Every once in a while you might find a different side dish available on the menu, but at most “Mexican” restaurants in the U.S., that’s it: Your entree always comes with “Mexican”-style rice and beans (sometimes pinto beans or black beans, usually refried beans) on the side. Always. Why are there no other choices? I love enchiladas, tacos, burritos, flautas, but I don’t care if I never see another helping of rice or beans.
My guess would be to keep costs down; beans and rice are very cheap. Mexican food has a reputation of being inexpensive, and keeping wholesale costs down would go far towards lower prices for consumers. It’s also desirably authentic in that poor Mexicans eat a whole lot of each in Mexico.
Besides cost, there’s the fact that beans and rice are nutritionally good food. Beans are high in protein, and they work well with a variety of spices. Rice is a source of carbohydrates and excellent fiber. Relative to many cultures, we in the US eat more meat than we need, and we neglect rice.
I’ll rein myself in, so as not to bore you with some pro-rice sermon. I feel the issue is not why the Mexicans eat a lot of rice, but why we don’t.
The rice served at all the Mexican restaurants I’ve been to has been white rice (cooked with tomato to make it reddish), stripped of its bran coat and devoid of fiber. Might as well guzzle down a couple of spoonfuls of table sugar.
I love rice, and will do myself rice and beans periodically just because they are so tasty. I think the recipe I use is a moosewood recipe, I got teh recipe from my mom, and the original moosewood cookbooks are where she got most of her mexican vegetarian recipes. She also made a killer white bean and kale[?] soup.
Interesting enough, pretty much every meal in Thailand is served with this same white rice, or rice noodles, and yet everyone there is relatively lean*. Or at least they were until McDonald’s, Burger King, Dunkin’ Donuts, Dairy Queen and Starbucks came to town. Nowadays they are catching up with us in heft.
*I understand that BMI is not the only indicator of nutritional health, but it’s probaby a decent start.
Also see: Japan.
Also, I have a question about brown rice. My bag says it has one gram of fiber per serving. So does my bag of jasmine rice. What am I missing here that makes brown rice so much better for you?
Hmm…you appear to be missing actual brown rice. 
Mine has 4 grams of fiber per cup of cooked rice, and my white rice (which I keep around for certain recipes) has “less than 1 gram” per 1 cup.
I’m curious as to what else would be served with tacos and enchiladas. Are there other common side dishes that normally appear with this type food in Mexico?
Probably the same reason fries are served with so many “American” meals. It’s just considered to be “the standard” and deviating from it could cause some upset customers. Perhaps…
It’s probably very regional. When I was in Oaxaca, Mexico, they served some form of cactus with everything - steamed, boiled, baked, in mole sauce, in a cream sauce, in a vinaigrette… They were often frenched like green beans. Very tasty.
While I’m not familiar with food served in Mexico, I know that as a typical American person who eats out sometimes it seems like my protein needs are filled to abundance (or it’s my fault for ordering pasta), my starch needs are filled to abundance, but my veggie needs are not. So more veggies or fruits would be a good thing–even if more expensive and difficult for the restaurant.
Most US Mexican food comes from the Tex-Mex tradition. Which scholars like Robb Walsh have traced back to the Chili Queens of San Antonio. Tacos, enchiladas & tamales were “snack food”–adding beans & rice made a full meal. Or the famous “Combination Plate.”
There’s nothing wrong with good TexMex, but menus have evolved. Instead of the traditional refried beans (which aren’t really refried–but it’s a long story), black beans or charro beans may appear. Fajitas are accompanied with grilled vegetables, guacamole, sour cream, etc. Delicate seafood dishes may just come with rice–not “Spanish” style, but something more sophisticated. Check out Houston’s Pico’s–lots of choices. But there’s still a Tex-Mex section.
Hugo’s is so “traditional Mexican” that they don’t begin the meal with free chips & salsa! But Houstonians have forgiven that violation of Texas Law because the food is so good. (And the drinks.)
In short–rice & beans are traditional. But traditions change–even at Houston places less high-end than Hugo’s. Maybe some Florida restaurants will try to push the boundaries–adding more Caribbean tropical dishes to Tex-Mex?
(Now I’m hungry.)
I dunno about the history of rice, corn or beans in the Mexican diet, but academics in Pre-Columbian studies have identified a “corn-beans-squash complex” in the diet of some Native American nations, in which they grew those three foods together very efficiently on earthen mounds, and later ate them together in the same meals. Probably something very similar had been discovered by the Pre-Columbian Mexican Indios [?], given the likely paucity of meat in the average peasant’s diet.
When digested in tandem, the simple, inadequate vegetable proteins of the corn and beans are recombined by the digestive system into much longer protein chains. In other words, corn and beans together make an adequate meat substitute for those times when real meat may be in short supply.
As for processed “white” rice, that is a debased modern food that is indeed stripped of virtually all its nutritional value, although it remains a source of carbohydrates. It seems counterintuitive to me that white rice could become as popular as it has, especially in regions traditionally challenged to provide sufficient animal protein to most of the populace (esp. in the Far East). In the case of Japan, the rise in recent generations’ average height (IIRC, young Japanese men today are some 8" taller than their grandparents or great-grandparents’ generation) and weight indicates that the Japanese who came of age prior to WWII were truly starved for protein – yet the dietary staple was and remained sticky white rice.
The major advantage to polished white rice is that it can be stored for long periods of time. You can’t store brown rice for more than one winter because the fat in the germ will go rancid.
But there’s sort of a cult of white rice all through asia. White rice is pure and refined, brown rice is dirty and coarse. It’s weird.
No weirder than the Western preference for white bread over wheat or sourdough until very recently. White rice and white bread require more processing than brown rice and whole wheat bread, so, all else being equal, they are more expensive. The rich can afford them, the poor can’t, so they become associated with social prestige. The idea of unprocessed food being more desirable than processed is quite recent, historically speaking. So is the discovery of vitamins and the discovery that whole wheat bread and brown rice have some vitamins that white bread and white rice don’t, for that matter. It wasn’t discovered until the late nineteenth century that eating brown rice instead of white could prevent beriberi.
Probably worse than in Europe at the time. Remember, the pre-Columbian North American Indians didn’t have any domesticated meat animals except the dog.
Any supermarket? Maybe any supermarket in Florida.
I know from experience you can get nopales in Alabama and Kansas. But you want to get the ones with only cactus, nothing else (no onions or whatnot).