William Skidelsky finds fast needn't be bad

In my view, eating is a bit like sex: there aren't enough ways you can do it

When my girlfriend and I went on one of our first-ever dates, we found ourselves passing a café-type establishment in London's Chinatown, the kind of place that serves dodgy-looking, brightly coloured dishes from a steel counter near the front. We were both hungry, and the film we were planning to watch was due to start in 15 minutes. The cinema was ten minutes away. "Let's go in here, get a takeaway, and eat it on the way," I suggested. She looked appalled. "I wasn't brought up to eat on the street," she said. And so we sat at one of the café's plastic tables, ate our meal in double-quick time, and ended up missing the first five minutes of Super Size Me.

If, in the intervening two years, my girlfriend has relented a bit from this stance - if she occasionally deigns to take a bite from my croissant on the way to the Tube in the morning - then I consider this to be a triumph of sorts. I am, you see, a believer in eating on the move. I don't agree with the view that there are situations in which consuming food is improper; that, if done too openly, in full view of others, it could be shameful. In my view, eating is like sex: there aren't enough ways you can do it. There is slow and adoring (the three-star treatment); quick and furtive (greasy spoon); out in the open (sandwich from deli). Well, perhaps I don't really mean the last part of that analogy - but you get the gist.

I was reminded of all this while reading Kevin Jackson's excellent book Fast: feasting on the streets of London (Portobello Books, £9.99), an account of a "meander" through the capital in order to "winkle out something of what it all looks and feels . . . like to eat on the hoof on the streets of London". Jackson, who is a learned and entertaining guide, reminds us that the term "fast food" has been debased by its association with "globalism and US imperialism" - in short, with McDonald's. He wants to remind us of what fast food was once all about: "countless small-scale institutions which sprang up across the centuries" to serve a "ragged army of citizens without a kitchen".

In fact, London - and Britain's other big cities - do not lack for decent fast-food joints. There are fish-and-chip shops, kebab shops, pizza parlours, vegetarian cafés. And there's the latest fashion - unremarked on by Jackson - for "gastro" fast food. What we lack is any real sense of a street-food culture. Fast food is best when purchased not from a shop, but from a stall. That way, you don't have any choice but to eat standing up, and probably with your hands. I'd love to live in the kind of city where you can't walk for five minutes without being assailed by the sight and smell of things being cooked. London, I suspect, was a bit like this once. Perhaps it will be again, one day.