You have to go back to 1816 to find a serious British food riot, the year after an Indonesian volcano erupted cancelling summer and blighting the global crop. Today, food riots are what happen in Thailand, Mexico or, as we reported last week, Mozambique, where seven people died in protests over a 30% hike in the price of bread. The question is whether the circumstances which led to that murderous bout of civil unrest have any implications for Britain. Too often, we regard ourselves as mere observers and commentators rather than potential participants in the dramas surrounding the complexities of food security. Until a few years ago, this was British government policy. A Cabinet Office document, nicknamed by Tim Lang, professor of food policy at City University, the "leave it to Tesco report", argued that we are a rich developed nation which could buy its way out of any supply crisis on the global market.

But with Russia banning wheat exports until the end of 2011, commodity prices lurching upwards and the United Nation's Food and Agriculture Organisation preparing for an emergency meeting to discuss the crisis, that position looks hopelessly naive. Having spent the past month travelling across Britain investigating the sustainability of our food supply for a new TV show, it's clear to me that we risk replacing a culture of a cheap and plentiful present with one of hyper-expense and scarcity in just a few years' time.

We need to look seriously at how we produce our food and how we eat it. Our self-sufficiency has dropped in the past decade from north of 70% to around 60%, according to official figures. Many experts think it may actually be nearer to just 50%. We import 60% of our vegetables. If this drift continues, we will be left exposed to the sort of events that triggered the riots in Africa. We need to make difficult decisions which a lot of people who regard themselves as serious foodies may find deeply unappetising. And we need to make them fast.

Any consumer of gastroporn in print, online and on our TV screens would imagine we were already having this debate. Words such as local, seasonal and organic have become a holy trinity. But these are merely lifestyle choices for the affluent middle-classes, a matter of aesthetics, and nothing to do with the real issues. Start in the fruit aisle of your supermarket. The major supermarkets are not inherently evil. On balance, they probably help our lives more than they hinder them, but they only respond to consumer demand and what the consumer demands is not always right.

Look at the bags of perfect fruit, shiny, unblemished, the supermodels of the apple world. They only look like that because of the grading out of fruit which, while perfectly edible, is not comely enough for harried shoppers. In Kent recently, I met David Deme, for decades an apple farmer, who a few years ago decided he had to stop supplying supermarkets because he was being forced to "grade out" 30% to 40% of his fruit. He found this unacceptable and chose to move into a premium market, by making apple juice. Other English apple growers have similar stories to tell.

Which goes some way to explaining why Britain, a country perfectly suited to growing apples, now imports 70% of those we eat. The apple shelves are a global tour, from Chile to South Africa, from New Zealand to China, even as we head into prime British apple season. We will never become self-sufficient in apples, but it is possible to reverse the numbers so that only 30% come from abroad, if we stop being obsessed over the look of the fruit and are prepared to pay more for what we buy, so that fruit farmers could invest in new varieties and the best storage techniques.

Cost is key. In the early 90s, we spent roughly 20% of our wages on our shopping bill. Today, it's nearer 10%, even allowing for recent inflation, and we assume these low prices to be a right. The result is margins for our farmers that are so tight many are giving up. Nowhere is this more obvious than in the dairy industry which is not only shedding farmers every week, but losing its future workforce too, as the traditions of family succession dwindle. Farmers' kids don't want to go into the business and their parents don't want them too, either. A country suited to dairy farming is no longer self-sufficient in milk. We're importing the stuff.

The solution, embracing of the kind of super dairy proposed at Nocton Heath in Lincolnshire, which will house more than 8,000 cows, bedded down indoors on sand, is met with howls of derision because it's not "natural". The dairy farmers I've talked to may take issue with it for the impact it could have on smaller farms, but none of them sees animal welfare as an issue. Unhappy, ill animals do not produce milk, so it's not in the farm's interests to mistreat them or shorten their lifespan. Also, the carbon footprint of such a large facility may actually be many times smaller than that of the traditional dairy farm.

If we are to survive the coming food security storm, we will have to embrace unashamedly industrial methods of farming. We need to abandon the mythologies around agriculture, which take the wholesome marketing of high-end food brands at face value – farmer in smock, ear of corn, happy pig – and recognise that farming really is an industry, much like car manufacturing or steel forging, one which always works better on a mass scale, but which can still be managed sustainably.

Bespoke is fine for those with deep pockets. As for the rest, we live on a small, overpopulated island with a growing head count and for many big is the only way to go. This is not an endorsement of the worst excesses of the factory farming system. Indeed, only by accepting it can we as consumers get the producers to work to the exacting standards we demand.

Can we afford to ignore these issues? I don't think so. An elitist, belly-obsessed minority, the ones who think the colour plates in the Sunday supplements are a true reflection of real lives if only we all made the effort, may rage against big agriculture and refuse to engage with it. However, when basic ingredients become scarce and prices shoot up on the international markets, their cries will sound increasing hollow, compared to the screams of those who really cannot afford to feed their families. Yes, it has been a very long time since a British food riot, but that does not mean it cannot happen again.

• Food, presented by Jay Rayner, begins at 8pm on Wednesday 15 September on Channel 4

