A few years ago, when Transition Town Lewes was just starting up, I had tea with a local historian, Colin Brent. Colin told me that, in Victorian times, almost everything was owned by, and for, Lewes people. As well as the printing presses, bus companies, prisons and cobblers, virtually all the food eaten in Lewes was grown locally.

Documents from that time show that, with a population half the current size, we had fifteen bakers, twenty butchers, a couple of dozen greengrocers and a plethora of corner shops. Far from the meagre diet we imagine, photographs show an abundance of fresh food in season. The fields were well cultivated with a wide range of local grains and vegetables, and the weekly markets and even back gardens heaved with livestock and weekly markets, while fish were brought up from the fishing boats at Newhaven.

Such a rich food economy meant that many people made a living from food, from the farmers, butchers, millers, shopkeepers, cheese makers, delivery boys and brewers (20 in Lewes alone!).

I’m not saying that life was necessarily easy, just that it was based on a complex web of relationships between people and the land they inhabited locally.

A century on, and all that web has gone. Today, in Lewes, we spend about fifty million pounds a year on food and drink and most of that – at least forty million – is spent in our three supermarkets: Tesco, Waitrose and Aldi. In those hundred years – and especially the last fifty years since I was born – we’ve managed to let all this natural capital be diverted into the hands of a few multinational corporations. Our local food economies have dried up; local money no longer circulates around and about the town, building wealth and relationships as it goes. A tenner spent locally multiplies many times over as it circulates. Spent in a supermarket, that tenner goes straight out of town and into the hands of Tesco and co, and its shareholders.

As a direct result, the local economy in Lewes is struggling. There are no more bakers in Lewes. We have one greengrocer, at the top of town where the rents are affordable, and only two butchers are left. Just in the last five years, according to the new economics foundation, Lewes has gone from being a ‘home town’ with a wide mix of independent shops supporting a strong local economy, to a borderline clone town. The independent shops we once were so proud of are now either chains or strange chi-chi shops selling expensive string, as the joke goes round here.

My sense is that most people don’t realise, or don’t want to realise, that shopping in their local supermarket could wreak such havoc on their community. They would rather believe it’s more convenient, and cheaper. But that’s just one of the myths perpetuated by supermarkets in their relentless marketing. While individual items are often cheaper in supermarkets than in local shops, once you add in to the shopping basket the convenience food, comfort food and other items we think we need – including cleaning and beauty products – you end up spending far more in supermarkets than elsewhere. I was shocked recently to discover that the average weekly supermarket spend is about £60 a head; I spend half that shopping locally, and we eat only organically.

Additionally, those people who don’t much like shopping can design easy ways of avoiding the supermarkets, thus busting the convenience myth. For instance, in our household, we get wholefoods and minimal toiletries delivered in bulk four times a year, then either buy the fresh stuff in the weekly market, or grow it. Simple!

It’s hard to imagine how we can stop supermarkets becoming ever more powerful. A couple of years ago my friend Marina and I tried to prevent our local Tesco from expanding by 50% in size. Despite our planning committee’s desire to block the expansion, knowing well that such a move would kill off more local shops, despite a petition of 1,000 people, and several days sifting through papers in the planning department, the committee gave in to Tesco, probably clearly realising it would never be able to stand up against Tesco’s lawyers. Supermarkets up and down the country simply landbank when faced with opposition, only to wear down their opponents with fresh waves of documented arguments. Our planning laws, concluded government advisor Mary Portas recently, are simply unable to protect our high streets from such opportunism.

My biggest gripe about supermarkets is that they monetarise our natural resources and externalise the problems caused by that act. Corporations by their nature seek to maximise profits above all other concerns, even Waitrose, who just make it seem cleaner. That’s their job. They seek to extract as much of our commons as they can get away with – undermining healthy soil with chemical farming methods; eroding the biodiversity that allows our honeybees to live in good health to pollinate our food; blasting our quiet countryside with their noisy machines. We can no longer bank on a healthy gene pool for our vegetables, fresh river water and full aquifers, or even fresh air for our children to breathe. To add insult, we even have to pay for that loss of health and wellbeing through our taxes. It’s a complex argument made beautifully in an extraordinary new book called Sacred Economics by American philosopher Charles Eisenstein.

Due to this outrageous lack of caretaking by these corporations – our politicians standing by, impotently – a food crisis seems both inevitable and imminent. At the same time, there are some small, glimmering signs that we are slowly coming to our senses. Food projects are springing up all over the country, often in transition towns. Here in Transition Town Lewes, we started a food market nearly two years ago, with the help of the District Council. Our weekly market now has 20 regular stallholders, each of them earning a modest living; some of them only exist because of the market.

And alongside the ‘parallel public infrastructure’ that transition towns do so well, there are a growing number of people who are just leaving supermarkets behind. I’m in my sixth month of not walking into a supermarket and I’m not alone – a recent survey in Transition Town Lewes shows a number of others doing the same.

Some people say that as fossil fuels become more expensive, the globalised food system will less affordable, and localisation of food inevitable. In the meantime, we each have it in our power to hasten the demise of the supermarkets; we have created them through consumer choice, and we can all of us, one meal at a time – simply and joyfully – choose to eat differently!

 Lewes food shops, 100 years ago by kind permission of Sussex Archeological Society and Dr Colin Brent