Modern Diet Myth No. 2: Legumes should be eliminated from the diet

One of the more baffling pieces of nutrition advice wafting through the internet is that legumes should be eliminated from the diet. This stands in contrast to conventional nutrition advice which encourages intake of legumes. Who would have thought these humble edible seeds, which include beans, peas, lentils and peanuts, would be the centre of a controversy?

At first glance legumes appear to be rich sources of iron and zinc but their critics argue that this is misleading as the absorption of these nutrients is lessened by anti-nutrients, like phytic acid. Phytic acid in legumes binds to these minerals lowering their absorption from the gut. The iron and zinc in meat is more readily absorbed.

The other argument against legumes relates to protein. Compared to traditional ‘protein foods’ such as meat, poultry, fish and eggs, legumes generally have less protein and the protein is of lower quality. That is, some amino acids are in short supply.

So legumes are labelled as inferior foods, compared to red meat.

Legumes as ‘meat alternatives’

It comes as no surprise that these arguments come from fans of the Paleo diet. I suspect what really aggravates Paleo types is the description of legumes as ‘meat alternatives’ in some healthy eating guides. With meat at the centre of the Paleo world view any meat alternative is bound to be attacked.

Healthy eating guides need to cater for all sorts of people, including those who choose not to eat much meat for reasons of ethics or cost. For these people the choice of legumes as a source of protein is usually linked to moderate-to-high grain intake. The protein present in each nicely complements the other and together they provide adequate amounts of ‘complete’ protein. Many of the world’s poorer people rely on the legumes + grains combination to adequately feed themselves, a formula that has proven successful over centuries.

Of course, telling Paleo warriors that there might be benefits to eating both legumes and grains could be a step too far. After all, both foods contain the Paleo pariah – carbohydrate.

A better comparison

Comparing legumes with ‘protein foods’ is a bit misleading. After all, the major nutrient in legumes is not protein; it’s carbohydrate. And the nutritional qualities of legumes look very different when we compare them to other carbohydrate-rich foods. When Professor Noakes and I put legumes though our carbohydrate quality model they were one of the few groups of foods that fell into the highest quality category. The high rating was driven by the essential nutrients and dietary fibre in legumes and their low glycaemic index.

Even if you think that less carbohydrate is better, why would you target one of the best carbohydrate-rich foods? Why not eliminate the worst?

Image: source

Paleo confusion

Paleo advocates are confused. They recommend inclusion of seeds in the diet, but not legumes, which are seeds. They criticise legumes because of their phytic acid content, but then recommend nuts, which contain phytic acid. And they mindlessly bundle all carbohydrate-rich foods together and label them all as bad.

Advice to eliminate legumes from the diet reflects this confusion.


26 thoughts on “Modern Diet Myth No. 2: Legumes should be eliminated from the diet

  1. Legumes for the win! Mineral rich, high in fibre minus the saturated fat of meat. Cooking and soaking reduces phytic acid and besides, phytic acid is a know anti-oxidant.

  2. Hi. Very interesting as always. Would be interesting to confront the Paleo addicts with the World Cancer Research Found recommendations and the increase of bowel cancer among young adults. The FSANZ should apply a Codex only for those kind of non sense.

  3. Here’s the problem…

    “And they mindlessly bundle all carbohydrate-rich foods together and label them all as bad.”

    No. Just no.

    Take a look at what people eating Paleo actually eat. Last I checked, sweet potatoes, honey, maple syrup, dates are all “carbohydrate-rich” foods and all are eaten when doing Paleo. Please stop confusing low-carb diets with Paleo diets. Just because most people doing low-carb tend to gravitate towards Paleo, doesn’t make Paleo a low-carb diet. In fact, the Paleo diet wasn’t necessarily conceived as a low-carb diet.

      • Bill… it’s not an inconsistency. Paleo was designed to recreate as closely as possible what our ancestors ate. Labeling Paleo as “low-carb”is just another attempt to dismiss the diet. That doesn’t equal inconsistency… that equals a misunderstanding.

  4. It’s inconsistent to a nutritionist. Why include some concentrated sources of simple sugars in your diet and exclude others? Regards, Bill

  5. Hi. Very interesting as always. It would be interesting to confront them with the World Cancer Research Found’s recommendations and the increase of bowel cancer among young adults. The FSANZ should not only set the accuracy of health claims for food labels but also for undergraduate pseudo nutrition gurus… ” Primum non nocere” that is the first rule of health care providers….

  6. I’ve been eating ‘paleo’ officially for about 4 years (and inadvertently paleo for many years before that). I’m not confused, I’m not necessarily low-carb (although probably lower carb than ‘conventional eaters’), I’m just allergic and intolerant and coeliac! And eating paleo keeps me away from the foods I don’t digest well and react to! It ain’t rocket science! Which is fortunate because my degree is in biology! It is just nutrient dense and easy to digest. I am however a ‘paleo warrior’ (I have T-shirts with paleo slogans that I wear out of the house!!!) because that is how excited I am about being rash free, having consistent energy, putting my autoimmune condition into remission, resolved blood sugar issues and having comfortable digestion! My doctor encourages me to eat this way.

    • You are one of the unlucky 1% of the population who has a disease which make gluten extremly dangerous to you. How is that relevant for the rest of the population? That ain’t rocket science either. Studies after studies shows that legumes and whole grain decrease diseases risk and ameliorate biomarkers of diseases.

      It’s cool you found something for your ”quite” rare medical condition, but that does not imply anything for anyone who does not have it.

    • Why must you call it Paleo? Why not just “I don’t eat things that make me unwell”?
      The term Paleo is so ambiguous. Even defining it as “eating close to what our ancestors ate” is misleading because the truth is we don’t REALLY know. We DO however know that some of them ate grains and legumes. Intake varied by region and by what was in abundance at the time.
      I eat all foods in moderation. Including legumes AND McDonalds. I am rash free. I have consistent energy. I have an autoimmune condition that is perfectly controlled (without medications). I have zero blood sugar issues. And my digestion is comfortable. My doctor encourages me to continue what I am doing, too.

      • Hi Lene, that is great that that is working for you! The 10 years I did that I just got sicker and sicker! My 10 years of common sense and ‘conventional wisdom’ did me a lot of damage! SO I encourage people who are not having success with ‘moderation’ to try something radical!

  7. There is a BIG difference between eating a small handful of nuts and a big plate of Legumes.

    Just because people choose to not eat meat does not make legumes a good source of protein, it makes it a source but not a good source.

    Paleo can be low carb, but it does not have to be.

    Eating a small to moderate portion of meat along side a plate that is 2/3 veg will have way more nutrition than a plate of legumes and grains no matter how hard you try to white wash it.

    • HI Rob, Could you please point to the passage in Bill’s text that advised us to eat “a plate of legumes and grains” in lieu of a small portion of meat? I find this all or nothing approach to food intriguing. As a beef producer, I have an ample supply of my own beef, but choose to add legumes & vegetables to my meals as a way of reducing the amount of meat we eat at each meal as it is all too easy to over-consume when we have a freezer full. Of course their versatility and flavour is an added bonus.

    • Hello Rob. You are describing a meal, not a diet. A diet based on just meat and vegetables would be very high in protein, which is not good for health. What additional foods would you build into this diet? Regards, Bill

      • Diets are built on meals bill. It is very hard to have a diet if you don’t eat meals.

        Do you have any science that shows eating a small portion of pastured or wild meat, chicken or fish at a meal is bad for you? I know I have never seen one.

        I have seen plenty of studies that show how bad grains are for you and most of them are funded by the whole grain council.

        A diet built on 1/4 plate of meat and 3/4 protein would not be high in protein, it would be high in nutrition but that is a different point altogether. Please tell me why I should eat relatively tasteless low nutrition legumes or even less tasty and even poorer nutrition grains? High carb (sugar) foods with little or no other nutrition in them are bad for you, very bad and that is what grains and to a lesser extent legumes are.

        • Hello Rob. I don’t tell people what to eat – that’s a personal choice.
          But getting back to the meals/diet question: meat and vegetables are both good foods and meat + vegetables is a good meal. But meat + vegetables is not a good diet – it’s too high in protein, which is not good for health. Even if you eat fatty meat with vegetables it’s still too high in protein. Regards, Bill

          • “But meat + vegetables is not a good diet – it’s too high in protein, which is not good for health.”
            Doesn’t that depend on the proportions of the vegetables, and therefore how much carbohydrate they supply, and therefore what proportion of the meal is protein? There is a big difference between half a plate of sweet potatoes and varied other veges and 3/4 plate of lettuce, in terms of how much of everything, including carbohydrate, it contributes to the diet.

            My concerns would be that, unless the vegetables are grown in particularly mineral-rich soils, it would be a diet too low in calcium. Not an insoluble problem, though. The quality and choice of meat and vegetables, and means of preparation would also be relevant. I believe that there have been healthy communities whose diet is mostly meat and vegetables (not low carb, though, as far as I know).

            I don’t believe everyone should avoid grains and legumes, but I don’t see that they are necessary if you have access to an abundant supply of good fruit, veges, and eggs, and at least one of milk, fish, and meat (which of course most people don’t).

          • Hello Kari. Yes, my comment does depend on the amount of carbohydrate supplied by vegetables. Typically, vegetables have small amounts of carbohydrate, except for the tubers, such as potato, etc.
            My concern is that many of the more radical paleo-type diets target carbohydrate-rich vegetables and even fruits for reduction in the diet. Meats and low carb vegetables alone don’t equal a healthy diet.
            Dietary variety helps ensure adequate intakes of essential nutrients. Cutting out whole food groups is a really bad idea. Regards, Bill

      • If as you say grains and legumes are adequate sources of protein then a meal/diet based on meat, veg, grains and legumes would be even higher in protein.

        • “A diet built on 1/4 plate of meat and 3/4 protein would not be high in protein”

          Please explain how a diet where 100% of the plate is protein is “not high in protein.”?

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