So now that we've established – or at least Peta has – that Glasgow is the most vegetarian/vegan-friendly place in the UK the next question is, which the best country for vegetarians and vegans? In many countries, eating meat is part of the national identity. Think of Australian barbecues, American cowboys and South American cattle ranchers. There was controversy earlier this year when President Obama hosted a dinner for 12 Republican senators, and one of them ordered a vegetarian meal. The identity of the culprit was protected, for fear that exposure could mean losing their seat. TV host Bill Maher commented that American voters would sooner elect a gay president than a vegetarian. Republican senators in Iowa and Texas said vegetarians were ''un-American" and made public pledges to eat more meat.

Still, once you've waved the political madness aside, you'll find that cutting-edge vegetarian and vegan cuisine thrives on America's east and west coasts. San Francisco still benefits from its hippie heritage with decent vegetarian and vegan options as standard around the Haight. San Francisco's Zen Center established Greens in 1976, and various cookbooks from its resident chefs continue to influence the menus of vegetarian eateries worldwide. Millennium, in the city centre, ranks as one of the world's top vegan restaurants with impressive high-end cuisine. Seattle and Portland are hot spots, with vegan bakeries, breweries, clothing stores, bike shops and even – in Portland – a vegan strip joint. However, Peta's choice for the top city in the US this year was, surprisingly, Austin, Texas. In the heart of ranching country, vegan entreprenuers have taken to the streets with food trucks offering tempeh burritos and chicken faux-jitas. It can still be a struggle to find vegetarian food in small-town diners, and it makes most sense to look for sustenance in areas that are highly populated and diverse: big cosmopolitan cities are the best place to look for vegetarian and vegan food.

Barcelona is fast becoming a hot spot for vegetarians, whether your preference is for punk bars or candle-lit fine dining. Elsewhere in Spain, it can be a struggle to explain that vegetarians don't eat ham. Likewise Berlin, another city where countercultures thrive, offers a good deal more for the vegetarian or vegan visitor than more rural German towns. France is notoriously hard work for vegetarians, and it can be far easier to settle for an omelette than to brave the ire of a waiter in a high-end French restaurant, but Paris has more than 30 exclusively vegetarian eateries. Even Russia, where vegetarianism was actually banned and driven underground for decades after the revolution, offers enough meat-free dining experiences in St Petersburg and Moscow to keep vegetarian visitors out of a rut for a week or so.

Any bustling city with a diverse population, cultural leanings and a university or two can generally be relied upon to offer a few exclusively vegetarian cafes, but often the food on offer is disappointingly divorced from the national cuisine. Falafels and hummus, veggie burgers, pizza, pasta and Indian-style buffets are pretty standard all over the place, but getting a vegetarian meal in, for example, a restaurant that specialises in typical Danish food can be very hard work. Vegetarian visitors to Denmark tend to rely on curry houses and Turkish kebab shops that offer falafels, tabbouleh and salad-filled pittas. There's no history of meat-free eating in Belgium – even the chips are often cooked in lard. Belgian vegetarian food makes frequent use of seitan, a surprisingly realistic meat substitute made from wheat gluten. Against all odds, the EVA (Ethisch Vegetarisch Alternatief) has persuaded many cafes and restaurants in its home town, Ghent, to adopt Paul McCartney's Meat-Free Monday idea and serve vegetarian food one day a week – in this case, Thursdays. Ghent also has more vegetarian restaurants per capita than most cities (13 for a population of 240,000).

Of course, there are many parts of the world where vegetarianism is widespread, largely because of religious principles and dietary laws. Hindus, Jains and Taoists all advocate vegetarianism to a greater or lesser extent, and this has a positive effect on the availability of vegetarian food in India and Asia. Between 20% and 40% of India's population is vegetarian – the figure is muddied by the fact that most Indian Hindus do not consider people who eat eggs to be vegetarian. Clear food labelling laws make things easy for vegetarian visitors. Most of the food served at Sikh gurdwaras is vegetarian, not because Sikhs are required to be vegetarian but because they aim to offer food that is acceptable to as many people as possible.

Countries with large Buddhist populations are generally good destinations for vegetarians, although the Buddhist approach to vegetarianism varies and is often misunderstood. The Theravada tradition, dominant in Thailand, teaches that it is all right to eat meat if it is offered to you, the Mahayana Buddhists of Taiwan, Vietnam and Japan recommend vegetarianism, and Tibetan Vajravana Buddhists consider vegetarianism optional. Being vegetarian would have been tricky in a mountainous region centuries ago, so it's hardly surprising that countries with climates that support plentiful harvests of fruit and vegetables tend to have more of a history of vegetarianism than those whose inhabitants are forced to rely on eating fish or animals that do not require lush grazing land.

Vegetarian travellers can also benefit from religious dietary observations that don't directly advocate vegetarianism. In Israel, Kashrut laws require that meat and dairy produce are not served together, making it relatively easy to find vegetarian food. In some African countries, such as Ethiopia, the Christian faith calls for frequent days of fasting, when only meat-free or vegan meals are acceptable.

British vegetarianism has Christian roots, too. Abstinence from meat was considered a form of temperance in the early 1800s, and over the years many radical thinkers embraced the idea. During the second world war, rationing conferred luxury status on meat, but interest in vegetarianism perked up again in the 1960s, thanks to trendsetters such as the Beatles, who brought the idea to a new audience. In today's multicultural society, it is easy to find meat-free specialities from all over the world. Add to that clear labelling regulations, and the UK has to be one of the easiest places in the world to be vegetarian.