Every time you turn around these days, you hear about another person on a medically restricted diet. The reasons range from lactose intolerance to autoimmune conditions to life-threatening allergies.

I’ve been on a restricted diet myself since 2008, when I joined the approximately one in every hundred people who’ve been diagnosed with Celiac disease. That means I have to stay a million miles away from anything containing gluten, including wheat, rye and barley. (Oats are often out too, depending on where they were processed.)

Meals at home pose few challenges because, these days, supermarkets devote whole aisles to gluten-free products and most ingredient lists flag anything that could cause trouble. When I travel, it’s another story, though. At a buffet during a conference, it can be difficult to find anyone who knows, for instance, what a gravy or salad dressing contains. In restaurants, meanwhile, waiters often pass on incorrect info and fail to grasp the potentially serious consequences of doing so. I once ordered an appetizer after being assured it contained nothing but the safe ingredients listed on the menu, only to have it arrive with a breadcrumbs topping. “Oh, yeah, forgot to mention that,” the waiter nonchalantly said when I inquired.

In Atlanta one time, I walked out of three restaurants whose staffs seemed clueless about Celiac disease before finding a place where a waiter pointed me to what he said were gluten-free menu items. I ordered one, then waved goodbye to his credibility as he asked, “Would you like a plate of bread while you wait for your entrée?” (There is such a thing as gluten-free bread, but that’s not what he meant.)

If you’re on a restricted diet, you probably have your own such stories. Before you collect any more, consider these tips for eating on the road, based on my experience:

Google before you travel. Your trip will be much easier if you arrive at your destination armed with a list of places to eat. Google “peanut allergy San Francisco restaurants” and up come links to peanut-free dining establishments there. Search for “Chicago gluten-free” and you get restaurant links plus a Celiac sufferer’s survival guide to the Windy City.

Prepare your hosts. Before you leave home, phone or email your conference organizers or the staff at your hotel to tell them about your diet. Chances are, they’ll do their best to accommodate you, even if that means preparing a special meal. It’s usually much tougher to make such arrangements if you wait to inquire until you arrive.

Speak up for yourself. As I’ve noted, waiters often don’t realize how important it is for some people to stick to their diets, nor do they always know what those diets entail or what particular dishes contain. Don’t be afraid to ask questions and to explain what you require—repeatedly if necessary. Rest assured that the people you’re talking to would do the same thing if they were in your shoes.

Pack snacks. Despite all your planning, you might well find yourself stuck somewhere for the better part of a day with no access to acceptable food. So carry snacks to tide you over. I sometimes rely on a gluten-free bar of roasted almonds, peanuts and sunflower seeds. A banquet it ain’t, but it beats starving until a convention adjourns.

For more suggestions, see “Traveling with Food Allergies,” by Jennifer Leach English.