Healthy Vegetable Sources of Protein and Iron

by | Aug 9, 2010
Collards, Carrots and Lentils

Collards, Carrots and Lentils

Today’s post is written by a long-time Summer Tomato reader, Matthew Shook. Matt refers to himself as an herbivore, rather than a vegetarian, which I love. To me the term herbivore implies an intent to live from vegetables instead of simply consuming them in an exclusive way.

Although the term omnivore better describes my own eating habits, I do think plants are the cornerstone of a healthy diet. Moreover, although I eat animals I prefer to rely on plants as my primary sources of protein and iron. My reasons include health, ecology and economy.

Those of you who knew me back in the day know how very weird this is. I always considered myself a carnivore through and through, and the thought of a meal based entirely on plants seemed borderline insane. Now for me it is more normal than abnormal.

For one thing, relying on plants makes cooking and shopping a lot easier. It’s also cheaper and, as I’ve come to learn, just as tasty.

Since I have learned more about food and health I have come to appreciate that vegetarian sources of protein are not simply a substitute for meat (how could beans replace steak?), but are an essential part of a healthy diet in their own right.

Whether vegetarian or not, I encourage you to incorporate healthy plant sources of protein and iron into your healthstyle.

For this I turn you over to Matt, our resident expert on herbivory. For more wonderful vegetarian recipes visit his blog Recipes for Disaster.

Healthy Sources of Protein and Iron From Vegetables

by Matthew Shook

When I became an herbivore six years ago I had a very elementary understanding of proper nutrition. Becoming an herbivore was very simple for me–I just stopped eating animals. I soon discovered that becoming a healthy and well-nourished herbivore was a far more complex endeavor.

New herbivores often face three obstacles at the beginning of their diet transition. One is a self-perceived lack of acceptable food options and diversity. The cereal, rice, beans and pasta get old real quick. This is why herbivores often expand their interests to ethnic and unfamiliar foods.

The second obstacle, unbeknownst to many herbivores, is a lack of high-quality protein and highly-absorbable iron.

A third obstacle during my transition was trying to convince my friends, family and loved ones that becoming vegetarian can be a healthy decision. My parents swore that if I didn’t eat meat I would wither away and die within one year’s time. In their eyes, it’s a miracle I’m still alive.

The following is a review of some of the best options for maintaining a healthy vegetarian or vegan diet, but is also useful for health-conscious omnivores.


Most North Americans get more than enough protein in their diet (some even argue they consume too much protein). The problem, especially for herbivores, is that not all protein-rich foods are created equal.

Enter the “complete” protein.

A complete protein contains all of the nine essential amino acids (the building blocks of protein), those that our bodies cannot produce themselves. So really, this should be a discussion of our need for amino acids, not necessarily protein.

Meat, fish, and dairy products are sources of high-quality protein, but herbivores need to look elsewhere for their fill of essential amino acids. (Sidenote: Some vegetarians consume dairy products, but relying on dairy as the foundation of your diet is, in my opinion, a very unhealthy way to go.)

This first vegetarian protein source is what I call “an herbivore’s best friend.”

Quinoa, while technically a seed, is often referred to as a “supergrain” from South America. It contains complete protein and is one of only two sources (the other is soybean) that are not animal-based. I have tried white, red, and black quinoa and find them all to be delicious when properly prepared. The red and black varieties tend to be a little “crunchier” than the white. 

Unlike many foods, quinoa is just as nutritious cooked as it is when sprouted and consumed.

(Here is the Summer Tomato recipe for Mexican-style quinoa salad.)

Amaranth, while not a complete protein, contains a large percentage of essential amino acids and is an outstanding source of plant-based protein. It is a “pseudograin” like quinoa, and can be used in dishes such as stir-fries, soups or just as a side dish to compliment seasoned vegetables. It can also be made into a pudding or be ground up into flour.

There are a wide variety of legumes (aka beans) capable of fulfilling an herbivore’s protein and palate requirements. Legumes are generally very low in the essential amino acid methionine, and therefore pair well with grains/pseudograins which fulfill this gap. Black beans, lentils, and chickpeas are three of the most nutritious and flavorful legumes.

This discussion would be incomplete without mentioning the most popular and highly debated legume: soybean. Soybeans have the highest amount of plant-based protein, by weight, of any other food. (Hemp seed and lentils are second and third respectively.) 

Soy can be a bit of a touchy subject as many health-minded individuals disagree about the long-term benefits of introducing the many forms of soy into your diet. Soy can be consumed as whole soybeans, edamame, tofu, tempeh, soy milk, textured soy protein, etc.  Also controversial is the genetic modification of the typical American soybean (thank you, Monsanto).

Tofu and tempeh are concentrated forms of soybean, and thus have high levels of protein. Typically unprocessed foods hold more nutritional value than their processed counterparts, but one can argue that tempeh (a fermented form of soybean) is the healthiest form of soy. The argument is that unfermented soy products like tofu contain “anti-nutrients” (phytates, enzyme inhibitors and goitrogens), which can cause digestive problems and nutrient deficiencies.

I limit my soy intake to very moderate amounts of tempeh and utilize it as a complement to well-balanced meals.

This last one should come as no surprise to Summer Tomato readers. While not an option for vegans, eggs can provide a great deal of nutrition to a vegetarian diet. Eggs contain all of the essential amino acids and are particularly beneficial to herbivores as a source of active (highly-absorbable) vitamin B-12, which is only found in significant portions in animal-based food.

What are your favorite vegetarian sources of protein?


Iron is essential to any healthy diet, herbivore or otherwise. Iron is a vital part of hemoglobin in blood, and a failure to absorb an adequate amount can lead to iron deficiency anemia. 

There is a big difference between consuming and absorbing an adequate amount of iron.

Two types of iron exist in the human body: heme iron and non-heme iron.  Heme iron can only be obtained from animal sources such as cow, chicken and fish. These animal sources contain about 40% heme iron.  The remaining 60% of animal-based sources, and 100% of plant-base sources, are comprised of non-heme iron. 

The semi-bad news for herbivores is that heme iron is well-absorbed and non-heme iron is less well-absorbed. The good news is there are other foods you can eat with your meal that enhance the absorption of non-heme iron sources. Non-heme iron enhancers include fruits high in vitamin C, peppers, broccoli, tomatoes, potatoes, Brussels sprouts and white wine.

Spinach is one of best sources of iron available for herbivores, especially when cooked. I consume spinach regularly both raw and cooked, and find it is an excellent addition to numerous recipes including soups, salads, stir-fries and smoothies. 

I have read that spinach is an iron inhibitor (reduces the absorption of iron), but when paired with iron enhancers the essential element is readily absorbable.

Swiss chard, turnip greens, and bok choy have decent but not spectacular amounts of iron.

There are a few legumes that are excellent sources of iron. Lentils, lima beans, kidney beans, black beans, chickpeas and soybeans are the best sources in the legume family.  The wide range of flavor from these legumes enables herbivores to get more than enough iron from a variety of cuisines.

(For more nutrition information on lentils and the recipe for the dish pictured above read the Summer Tomato recipe for collards, carrots and French green lentils.)

Chickpea hummus, black bean burritos, dahl (lentil) soup and lima or soybean stir-fry are fantastic recipe ideas using iron-rich legumes. If you choose soybeans, be sure to add some iron enhancers to the meal since they are considered iron inhibitors as well.

Quinoa and amaranth, the two psuedograins mentioned for their high protein content, are also good vegetarian sources of iron. I try to maintain a varied diet by frequently switching up the different greens, legumes and (pseudo)grains in my meals.  I’ve included one of my favorite recipes that features many of these protein and iron-rich ingredients.

Black Bean and Quinoa Burrito

What are your favorite vegetarian sources of iron?  Are you concerned about iron inhibitors in your diet? Are you or someone you know ever been chronically anemic?

Originally published August 19, 2009

Tags: , , , , , , , , , , , , , , , , ,
You deserve to feel great, look great and LOVE your body
Let me show you how with my FREE starter kit for getting healthy
and losing weight without dieting.

Where should I send your free information?
  • This field is for validation purposes and should be left unchanged.

19 Responses to “Healthy Vegetable Sources of Protein and Iron”

  1. Great site! Very interesting and very useful information. Look forward to reading more of your posts.

  2. sian says:

    Just wanted to say thanks for stopping by our web site and leaving a comment about marathon traning and losing weight-I just finished reading your whole bio and it sounds like me…only you are more in the future with your diet/ fitness than I am…still don’t have it down-some days no carbs-some days no meat…urghhhhh

    I am going to follow your site and become a RSS subscriber so I can learn how to do it all-thanks so much-so glad I found your site!

  3. Lisa Scott says:

    This is a wonderful little article! It’s great that you not only listed which plant foods are good sources of protein and iron, but delved further into it and explained why! Very informative 🙂

  4. mango says:

    Wasn’t the “complete protein” myth debunked over 30 years ago?

    Eat what you want (fruits, vegetable, greens, nuts, seeds, etc.), you will never be protein deficient.

    • Darya Pino says:

      Yes and no. Vegetarians should still make an effort to get all their amino acids. It just appears that it doesn’t need to be all in one meal. You’re right, a diverse diet should take care of it no problem.

  5. Emma says:

    Delicious looking recipes I’ll be sure to try them out. I didnt know all of these protein and iron sources but it will come in handy. Recently ive been told i have an iron deficency so I’m trying to help control it through diet as well as various supplements which i’ve been told to initially go on by my nutritionist. With tasty food like this hopefully I can control it!


    • George G. says:

      Grassfed red meat is amazing with iron deficiencies. My iron was so low at one point I couldn’t donate blood. Now it’s fine, without supplements.

  6. I discovered quinoa this past year and a very unique way to prepare. I toast/roast it. There are two recipes on my blog for quinoa this way.

  7. Lauren says:

    Thank you for this post! I am a pseudo vegetarian and manage to maintain appropriate iron levels because I eat a good range of vegetables and legumes when I can. (Great recipe ideas on summer tomato).
    Darya, what do you think of the effect of phytates in iron absorption? I am constantly finding conflicting information, such as it reducing iron absorption but on the other hand I have found information saying that the effect is negated if you consume vitamin C with you non haem source of iron.
    And also, my professor in nutrition told me that a small amount of haem iron will increase your absorption of non haem iron significantly. What do you think about that?

    • Darya Pino says:

      Thanks for asking, Lauren. I’ll have to do some research to give you a proper answer. Like you I don’t know the answer to this and still have pretty high iron levels (esp for a female), so it is not something I think people eating healthfully need to worry about. I’ll try to find the study your professor refers to and will get back to you.

  8. Stephen Wise says:

    Try quinoa with cooked salmon – It is one of the greatest things a local bistro here offers.

  9. Jeff A says:

    What is the ideal amount of protein to be consumed daily? Is it different for male and female? Does it matter if you are weight training? Everywhere I look there are different recommendations.

    • Darya Pino says:

      It’s not just different for male and female, it’s different for everybody. It depends on your goals, activity level, diet, etc. Eat as much as you need to feel satisfied. If you’re trying to build muscle, eat more and workout hard.

      • Jeff A says:

        Do you know of a calculator that might give me a RDA for protein that takes into account all the factors you mentioned?

  10. Jared says:

    Surprisingly, some vegetables actual have better amino acid profiles than beef. I put together a list of vegetables high in quality protein, with a few the best examples. The only problem is that you have to eat a lot of them to get as much protein as that found in a steak. Fortunately with the right variety of foods (as you’ve pointed out), it’s not that difficult to obtain vegetarian sources of protein.

  11. Lynn R says:

    My Wife has migraines, is diabetic, has high blood pressure, and a pace maker implanted. can you suggest food that she can eat to get all the iron and protein she needs. She cannot do beef, chicken, spices anything processed, no cheeses
    I have been trying for over year now to keep her fed well but I feel I am failing
    Please help

  12. Bob Greene says:

    Your information about vegetable-sourced protein is helpful. However, not all your readers may be concerned about iron.
    For example, men will not need iron nearly as much as pre-menopausal women, and therefore may steer clear of articles addressed to women readers.
    In addition, iron and glucose are primary elements in tumor development, and seeking out additional dietary iron is to look for trouble.
    With the idea of modifying diet to minimize iron, what vegetable choices do you recommend?

  13. Bev. Hilliker says:

    I’m looking for foods that my husband can eat so that he doesn’t absorb too much iron because he has hemochromatosis. Is there any such food/s that would be beneficial for him?

What do you think?

Want a picture next to your comment? Click here to register your email address for a Gravatar you can use on most websites.

Please be respectful. Thoughtful critiques are welcome, but rudeness is not. Please help keep this community awesome.