report, published last year, which explained why obesity is a societal, rather than an individual, problem. The report argued that, thanks to ‘technological revolution…outstripping human evolution’, Britain has evolved into an ‘obesogenic environment’ in which, for an increasing number of people, ‘weight gain is the inevitable – and largely involuntary – consequence of exposure to a modern lifestyle’. Far from being something people can discipline themselves out of, obesity results from a complex range of causes that include ‘physiological factors, eating habits, activity levels and psychosocial influences’. Obesity, in other words, has become passive: the quasi-inevitable consequence of merely existing.

No-one disputes that computers, cars, burgers and bars are having a devastating cumulative effect on the nation’s waistline, yet last week’s Fat Map demonstrates something rather more disturbing. Indeed, the mere fact of its being a map is the key to its message. While communities as diverse at the Shetland Isles, rural Wales, the North East, Isle of Wight and Dagenham ponder why they have come out top of the tubby tables, the conclusion that where you live is directly related to how fat you are likely to become – and therefore how healthy, hearty and happy – is hard to ignore.

What the Fat Map shows, in essence, is those parts of the country where one is most likely to be born into relative deprivation – where the deadly hand of ‘passive obesity’ is most likely to strike. Like Charles Booth’s London Poverty Map of 1889, it charts far more than it says on the label. The Fat Map, in effect, is a Poverty Map by another name, which is why it is so politically explosive.

The health secretary Alan Johnson is right to say that ‘vilifying the extremely fat doesn’t make people change their behaviour’, and equally correct that, in order to tackle obesity, we are going to need ‘a fundamental change in the way we live our lives’. But how are we going to do that, exactly?

Obesity is not just a question of what we eat – it is the bodily manifestation of society itself – or rather, of our place in it. Those who are well educated, who can afford to buy healthy food, who have the leisure to play sports, to shop and cook for fun, suffer from it far less. The fundamental change we need is to extend those rights to everyone – which should, after all, be the core aim of socialism. Job opportunities, good schools, safe places to play, easy access to fresh food, communal sports facilities, well-designed and maintained neighbourhoods, are what is needed. That is why obesity lies within the remit of government – and of architects and urban designers, for that matter. Obesity is not a matter of individual choice. It’s the environment, stupid.

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