We might think we love food from far-flung lands, but most of it is tailored to suit our tastes. If you could only ever eat one cuisine again, which would you choose?
Italian, then Indian, followed by Vietnamese? I've never been any good at picking favourites. I'm a mood-driven soul and having my diet restricted to one regional cuisine would feel as though the world were suddenly stripped of colour (although on the plus side, my spice cupboard would be nice and tidy). However, despite a national love of food from far-flung lands - Turkish to Thai, Sicilian to Sri Lankan, Polish to Punjabi - most restaurants here are tailored to suit British tastes. Humans may be omnivores, but we're damned picky omnivores. One nation's succulent horse fillet is another's scandalous counterfeit beef.
There's more to it than geographyWhile terrain, climate, flora, fauna and religion have influenced traditional cuisines, individual cultures also develop unique preferences and aversions within these confines. The anthropologist Jeremy MacClancy has observed that the hunter-gatherer tribes on Earth today - nomadic peoples who do not farm and can eat only what nature has to offer - are as finicky as the next person. The Mbuti pygmies in Angola understandably find the idea of feasting on leopards a bit gross, because leopards eat humans. And primates resemble people too much to be appetising. Kalahari bushmen know about 100 desert plants to be edible, but only 14 varieties are considered desirable. They hunt giraffes, warthogs and antelope, but think ostrich tastes bad, and zebra meat is dismissed as smelly.
Culinary peculiarities also exist among different ancient tribes who live side by side. In Kenya, the Masai drink plenty of cow's milk and blood, whereas the neighbouring Akikuyu people are all about spuds and cereals.
The genealogy of taste perceptionAlong with environmental and cultural factors affecting our food choices, there is evidence that genetic makeup influences how we experience taste. The basic tastes of sweet, sour, salty, bitter and umami are detected when chemicals that produce those tastes bind with certain receptors on our tongues. We all have different amounts of these various receptors, depending on our DNA, and research has shown that sensitivity to one particular bitter compound (which is easy to measure, and is a marker of overall taste sensitivity) varies wildly between different countries. In some parts of Asia, South America and Africa, as much as 85% of native populations are highly sensitive tasters. Ethnic Europeans sit at the lower end of the scale.
The geography of recipesMost of our food loves and hates are learned. Foetuses and breastfed babies can taste what their mothers eat, and have been shown to develop early affinities to certain flavours in their mothers' diets. And when we start eating solids, our concept of acceptable foods evolves quickly. Over time, the way we perceive certain flavours is programmed according to how we usually consume them.
I have mentioned before that in the west, because we associate vanilla with sweet foods, it has come to enhance our perception of sweetness - our brains automatically do this. In east Asia, vanilla doesn't make food taste sweeter because it is predominantly used in savoury dishes. So cultural cuisines don't only differ in dominant ingredients (such as curry spices, parmesan cheese or chillies), they also have conflicting opinions of what goes with what. Traditional European gastronomy is all about pairing foods that share flavours, but a 2011 study (PDF) found that Asian cooking does the opposite and avoids combining similar flavours. The researchers reached this conclusion after identifying the flavour compounds in 381 ingredients that are used internationally, and then studied 56,498 recipes containing them.
The globalisation effectAs the world shrinks, regional preferences will surely be subject to increasing dilution, but this is happening slower than you might think. On the one hand, says international food industry consultant Chris Lukehurst, you'll see Italian teens shunning their local vino in favour of American-style beer. And while coffee and crisps were "almost unknown" in China a decade ago, they're now rapidly growing markets there.
On the other hand, multinational companies alter their products for each market. Take fast food. In China, KFC's headline product is a chicken burger, and both McDonald's and KFC have much more visible salad content in recognition of the three food groups necessary in every meal: grains, protein and vegetables. And rice remains more common than fries.
Even Nescafé gets regional adjustments. "In the UK," says Lukehurst, "Gold Blend has a very low content of robusta and is very smooth and rich in flavour, while in the Philippines Nescafé has a much greater robusta content and a stronger, more full bodied taste. The degree of roasting and the way that the coffee is processed will be adjusted, too."
Meanwhile, what's on the menu at the high-street trattoria will differ not only from country to country but also within Italy, throwing up all sorts of debates about authenticity. Have you ever been shocked when travelling to find that you don't like the local grub nearly as much as you like the version you get back home? If you were stranded on a desert island and could only ever have one cuisine again, which would you choose?
Could you confine yourself to British food? Photograph: Suzanne Plunkett/Reuters