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Mar 7, 2012 06:32 PM

What equals a complete protein, vegetarian-wise?

I remember from way back in the day being told that beans and rice, or beans and corn equaled a complete protein chain and therefore are a perfect substitute for meat. Food knowledge is so much more advanced now, I'm wondering if anybody here can tell me what various combinations of vegetable proteins form a complete chain- or IF they do.

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  1. Basic introduction: There's 20 main amino acids (the building blocks of protein). There are 9 essential amino acids that you must consume in order to obtain them; the rest your body can assemble on its own. So what's commonly referred to as a "complete protein" is a food or combination that provides an adequate proportion of the 9 essential A.A's.

    But more importantly (and this is a more recent measure) is the PDCAAS - protein digestibility corrected amino acid score. A score of 0 is the lowest and 1 is the highest

    I got the following list off the internet. You can decide

    1.00 soy protein
    0.91 soybeans
    0.78 chickpeas
    0.76 fruits
    0.75 black beans
    0.73 vegetables
    0.70 Other legumes
    0.59 cereals and derivatives
    0.52 peanuts
    0.42 whole wheat

    So the concept of "complete protein" is a bit more complex. Supposedly, amaranth, buckwheat, hempseed, quinoa, and spirulina are all complete protein foods. But they don't have a PDCAAS of 1.0 so each individual food may not be sufficient by itself.

    Moral of the story? Eat a variety of foods. Lots of fun variations on the "bean and rice" theme. Lentils and potatoes. Chickpeas and bread. Tofu and rice noodles.

    1. An Italian dish which sustained immigrants after arriving in the US has complete protein. Pasta e fagioli (pasta fazool) is the dish. Beans and pasta compliment each other by each having the amino acids that are lacking in the other.

      My late mother-in-law made pasta e fagioli with navy beans and ditalini with a tomato sauce base (what else would be used by people of Italian heritage?). Recipes abound on the internet.

      1 Reply
      1. re: ChiliDude

        I like Marcella Hazan's recipe ("Classic Italian"), which calls for making the pasta fresh. The good part is that it's supposed to be "maltagliati", or "badly-cut", meaning that if you have a machine to roll out the dough you just cut chunks off each strip with scissors, directly into the bubbling bean pot. It is beyond delicious; I completely forgot about the nutrition part!

      2. This link is pretty detailed, and comes with an easy grid that shows what goes with what to make complete proteins. Bear in mind that you don't need to mix the combos in each meal, but is effective within 24 hours of each other.

        1 Reply
        1. re: biggreenmatt

          I'm not sure just how "savvy" that vegetarian is, since there is an important error in the chart. Peanuts are legumes, not nuts, and that effects what other types of plant food you would need to eat to get all your essential amino acids.

          Otherwise that chart does answer the OP's question. basically, you combine
          legume + grain
          legume + nut/seed

        2. Just for what it's worth, I don't think people worry as much anymore about combining proteins within an individual meal, which is why vegetarian cookbooks and nutrition books don't harp as much on "protein combining" as in the day of "Diet for a Small Planet".

          If you eat a healthy vegetarian or vegan diet, and are not a bodybuilder or something, you should be Ok as far as both quantity and quality of protein without spending much time thinking about it. Also, I think many would argue that the USDA's RDA for protein is a bit on the high side.

          1. Thanks, all, I've kept abreast of things to a great degree, but it occurred to me that i'd never actually seen a real chart of "complete protein" composites, at least not in the last thirty years, if there was such a thing. I know that people who never eat meat live long, healthy lives, and being an omnivore I feelblessed and lucky that in this day and age in America we have such a dizzying variety of food that if you aren't tragically indigent or ignorant about nutrition your diet can be really great no matter what. It's a latter-day update of my interest in nutrition from the Adele Davis days. Remember her?