Updated: Mar 21
If someone you were talking to was concerned about their protein intake if they moved to a plant-based diet (because they heard that plant-based protein isn't as "good" as an animal-based diet), what would you say to them?
If the person asked about how much protein they should be eating in a day, what would you say to them?
What are some examples of plant-based meals that would meet your optimal protein requirements?
Now that I've been on a plant-based diet for almost a decade, I'm tempted to cringe at those who question the adequacy of my protein intake. But I don't, because I remember having those same concerns at the beginning of my transition. As a multi-sport athlete, I also grew up in the protein-meat-gym culture and those misconceptions about protein are very difficult to reverse. I transitioned for health reasons, but I was still concerned that my athletic performance would be negatively impacted by my new plant-based diet. That's why I paid special attention to learning about what makes plant-protein different than animal protein and how to make sure I was getting enough. Turns out that meeting protein requirements is easier than most think.
Protein Quality: Plant-Based Versus Animal-Based Protein
What makes a protein source good or bad? Are there higher quality proteins out there? When considering protein sources, are your goals related to health, weight loss or athletic performance? Turns out that there are many different nuances to take into account when considering the "quality" and "quantity" of protein required.
To understand protein quality, one must understand what protein is. Fortunately, it isn't too complicated. Compare a protein molecule to a chain made out of individual links, or imagine a necklace made out of individual beads. Each link or bead is an amino acid. There are 20 different amino acids, with 11 of them being non-essential, meaning that we can synthesize them from scratch, and 9 of them that are considered essential, meaning that they must be obtained through food since our body doesn't have the biochemical machinery to make them. After passing through the stomach, these links, or beads, are separated from each other into their individual amino acids (or shorter dipeptide or tripeptide chains). At this stage, the body has no way of knowing whether an amino acid molecule is of plant or animal origin, and our body will use these individual amino acids in variable combinations and lengths to create new protein. Once protein is digested into its individual amino acids, plant protein is indistinguishable from animal protein. But determining a protein source's quality is not that simple. We don't just eat macronutrients, we eat food, and food comes as a package containing many other different macro and micronutrients that all independently play a role in how we digest, absorb and synthesize new protein. The whole package will determine a protein's quality.
Protein quality is determined by many factors, including: 1) the food matrix in which it's packaged, 2) its digestibility, 3) its amino acid profile and 4) your goals. These can range from improving health, to weight loss and even up to muscle protein synthesis for improved athletic performance.
We don't eat macros, we eat food, and food comes as a packaged deal. Protein quality can also be determined by the health impacts of the other macro or micronutrients that are consumed within the protein source. Typically, animal protein comes packaged with saturated and trans fats, as well as cholesterol. It also leads to the production of TMAO through gut fermentation, and contains no fiber to feed our gut microbiota. Although animal protein could be argued to contain a slightly more favorable amino acid profile or easily digestible "complete" protein when compared to some sources of plant protein, this can be easily compensated through strategies outlined below. Because of its health promoting food matrix, it's no surprise that studies have shown that reduced rates of chronic disease are seen in those that swap animal protein for plant sources, since these contain minimal saturated fat (except for coconut and some tropical oils), zero cholesterol, zero trans fat and tons of fiber, antioxidants and phytochemicals.
Although the food matrix of plant protein sources helps reduce chronic disease rates, the high fiber content, among other factors, of the plant matrix makes them slightly more difficult to break down. As a result, slightly less protein is available for absorption in certain plant sources of protein. Although digestibility doesn't make a protein source inherently good or bad, it does significantly impact absorption and is why certain experts still recommend that those who rely solely on plant sources of protein consider increasing their protein intakes by 10% to compensate for the reduced digestibility and absorption. It's important to point out that many plant protein isolates have similar digestibility and absorption rates as animal protein, as does high quality sources like tofu and tempeh, that are considered complete proteins that are highly digestible.
Amino Acid Profile
When comparing protein qualities between animal and plant sources, proponents of omnivorous diets will often cite the "completeness" of animal protein. This refers to the amino acid profile of a particular protein source. Animal protein is a complete protein, meaning that it contains all essential amino acids in sufficient quantities to promote protein synthesis. Incomplete protein, often used to describe plant sources of protein, is often mistakenly confused as being inadequate. All plant sources of protein contain all types of amino acids, but not in sufficient quantity to promote muscle synthesis when used as the only source of protein in one's diet. Lucky for us that the body can use amino acids consumed throughout the day and combine them to do do the "completing" for us. As stated in a study on protein and amino acids in vegetarian diets by Mariotti and Gardner in November 2019: "the body of evidence so far does not show a difference large enough to result in risk of insufficient amino acid absorption for vegetarian and plant-based diets". The only situation that could pose a risk in terms of amino acid deficiency is one where there is lack of variety of plant foods in one's diet, or when people aren't meeting their calorie requirements.
Your Goals And How They Can Impact Protein Sources
If your goal is health, then the health promoting food matrix of plant protein sources is the evidence based way to go. If you're looking for weight loss, the lower calorie density of plant sources of protein, when compared to animal-based sources, is a great way to manage body weight without compromising health or quality of life and without restricting food intake. If you're looking to maximize muscle protein synthesis, plant sources of protein can get you there, although this might require some additional time for proper planning. Since animal protein sources are all complete sources of protein, single food meals could theoretically meet amino acid requirements. That being said, the lack of variety would significantly impact the adequacy of micronutrient intake. This would greatly impact health outcomes. If you're eating sufficient calories from a variety of plant foods, the evidence shows that you'll be easily meeting overall protein and amino acid requirements and getting healthier in the process.
Protein Requirements: How Much Is Enough?
Despite an abundance of peer reviewed research confirming that vegetarians and vegans get adequate amounts of protein, there is still pervasive misconceptions that somehow they fall short of their daily requirements. In their review of dietary protein intakes in almost 7500 people, Mariotti and Gardner conclude: "Although uncertainties remain regarding protein requirements, the data in adult vegetarians indicate that classic vegetarian diets supply more than adequate protein and amino acids".
Recommended Daily Allowance (RDA)
In order to meet the nutrient requirements of nearly all healthy individuals, a RDA for protein has been set at 0.8 grams of protein per kilogram of lean body mass. The RDA ensures that almost everyone hits nutrient needs, but it can then be finely tuned to optimal levels in specific populations who might have greater requirements. For the average person of average weight, 50 grams per day is enough to meet your protein goals. For optimal performance and maintenance of muscle mass, it is recommended that athletes bump up their protein intakes to 1.4-2.0 g/kg/day, depending on the type and intensity of their workouts. Special considerations can also be made for women who are pregnant, lactating, or for the elderly, who might require minor adjustments in protein goals.
Meeting My Protein Requirements
As a 40 year old plant-based athlete looking to maintain muscle mass and accelerate recovery between workouts, some thoughts have to go into meal planning. I personally aim for 1.6 grams of protein per kg per day, although I haven't logged in my protein intake for years now. At the beginning of my transition, using smart phone apps like My Fitness Pal or Cronometer did help a lot in determining if my protein intake, and specifically my leucine intake, was adequate. Adequate leucine intake is very important for those looking to maximize muscle mass maintenance and recovery between workouts. I weigh 70 kg and try to aim for a daily intake of 110 grams of protein (which makes the 1.6 g/kg). Considering that I eat 3 meals, two snacks and a recovery smoothie after my workouts, I can achieve my protein goals without much effort. Protein is best consumed throughout the day, divided in equal "doses" instead of being consumed all at once, if muscle protein synthesis and muscle mass maintenance is your goal.
To illustrate how I reach my protein goals, I wanted to use my daily go-to breakfast and breakdown its nutrient content. Typically, on weekday mornings, I have a bowl of sprouted oats, cooked in soy milk. I then mix in cinnamon, chia and hemp seeds, then top it off with berries and whole grain granola. When I feel like I can benefit from added protein, I sometimes mix in a scoop of my favorite blended plant-based protein powder. You'll notice on the photos below that in one meal, I almost get 40 grams of protein. The app sets a default requirement of 144 grams per day for me, but that's more than I really need. With the 37 grams of protein included in my breakfast, I get more than 33% of my daily requirements, and I still have 3-4 more meals to go. Although I didn't add the other nutrients in the attached photos, with this breakfast alone, I also got 30 grams of fiber, 10 mg of iron, 500 mg of calcium, 25% of my daily zinc requirements and 125% of my B12 requirements.
Other examples of meals that I love to eat include scrambled tofu, brown rice and quinoa mixed with beans and veggies, and chickpea chana masala, my personal favorite! Whatever the plant-based meal, I routinely throw in nuts, seeds, nutritional yeast or frozen vegetables in there in order to boost plant variety, amino acid profile and nutrient diversity!
My Plant-Based Prescription
Rest assured that when people defend their dietary patterns with claims of animal protein being better, you can rely on an abundance of scientific research painting a very different picture. People love hearing good news about their bad habits, and all you can eat bacon sounds sexier than a broccoli buffet. It's normal that people disregard plant foods as adequate sources of protein when millions of dollars are invested in marketing meat and dairy as the gold standards of protein. When people worry about insufficient protein intake on vegan or vegetarians diets, show them the studies cited below. They clearly prove that even vegans that aren't necessarily seeking out plant-based protein sources are still hitting their protein goals. And when they look confused and ask you "what do you eat in a day", be proud to show them that your plant-based recipes aren't these restrictive or mystical meals made with rare and hard to find ingredients, but simple meals made with legumes, whole grains, fruits, veggies, nuts and seeds. Plant-based meals can be super healthy, are associated with reduced rates of chronic disease, reduced all-cause mortality and can be made into delicious recipes that any foodie can appreciate! Once the initial learning and planning phases are complete, transitioning to a plant-based diet will likely be the greatest investment you've ever made in your health and the health of our planet.
Check out my website plantbaseddrjules.com and look for the “How To” section in the menu. There, you’ll find tips and tricks that helped me on my journey towards a plant-predominant diet. Everything there is completely free, no catches! If you're looking for healthy high protein plant-based recipes, check out plantbaseddrjules.com and download my free recipe eBook!
Look for me on the socials, @plantbased_dr_jules on Instagram and go like my Facebook Page, Plant-based Dr. Jules. If you’re looking for some fitness motivation and are curious to see what a plant-based athlete can accomplish, follow me, @maritimeninja, on my fitness account on Instagram or check out my fitness group on Facebook, called Maritime Ninja Warrior.
Thanks so much for reading!
Plant-Based Dr. Jules 💚🌱
Mariotti, F., & Gardner, C. D. (2019). Dietary Protein and Amino Acids in Vegetarian Diets—A Review. Nutrients, 11(11). https://doi.org/10.3390/nu11112661
Nutrient profiles of vegetarian and nonvegetarian dietary patterns. J. Acad. Nutr. Diet., v.113, p.1610, 2013, Rizzo N.S. et al.
Intake of total, animal and plant proteins, and their food sources in 10 countries in the European prospective investigation into cancer and nutrition. Eur. J. Clin. Nutr., v.63, p.S16, 2009, Halkjaer J. et al. doi: 10.1038/ejcn.2009.73
Plant protein intake and dietary diversity are independently associated with nutrient adequacy in French adults. J. Nutr., v.146, p.2351, 2016, Bianchi C.M. et al. doi: 10.3945/jn.116.236869
Plasma concentrations and intakes of amino acids in male meat-eaters, fish-eaters, vegetarians and vegans: A cross-sectional analysis in the EPIC-Oxford cohort. Eur. J. Clin. Nutr., v.70, p.306, 2016, Schmidt J.A. et al. doi: 10.1038/ejcn.2015.144
Comparison of nutritional quality of the vegan, vegetarian, semi-vegetarian, pesco-vegetarian and omnivorous diet. Nutrients, v.6, p.1318, 2014, Clarys P. et al.
Protein quality evaluation twenty years after the introduction of the protein digestibility corrected amino acid score method. Br. J. Nutr., v.108, p.S183, 2012, Boye J. et al.
Plant protein, animal protein, and protein quality, Vegetarian and Plant-Based Diets in Health and Disease Prevention, 2017 , Academic Press , Mariotti F. et al.