Traveling to a new country can be challenging enough, learning new customs, striving to act as the locals do, and sampling as much as you can of what the country has to offer.
Enter vegetarianism. Yes it hinders some of your experiences, yes it's a pain in the ass, no you might not always know if what your eating is truly vegetarian.
I have been vegetarian for over 40 years and abhor the thought of eating a dead animal. No soapbox here, that's just where my line is drawn. Everyone has their own line. Keeping that line in place while traveling, well now that's the interesting part.
Some countries are easier than others. For instance India (where most of the country is
vegetarian) is the only place that I've actually been able to eat the street food - it was wonderful!
Whereas places like Comoros barely understand what vegetarian means and almost all they eat is seafood.
View each country for country-specific foods and tips.
1. Learn Some Local PhrasesFirst order of business. LEARN HOW TO SAY "I am vegetarian" IN THE LOCAL LANGUAGE. It may not be a literal translation so make sure you find a local who speaks your native language (or English) who can tell you how to properly get your point across in that region.
Depending on your needs, make sure to learn the terms for meat, chicken, seafood, lard, stock, eggs, dairy, and any other local ingredients. For instance in Thailand I always say "no fish sauce" (mai naam plaa) and in Mexico I usually ask about chicken bouillon (bulion de pollo).
2. Watch for Meat StockBe aware that most people/countries seem to think that meat stock or say, soup that has had the chunks of meat pulled out of it IS vegetarian.
3. Be Willing to Eat for the Sake of SustenanceThere are times when the best you'll get is some plain rice and maybe a vegetable, or a greasy snack. This is rare, but be willing to take what you can get if it comes to that. You'd be surprised how yummy a few bananas and some peanuts are when you're on a long bus ride.
4. Give it TimeEventually you'll figure out how to eat in each country. Each place will have at least one go-to dish, or perhaps a special way to order a local dish. Maybe there are supermarkets or a certain vegetarian street food. Sometimes it takes a while to get your culinary bearings.
In times of pure desperation, I have survived on a few raw carrots and a loaf of french bread while trying to figure out how to eat in a new very rustic country that had seemingly no shops nor restaurants.
5. Use Your FallbacksOf course the most desirable option is to eat the local food. It's not only the best cultural experience but is probably also the tastiest and the cheapest. But if that's just not going to work out for you, unless you are someplace really remote, there are other options.
Some ubiquitous foods: bananas, rice, peanuts, yogurt, cheese sandwich (likely with a cheese single), pizza (although you never know what a given country's interpretation of pizza might be!). I'll usually bring a ziploc full of nuts and a few granola bars with me from home if I'm traveling to a third world country as "emergency" food, but I seldom really need it.
I hate to even say these words but 7-11 is your friend. When in a pinch, get a yogurt or some pastry. Of course a supermarket is even better for things like making your own sandwiches or milk & cereal.
Then there are the westernized tourist restaurants. Especially in super touristy places like Bali and Chang Mai in Thailand, you are likely to, but not assuredly, going to find something that's actually vegetarian. Still keeping in mind that their interpretation of western food is typically a bit far from on the mark! I can't tell you how many times I've tried to order pasta while traveling and every time tell myself NEVER to try again. I think the last past alfredo I had was some spaghetti noodles with a can of cream of chicken soup over it!!