Don't Worry About Finding 'Complete' Proteins

Note from Ryan: This was originally published on Furthermore, it’s worth revisiting here.

As a registered dietitian, nearly every week I hear clients, colleagues, journalists, coaches, students, friends, bus drivers, and barbers use the terms ‘complete’ and ‘incomplete’ proteins. We’ve become obsessive in our quest to consume more and more of the former. And this has led to a diet that overemphasizes animal products at the expense of plants. The ripple effect of a diet focused on animal food extends far and wide, influencing not only our personal health, but environmental sustainability and humane livestock production (and whether we like it or not, these last two influence all of us).

The idea: ‘Complete’ proteins supply the necessary proportions of all of the essential amino acids (nitrogen-rich compounds that our body cannot produce). If someone only ate a single ‘complete’ protein food for the day, and nothing else, they would meet 100 percent of their daily protein needs. Chicken, beef, eggs, fish, and soy are often referred to as ‘complete’ proteins.

‘Incomplete’ protein food sources, on the other hand, are often plant foods. The terminology suggests that if someone was to subsist exclusively on an ‘incomplete’ protein food, they wouldn’t meet 100 percent of their daily protein needs; they’d likely fall short of least one amino acid. Foods like rice, carrots, and beans are referred to as ‘incomplete’ proteins.

For years, health professionals thought that if one food contained a smaller amount of one essential amino acid, we’d need to pair it up with another food at the same meal in order for it to be useful to the body. Rice falls a bit short in lysine, for example, but black beans have plenty of lysine, which gives us black beans and rice.

After all, we need each amino acid in different amounts to build a protein—kind of like how you need different supplies (bricks, nails, wood) to build a house. Without enough of one supply, the house suffers.

Today, though, our knowledge and perspective has evolved. And classifying a food as a ‘complete’ or ‘incomplete’ protein (for the well-fed person in a developed nation with protein in their nutritional bullseye each day) is flawed and antiquated.

There’s no doubt that certain foods have more amino acids than others. But in my opinion, with a little thought and effort, it’s nearly impossible to fall short on getting enough essential amino acids in your diet, even if it’s plant-based.

Furthermore, continuing to use terminology that steers people away from having foods like legumes as a protein source is irresponsible and misguided, especially when you account for added benefits of eating more plant foods, such as decreased likelihood of chronic disease, a smaller environmental footprint, and improved animal welfare.

Nutrition science is a recent science, and it’s very complex. Food is made up of countless compounds that we are continuing to learn more about. And beyond nutrients, we all have unique differences in how we digest and process foods. This can make attaining certain nutrients from certain foods more difficult or easy depending on our genetic makeup, health history, gut microbiome, and medication use—things that cannot be captured in the ‘complete’ or ‘incomplete’ label.

So instead of focusing on whether your protein source is ‘complete’ or ‘incomplete,’ follow these three guidelines.

1. Eat enough food to support a healthy body size.

If we don’t meet our energy and calorie needs (if we crash diet, fast for extended periods of time, or don’t eat enough during high volume periods of training), both dietary protein and proteins stored in the body might be diverted to other functions that protein is not ideal for, like producing energy. Eating enough calories allows protein to do what it’s meant to do in the body: aid in growth, repair, development, and in the synthesis of hormones, enzymes, and neurotransmitters.

2. Build a diet around a variety of foods.

When a diet is built around a single food group, there’s a much better chance that the person will run into a nutrient deficiency problem. If you were only eating steak, for example, you might meet your protein requirements but you’d fall short on fiber, vitamins A, C, E, K, D, some B vitamins, calcium, magnesium, potassium, copper, and manganese. For people who love numbers, an active adult should aim for between 1.2 to 1.7 grams of protein per kilogram of body weight, or 82 to 116 grams of protein each day for a 150-pound adult. This protein can come from a variety of vegetables, fruits, whole grains, legumes, nuts, seeds, and animal foods.

3. Include at least one cup of cooked legumes each day.

Or closer to one and a half cups if you’re over 160 pounds. Legumes are a rich source of the essential amino acid lysine. If someone eating a highly plant-based diet is going to fall short in one of the essential amino acids, lysine is probably the one. That’s because it’s found in lower amounts in most plant foods—other than legumes, quinoa, pumpkin seeds, pistachios, and amaranth, that is.

All Plant-Based Diets Are Not Created Equal

I was recently interviewed about the hierarchy of plant-based diets. I wanted to post my full response here…

*All plant-based diets are not created equal. What is the healthiest of plant-based diets? I know above you state Most healthful dietary patterns a) get people thinking about daily food choices; b) emphasize the consumption of more minimally processed foods; and c) ensure a greater nutrient intake. Together, this often leads to a healthier body size, more energy, improved sleep, a better mood, and so forth. What do healthy plant-based diets have in common? Or would you still stick by that quote?

Healthy plant-based diets fall under those same general criteria. 

The interesting thing right now with plant-based diets (and this is happening with paleo diets too) is that the food industry has started to get involved. This has been positive and negative. It's now possible to get lentil pasta, sprouted spelt bread, and almond butter at most grocery stores. This is probably a positive thing for our collective health in the U.S.! 

At the same time, it's also much easier to get vegan mac & cheese, vegan ice cream, and vegan chips. If someone switches from eating "regular" mac & cheese, ice cream, and chips to the vegan versions, and that's the only change they make in their diet, I wouldn't anticipate any noticeable health improvements. Now, if someone is eating mostly minimally processed vegetables, fruits, legumes, whole grains, nuts/seeds, and then they include vegan mac & cheese, vegan ice cream, and vegan chips about 10% of the time (give or take), it would still be very health promoting diet! There's no need to completely eliminate all highly processed foods. 

Another important point here is that not everyone makes dietary changes for personal health reasons. Some people want to eat a diet that doesn't support over-reliance on livestock, has a lighter environmental footprint, and promotes more tolerable working conditions for farm laborers. So, while eating vegan mac & cheese, vegan ice cream, and vegan chips might not support personal health goals, in some cases, it could still be supporting these other "bigger-than-self" goals.

(Practical personal example: I buy Fair Trade chocolate bars and non-dairy ice cream. I don't do this because I think it's going to improve my personal health. But I do believe it's a step in the right direction for farm laborers and animal welfare) :) 

When personal health is your main focus, the big question to ask when making any type of dietary switch is: What would I be eating instead? This can clue you in to whether or not it's a positive or negative decision for your health. 

*Do you ever find that people who eat plant-based diets have unhealthier behaviors or sort of hide behind their plant-based diet and eat other stuff that is seemingly healthy but really isn’t? Please explain.

Sure. This is possible under any dietary label. Some people might be craving strict rules and regulations around their eating. This can often happen when they are disconnected from body cues and preferences. They use a dietary label to grant themselves permission to overeat certain foods, while overly restricting others. This would be disordered eating territory, and can lead to all sorts of physical, emotional, and social problems. If someone suspects they have some disordered eating going on, I would encourage them to get this sorted out first, before trying to abide by any dietary labels. 

*What are some signs that your plant-based diet isn't working for you?

Well, it's hard to say for certain, as so many factors influence our overall health. No matter if someone is feeling crummy or fantastic, it might have a lot to do with their diet, or it might have very little to do with their diet.

Generally speaking, I would suggest 2 things here:

1. Keep an eye on health markers during your annual physical exam. If anything seems out of whack (e.g., lab values, blood pressure, weight, etc) talk with a doc or dietitian about if it could be diet related.

2. Keep tuned into your body. Intuition is often underrated when it comes to personal health. If you've made some dietary changes, and coinciding with those dietary changes is a general feeling of crumminess, major weight fluctuations, digestive problems, and so forth, it might be a sign to make some adjustments to your food/beverage intake, preferably with professional assistance. 

*What should you look for / focus in on when sticking to a plant-based diet? Why is this so important

What you're eating, not on what you're avoiding. Great, so you avoid meat, fish, dairy, and/or eggs. What are you actually eating every day? Hopefully plenty of minimally processed vegetables, fruits, legumes, whole grains, and nuts/seeds!

And avoid the all-or-none trap. It's common in the U.S. to give ourselves 2 options when it comes to plant-based eating: Option 1) Vegan/vegetarian. Option 2) The status quo (which is often animal products at every meal, or at least every day). There's a lot of middle ground to explore here. And if the middle ground allows you to feel better and consistently eat more plant-based in the long run, it might be your best option. 

Reconciling Supplement Use with Plant-Based Diets

Question 1) How do you reconcile a 100% plant-based diet with the fact that this will cause us to miss out on key nutrients, specifically vitamin B12 which you recommend supplementing multiple times throughout your book. It's not that I'm opposed to supplementation, but I'm having more of a philosophical debate on how healthy a 100% plant-based diet truly is if it would cause our bodies harm by missing key nutrients.

I guess I think of this from a few different angles.

Angle #1) All dietary patterns have pros and cons. Some dietary patterns are more nutritionally complete, some might fall short on a few nutrients. Some dietary patterns have a lighter environmental footprint, some are quite damaging to the planet. Some can be sourced mostly locally, some require more transport miles, The list goes on. So, while a 100% plant-based diet might require vitamin B12 supplementation (a con), it also has a lot of pros (light on the environment, nutritionally rich in other various micronutrients, promotes animal welfare, decreases chances of chronic disease, etc.).

Angle #2) I know that there is often a push in the nutrition world to get all nutrients from whole foods, without any type of modern intervention. And if someone cannot achieve adequate nutrient intake from whole foods alone, they are sometimes viewed as flawed or inferior. But I like to step back and consider all of the different areas where we rely on modern, man-made interventions to allow for a more seamless and healthy existence. We have cell phones, cars, medications, gyms with dumbbells, electricity, refrigerators, etc. These things aren't "from the earth" or "natural". But they can be very helpful in certain situations. So, I don't think using a man-made vitamin B12 supplement to round out a diet makes the diet flawed. There are plenty of omnivorous dietary patterns that lack certain nutrients and also require supplementation. No matter how someone eats, it's very difficult to meet all micronutrient needs with our soils becoming more depleted.

Angle #3) In parts of the world where people eat a highly plant based diet due to income limitations and not as much accessibility to meat, vitamin B12 deficiency still isn't very prevalent. This is because in these parts of the world they are still eating plants that have more bacteria on them (and vitamin B12 is a product of bacterial fermentation). In the US, we have such a sterilized food supply (which can be life saving in some cases, like ensuring that foods don't have harmful microorganisms) that we don't have access to the vitamin B12 on plant foods. So, it might be more of a food system issue rather than a dietary pattern issue.

Angle #4) Why does someone need to draw a line at 100% plant-based eating? In the past several years I’ve really transitioned away from encouraging people to adopt a vegan/vegetarian diet. Instead, I talk about the idea of ‘finding your minimal effective dose of animal products’. This is the amount that allows you to be happy, healthy, and sane while also minimizing environmental damage and harm to animals. Finding this minimal dose could allow someone to avoid supplementing other nutrients, if that makes them uncomfortable.

Thoughts on Non-Dairy Milks

A couple of big picture thoughts to begin with:

  • While crop products like almonds, oats, rice, peas, etc. don't completely eliminate animal welfare concerns (because an indirect outcome of crop production can be harm to surrounding wildlife), these plant-based milks allow consumers to avoid the notable inhumane practices towards animals on industrialized dairy farms. Not all dairy farms treat animals inhumanely, but the vast majority in the U.S. have questionable practices. For more about humane forms of dairy, see Cornucopia and Certified Humane.  

  • Non-dairy milks can be purchased heavily sweetened or unsweetened (with options in-between). For most people in developed countries, consuming more added sugars isn't a smart idea for long-term health. Further, sugar production presents an environmental burden. So, when possible, aiming to get non-dairy milk lightly sweetened or unsweetened makes the most sense for personal and planetary health.  

  • Whenever someone is thinking about adding a new food/beverage into their rotation, it's worth asking the question "What's the alternative?" In other words, if you eat or drink X, what are you not eating or drinking? When it comes to milk, this is especially worthwhile to ask, because a straight swap from cow's milk to a non-dairy option will offer pros and cons, but rarely is it an equivocal nutritional swap. While drinking any form of milk (dairy or non-dairy) isn't essential for human health, some people do rely on milk as a source of important nutrients in their diet, so it's important to know the nutritional trade offs.   

  • There's an obvious benefit or detriment to any one of these milks when considering food intolerance/sensitivity. If someone is allergic to tree nuts, then almond milk is a bad idea. If someone doesn't tolerate quinoa milk, then quinoa milk is a bad idea. And so forth.  

Almond milk

Pros: Offers beneficial fats. Not a very strong taste. Good for low-fodmap eaters.

Cons: Doesn't offer much overall nutrition, as most store versions of almond milk contain mostly water (this changes if you make it at home). Almond production, especially on farms without any sustainability measures in place, can have negative outcomes on the environment (this goes for all tree nut based milks). 


Soy milk

Pros: Legumes in general offer a lot of nutritional bang for your buck. You get some beneficial fats, protein, fiber, vitamins, and minerals. Also, when grown under certain conditions, soy can be a more environmentally efficient form of milk than most others (including tree nut and cow's milk).   

Cons: If someone consumes high quantities of soy foods each day, along with soy milk, this might be a cause for concern (I would echo this with any single food that dominates ones diet). 


Oat milk

Pros: Generally a more environmentally efficient crop to grow. And oat consumption is linked to beneficial health outcomes. 

Cons: Conventional varieties of oats are treated with a notable pesticide (glyphosate). Residues can be of concern when consumed regularly over time. 


Rice milk

Pros: Good for low-fodmap eaters.

Cons: Arsenic was applied to crops in the 1970s to control pests, and it accumulated in the soil. Now it turns up often in rice. If someone is consuming whole rice, rice crackers, rice protein powder, and/or rice flour, then they should be concerned about getting too much arsenic in their body (for more, see here).  


Coconut milk

Pros: More environmentally efficient to produce than almond, walnut, macadamia, and cashew milk. If someone isn't getting any saturated fats from other sources, this will offer some.  

Cons: Some would argue that too many of the saturated fats in coconut milk might present negative outcomes with cardiovascular health. It's likely less of an issue when someone's diet is made up of mostly unprocessed foods, and overall fat intake is balanced (equal amounts of unsaturated and saturated fats being consumed). 


Cashew milk

Pros: All tree nuts contain a mix of beneficial fats. But nothing notable beyond what you'd find in almond, walnut, or macadamia. 

Cons: There have been reports of human labor concerns related to cashew production overseas. The chemicals applied to cashews can be very toxic, especially to the laborers handling them. 


Macadamia milk

Pros: Can offer a creamy consistency/taste for baking. Good for low-fodmap eaters.  

Cons: Like other tree nuts, there's a steep environmental cost in production.  


Hemp milk

Pros: Hemp is one of my favorite crops, as it offers a lot of nutrition with not a lot of negative environmental repercussions. Good for low-fodmap eaters.

Cons: Tough to get from the U.S. due to legal barriers around hemp farming. 


Quinoa milk

Pros: Nothing stands out. To get the most nutrition from quinoa, you're probably better off eating it whole. 

Cons: American demand for whole quinoa has already led to some economic repercussions in areas of the world that produce quinoa as a staple. Putting quinoa in milk form might skew these economic repercussions even more. 


Peanut milk

Pros: Similar to soy, this offers a nice mix of nutrients, including fats and proteins. An environmentally efficient crop to produce, especially when grown on a sustainable farm. Good for low-fodmap eaters.  

Cons: Peanuts can contain molds, mostly depending on how they're grown/stored. 


Pea milk

Pros: Americans consume a staggeringly low amount of legumes (7 pounds per person per year), so I'm in favor of any method to boost intake, including pea milk. Consumption of legumes is linked to all sorts of beneficial health outcomes. Also, legumes tend to be an environmentally efficient crop to produce.  

Cons: Nothing I can think of when consumed in reasonable amounts.  


Plant-protein milk

Pros: Most obviously, it's a nice product for someone looking to get more protein in their diet. 

Cons: A bit more processed, which could have questionable long term health outcomes. 


Hazelnut milk

Pros: In the world of tree nuts, this one is less commonly consumed, so it offers a way to expand variety in ones diet. 

Cons: Like most other tree nut milks, it doesn't offer much in the way of substantial nutrients (unless made at home). And it has the environmental cost that comes along with tree nuts. 


Banana milk

Pros: A way to potentially use bananas that are about to go bad and be wasted. 

Cons: Bananas are one of the most popular fruits in America, so I'm not sure incorporating them into milk does us any favors in terms of expanding our dietary diversity. Plus, in milk form, it doesn't offer much in the way of nutrition.  


Walnut milk

Pros: Walnuts are one of the notable plant sources of omega-3 fats. A fat that most people aren't getting enough of. 

Cons: The environmental cost that comes with tree nut milks. 


Flax milk

Pros: Seeds are generally nutrient dense and environmentally efficient to produce. 

Cons: If someone is also eating flax, adding flax milk as well might be a bit much for the body on a daily basis, since flax is a rich source of lignans. 

Interview About Vegan Diets

I was recently interviewed about vegan diets. I wanted to share my full response here.

*Can a vegan diet can truly lend itself to a fit, active, and healthy lifestyle? What are the most important to things to keep in mind / be aware of to make that happen? 

There are many ways in which someone can build a dietary pattern that will support health and performance. A vegan diet is one way. 

Keep in mind that healthful dietary patterns have more in common than most people realize. Most healthful dietary patterns a) get people thinking about daily food choices; b) emphasize the consumption of more minimally processed foods; and c) ensure a greater nutrient intake. Together, this often leads to a healthier body size, more energy, improved sleep, a better mood, and so forth. A vegan dietary pattern can accomplish these same basic tenants. 

I guess the real question then becomes: If various dietary patterns can lead to improved personal health and performance, why bother with a more plant-based diet? A plant-based diet stands apart in two big ways. 1) How it supports environmental sustainability and 2) How it minimizes the high demand for animal products, which can allow more humane animal welfare practices to take precedence. 

A final note here, many people I come across aren't ready, willing, or able to eat a vegan diet for various reasons. And because of this, they feel like the only alternative is dietary status quo -- which usually includes animal products at most every meal. This is binary thinking and prevents us from exploring the middle ground (a more plant-based diet, rather than 100% vegan diet). So I would challenge people reading this to think about how you use dietary labels, and observe how these labels influence your decision making process around food.   

*What are the biggest nutrients people tend to fall short on when switching over to vegan?

Vegan diets can differ quite radically. Some vegan eaters emphasize minimally processed legumes, vegetables, and seeds. Some vegan eaters emphasize sugary cereals, non-dairy ice cream, and macaroons. And of course, some vegan eaters fall somewhere in-between. 

Generally speaking, the nutrients that vegan eaters will want to keep an eye on include:

Vitamin B12 - It's important that highly plant-based eaters use a vitamin B12 supplement regularly. Any form will do, including cyanocobalamin, methylcobalamin, or hydroxocobalamin. Not getting enough can result in neurological problems, inadequate red blood cell/white blood cell production, fatigue, lightheadedness, elevated heart rate, pale skin, depression, and mouth inflammation.

Vitamin D - While this vitamin can be obtained when the skin is exposed to adequate sunlight, it's probably not happening unless you live near the equator and spend most of your time outside with minimal clothing on. Thus, supplementation could be helpful, especially in the winter months (check levels with your doctor first). In terms of supplements, D3 seems to be a bit more effective than D2. 

Zinc - Zinc recommendations for the general population are based on diets lower in phytic acid. Highly plant-based diets are higher in phytic acid. Thus, highly plant-based eaters have zinc requirements that are just about doubled. Not getting enough can result in lowered immunity, hair loss, loss of appetite, dry eyes, and a lowered white blood cell count. Foods rich in zinc include quinoa, lentils, chickpeas, tofu, black beans, cashews, sesame seeds, sunflower seeds, almonds, peanuts, pumpkin seeds, mushrooms, spinach, cocoa powder, and dried apricots (among others). If getting enough zinc from food is problematic (best to assess this with a doctor or dietitian), find a supplement, any form will do, but zinc picolinate might be optimal. 

Iron - Absorption of iron varies tremendously based on body status and dietary source. Similar to zinc, plant-based eaters have iron requirements that are about 1.8 times higher (due to lower overall iron absorption). Folks who are physically active will require even more. Consuming foods rich in vitamin C along with iron rich foods can increase iron absorption. So before increasing iron rich foods, simply try increasing vitamin C rich foods along with iron. If you're a man or woman who eats a highly plant-based diet and donates blood, or if you're a pre-menopausal woman eating a plant-based diet, then an iron supplement can be very helpful. Not getting enough iron can result in spoon shaped nails, lowered immunity, fatigue, rapid heart rate, palpitations, rapid breathing on exertion, increased lactic acid production, irritation to corners of lips and tongue, gastritis, pica, and abnormal temperature regulation. Foods rich in iron include spinach, swiss chard, lentils, tempeh, chickpeas, pinto beans, green peas, tahini, almonds, pistachios, sunflower seeds, dried figs, and molasses (among others). 

Protein - Deep breath. :) First, I would encourage people not to classify plant foods as “complete” or “incomplete” proteins. This is antiquated categorization and really only useful when someone is relying on one or two foods to meet protein needs for an extended period of time. Here are three general principles for getting enough protein: 1) Eat enough food to support a healthy body size. 2) Eat a variety of food. 3) Eat at least 1 cup of cooked legumes per day. If someone likes numbers, plant-based eaters who are physically active should aim for around 1.4 grams or protein per kilogram of bodyweight.  

Omega-3 fats - While it's possible to get enough of these from plant sources, it really depends on the persons individual make up. Including an algae supplement with DHA/EPA might be helpful to ensure the minimum intake is being met. 

Finally, I have a theory (translation: not rooted in much science) that taurine and choline might also be an issue for certain plant-based eaters. I’m not sure if it’s a genetic thing or not, but it’s worth keeping these two on your radar as a plant-based eater.

*What are some mistakes you think athletes tend to make when going vegan?

Mistake: Eating a vegan diet as a way to lose weight fast, 'detox', or dramatically improve performance

Why it's a mistake: It likely won't lead to any real long-term behavior changes, and the next new dietary fad will derail your plan

What to do about it: Yes, a balanced vegan diet can support a healthy weight and athletic performance. But weight and performance are fleeting. Try getting clarity around your deeper values. And consider your "bigger-than-self" goals, such as how your food choices influence environmental sustainability, animal welfare, and farmworker welfare  

Mistake: Eating a bunch of ultra processed plant foods (e.g., vegan cookies) in place of minimally processed animal foods (e.g., hard boiled eggs)

Why it's a mistake: It likely doesn't support health, and will lead to feeling crummy and abandoning a plant-based diet

What to do about it: Emphasize minimally processed plant foods, including legumes, whole grains, vegetables, fruits, nuts and seeds. And figure out your minimal effective dose of animal products.

Mistake: Getting too hung up on purity/perfection when it comes to dietary labels/identity/tribalism 

Why it's a mistake: Trying to live a perfect vegan lifestyle (or paleo, or intermittent fasting, and so forth) can be exhausting. And really, it sets people up for burnout and/or frustration (and/or feelings of isolation from family/friends).

What to do about it: Don't be afraid to abandon dietary labeling/identity/tribalism, and instead find a way of eating that's based around your values/lifestyle. While it might not fit nicely under a clear label/identity/tribe, it will likely better support your long term well being   

Mistake: Eating a plant-based diet that's really low in fats or 100% raw

Why it's a mistake: It can lead to a diet that doesn't provide enough overall food/nutrients

What to do about it: Don't be scared by minimally processed foods that are higher in fats (e.g., avocados, nuts, seeds, etc.). And don't be scared by cooked foods.