I maintain a restaurant list for the 400+ members in our local Eat Smart, Live Longer Club. In that list, I identify restaurants that have items on the menu that meet our club's purpose for eliminating or minimizing meat and dairy products. The list currently includes 33 restaurants. For each restaurant, I identify the dishes that do not have any meat or dairy products as well as those dishes that can be ordered and still make a meal by asking the restaurant to hold the meat or dairy product. An example might be a veggie pizza where the restaurant is asked to not put cheese on it.
Unfortunately, I can't have a list that meets all of our criteria of no oil, no salt and no added sugar too. If I tried to publish such a list of restaurants, the number, at least from what I've found so far, would be zero or close to it. The closest I have found to finding a meal like that outside the home is to make a meal out of the food bar at Whole Foods Market or to order a veggie sub at some place like Publix and not have any oil or cheese put on it. In fact, when I'm traveling, I often find that grocery stores make a great option for stopping along the interstate for a bite to eat.
Another option, which is also usually easy to find when traveling, is a place with a buffet. Many vegetarians and vegans may not think about a place like Golden Corral, but they actually have a lot of good options for avoiding meat and dairy as well as excess amounts of salt, sugar and oil. You just have to pay attention to what you're putting on your plate. I will usually make a large salad from the salad bar and get fruit from the dessert bar. For my main course, I will select items from the hot bar that are least offending. Nutritional information for each item is published on their website. So, if you have a smart phone or a tablet with you, then you can plan out what you're going to eat.
Asian restaurants are some of my favorites. I'm particularly partial to Japanese restaurants and Thai restaurants. There are usually lots of vegetarian and vegan options available at these restaurants. But they do pose problems with oils and sodium and many Chinese foods have sugar added to them. And to make matters worse, oils used in Asian cooking can be worse than other oils in terms of their omega-6 and PUFA content. So, depending on how much you are watching these items, you may want to be careful.
I know at least one person who hands the waiter or waitress a slip of paper that says he eats no meat, dairy, oils, salt or sugar. Then he lets the waiter or waitress work with the cook to figure out something he can have. He tells me that it works very well, and he's had some delicious surprises doing that. The idea sounds intriguing, but I have to admit to not having done that myself. Maybe, that's because when I eat out, I have a hidden desire for some of those things as long as I don't know they're there. Hmmmm!
But that does bring me to the point that we can actually get a decent restaurant meal almost anywhere. Just don't look at the menu. All restaurants are going to have a supply of fruits and vegetables in the kitchen. So, just tell them that's what you want. For example, yesterday I went out for breakfast. Instead of ordering off the menu, I told the waitress that I wanted some spinach, onions, peppers and mushrooms cooked on the grill with potatoes. I could have added to cook with water instead of oil, but I admit to not having done that in this particular case. But the point is, every restaurant is likely to have vegetables. So, there is always something that can be made for you.
So, enjoy the restaurants when you go. Just recognize that you're unlikely to get a perfect meal in one. But you might be able to come close.