Whether you are vegan or are just looking to reduce your consumption of meat, knowing which plant-based proteins have the highest amount of protein and how much of that protein is required will help you meet your nutritional goals.
Protein is duly named the building block of life and is crucial for:
- Build and repair muscles
- Skin and bone health
- Healthy brain function (neurotransmitter synthesis)
- Hormone synthesis (thyroid hormones, melatonin, insulin)
- Enzyme function
- Hemoglobin synthesis
- Immuno-protection (antibodies)
- Transporter functions (albumin and globulin in the blood)
- Stress mitigation (heat-shock proteins)
- Joint support (hyaluronic acid, chondroitin sulfate)
- Detoxification (phase II conjugation in liver)
- And much more
Plant Based Protein Requirements
It’s important to get the minimum amount of plant-based protein your body needs in order to perform its critical functions. Protein requirements do vary based on age, body size, sex, physiological state, and activity level. Those with certain health states such as wound healing will require more and those with kidney disease may need to reduce their protein intake. The guidelines below are for the generally healthy population.
The current estimated average requirement (EAR) for adults 19 years old and older is 0.66 grams of protein per kg of body weight per day. This is the minimum needed to perform body functions and achieve nitrogen balance in a healthy adult. The recommended daily allowance (RDA) for protein for adults is 0.8 grams of protein per kg of body weight per day, which is the protein requirement to maintain good health. For athletes, the American College of Sports Medicine recommends 1.2 to 1.4 grams per kg of body weight.
Some experts believe that it’s only necessary to get 0.8 grams of protein per kg of LEAN body mass (LBM). This is the total body weight minus body fat weight (body fat percentage). Calculate your lean body mass using a bioelectrical impedance (BIA) scale, calipers or a DEXA scan. You can also get an estimate for the average person using this tool. Either use your LBM or your actual weight in your calculation, depending on your preference.
To calculate your requirements, divide your weight (either LBM or actual) in pounds by 2.2 to get your weight in kilograms. Multiply your weight in kilograms by 0.66 and then multiply your weight in kilograms by 0.8. Aim for this range of protein consumption per day.
Protein requirement calculation examples:
120 pounds / 2.2 = 54.5 kg
54.5 kg x 0.66 grams/kg = 35.9 grams
54.5 kg x 0.8 grams/kg = 43.6 grams
The protein requirements for a 120-pound person are between 35.9 and 43.6 grams of per day.
If you ate one chicken breast, it supplies 46 grams of protein for the day. Any other protein sources that day would be excessive. It’s very easy to overeat protein on an animal-based diet.
For a plant-based diet, you can add another 0.2 to your protein requirements if you aren’t eating predominately complete plant-based protein sources. Here’s a calculation example:
120 pounds / 2.2 = 54.5 kg
54.5 kg x 0.86 grams/kg = 46.87 grams
54.5 kg x 1.0 grams/kg = 54.5 grams
The protein requirements for a 120-pound person (not eating high quality plant proteins) are between 46.8 and 54.5 grams per day.
Why is excessive protein a concern?
Protein requirements are often overstated. It’s also thought that protein is a neutral macronutrient, but that isn’t necessarily true especially when it comes to animal proteins. There is no benefit to your body above the recommended levels and excessive protein may impose a metabolic burden on the bones, kidney and liver as well as have other negative consequences to your health. While there are limited long-term studies on eating a high protein diet and it is a controversial subject, there are a few points to keep in mind.
Digestion of meat, fish, eggs, cheese and to a lesser extent some grains creates an acidic environment. This can also occur from soft drinks and the phosphoric acid. Excess acids need to be excreted in the urine but the body regulates the pH of the urine and will not allow it to get too acidic. The body must increase the pH by buffering it with bicarbonate and other substances found in fruits and vegetables. If there isn’t an ample supply of these foods in the diet, the buffering occurs at the expense of bone. When bone is catabolized to buffer the acid, it releases calcium, magnesium, and carbonate to act as a buffer. This decrease in bone density can lead to more serious conditions like bone fractures and osteoporosis.
All-cause mortality and cancer risk
Studies have found that middle-age people who ate foods rich in animal protein (milk, meat, cheese) were 75% more likely to die from any cause than those who ate a low-protein diet. They also showed a 4-fold increase in cancer and diabetes related deaths during the study period. The study defined a high-protein diet as 20% of daily calories from protein. A moderate protein diet is 10-19% and a low-protein diet was considered to be 10% of calories from protein.
HOWEVER, it also showed those 65 and older were less likely to die of cancer if they consumed more protein. Age is clearly a factor in determining adequate protein requirements for a healthy lifespan and protein should be increased once hitting this age group.
There is good news for plant-eaters here – the risk of cancer almost disappeared when the main source of protein came from plants such as legumes. Researchers suggest this may be because plant proteins do not stimulate growth hormones like animal meat does. These growth hormones, like IGF-1, may allow normal cells to become cancer-like cells and then help them grow.
Not Enough Protein
Not getting enough protein is also a concern as well. If you are experiencing any of these symptoms and you know your consumption is sporadic or very low, or you are on a poor quality plant-based diet, you may want to start tracking your diet in a food tracking app like Cronometer.
Symptoms of Protein Deficiency
- Decreased muscle mass
- Edema (water retention in legs, face or all over)
- Weakened immune system
- Brain fog and neuronal loss
- Thyroid issues
- Skin, hair and nail issues
- Fatty liver
- Increased bone fractures
- Stunted growth in children
Quality of Plant-Based Proteins
The body can produce all but 9 of the 22 amino acids that make up protein. The nine that the body cannot produce are called essential amino acids and must be obtained from the food we eat.
While quantity of protein is important, even just as important is quality of protein. Quality depends on the amino acid composition of the food source. A complete protein contains all the essential amino acids required by humans. These are mostly found in animal foods such as dairy, eggs, meat, fish and poultry, but certain plant foods are also a complete protein source. I’ll discuss those shortly. Incomplete proteins are found in most plant foods such as legumes, vegetables, nuts, seeds, and grains.
It’s important to plan out a plant-based diet very carefully to include a wide variety of food. If you tend to eat the same favorite foods all the time, you may be missing out on certain essential amino acids. When eating a plant-based diet, you need to pool the amino acids in all the different foods you eat to supply the required amount to form proteins for the functions listed above. However, it’s a misconception that you need to combine proteins in the same meal. Your body is fully capable of doing this on its own from several different meals.
Certain plant-based food groups have a limiting amino acid, meaning an amino acid that is present in the lowest quantity in the particular food. Generally, plant-based diets provide ample amounts of 7 of the 9 essential amino acids if the diet is varied.
The following amino acids may be limiting or low on a plant-based diet:
- Methionine in legumes
- Lysine and threonine (sometimes) in wheat, rice, corn and other grains
- Sometimes Tryptophan if not eating soy or wheat
These limiting essential amino acids can be found in the following plant foods:
Important for metabolism, detoxification, tissue growth, and absorption of zinc and selenium.
Plant-based foods rich in methionine: Soy, kidney beans, peanuts, great northern beans, brazil nuts, sesame seeds, watermelon seeds, pumpkin seeds, tahini, black walnuts, flaxseed, hemp seeds, chia seeds, peaches, banana, avocado, spirulina, chives, sweet peppers, parsley, leeks, mushrooms, soy, wheat, wild rice, oats, quinoa
Important for protein synthesis, hormone and enzyme production, energy production, immune function, collagen and elastin production, and absorption of calcium.
Plant-based foods rich in lysine: Sprouted lentils, chickpeas, pumpkin seeds, pistachios, cashews, sunflower seeds, black walnuts, almonds, tahini, brazil nuts, hemp seeds, chia seeds, watercress, spirulina, avocados, parsley, chives, sweet peppers, leeks, soy, almonds, cashews, dried apricots, lychee, avocado, wheat, quinoa, oat, amaranth, buckwheat, rye, wild rice, soba
Important for fat metabolism, immune function, for providing structural support for collagen and elastin, which is important for skin and connective tissue.
Plant-based foods rich in threonine: Soy, lupins, peanuts, kidney beans, fava beans, yellow beans, great northern beans, french beans, mung beans, chickpeas, pumpkin seeds, watermelon seeds, sunflower seeds, flaxseed, tahini, black walnuts, almonds, pistachios, cashews, spirulina, watercress, chives, sweet peppers, leeks, shiitake mushrooms, sun dried tomatoes, sprouted lentils, dried apricots, peaches, wheat germ, oats, amaranth, rice bran, rye, teff, buckwheat, soba, rye, wild rice
Important for function as a precursor to serotonin, which is a neurotransmitter that regulates sleep, mood and appetite. Also important for niacin production, pain management, sleep and mood.
Plant-based foods rich in tryptophan: Soy, peanuts, kidney beans, lupins, white beans, mung beans, chia seed, pumpkin seed, watermelon seeds, tahini, sunflower seeds, flaxseeds, cashews, pistachios, almonds, spirulina, parsley, chives, sweet pepper, leeks, turnip greens, dried apricots, raisins, avocados, oat bran, wheat germ, wheat, barley, soba, buckwheat, bulgur, buckwheat, wild rice
Best Sources of Plant-Based Protein
Protein requirements for vegans may increase depending on the quality of plant-based proteins they are consuming and if not properly prepared. See example #2 above on how to calculate protein requirements in this case. I’ve compiled a list of plant-based protein sources that are considered a complete protein and those that when consumed in a variety, can provide the essential amino acids to form a complete protein.
Complete Protein Sources
- Natto (organic non-GMO): 31 grams per 1 cup (if you can tolerate the taste and texture)
- Tempeh (organic non-GMO): 31 grams per 1 cup (think tempeh bacon)
- Hempeh (tempeh made from hemp seeds): 22 grams per 4 ounces
- Hemp hearts/seeds: 12.8 grams per 4 Tablespoons
- Hemp powder: 12 grams per 4 tablespoons
- Sacha inchi seed powder: 4 grams per 1 tablespoon
- Nutritional yeast: 5 grams per 1 tablespoon
- Spirulina: 4 grams per 1 tablespoon spirulina
Incomplete (but still good) Protein Sources
- Lentils: 18 grams per 1 cup
- Most Beans: 10-19 grams per 1 cup
- Almonds: 12 grams per ½ cup
- Walnuts: 10 grams per ½ cup
- Green peas: 8.5 grams per 1 cup cooked
- Peanuts: 7 grams in 1 ounce
- Almond butter: 6 grams per ¼ cup
- Cauliflower: 5 grams in 1 small head
- Brazil nuts: 4 grams per 6 nuts
- Artichokes: 4 grams per 1 artichoke
- Maca powder: 3 grams per 1 tablespoon
- Spinach: 3 grams per ½ cup cooked
- Mushrooms: 3 grams per 1 cup
- Asparagus: 2.9 grams per 1 cup
- Avocado: 2 grams per ½ avocado
- Broccoli: 2 grams per ½ cup cooked
- Brussels sprouts: 3 grams per 1 cup
- Chia seeds: 2 grams per 1 tablespoon
- Flaxseed: 2 grams per 1 tablespoon
Plant-Based Protein Digestibility and Anti-Nutrients
Another factor that affects levels of protein in the body is the digestibility of the protein source. Animal protein is generally found to be 90% to 99% digestible, whereas plant proteins can range from 70% to 90% digestible. This may be due to the anti-nutrients found in plants such as glucosinolates, trypsin inhibitors, hemagglutinins, tannins, phytates, and gossypol. These anti-nutrients can block the absorption of protein and make it less bioavailable. However, many of these anti-nutrient factors can be lessened with proper preparation techniques like soaking, fermenting, and sprouting.
I love making a warm bowl of dal with sprouted lentils or snacking on sprouted pumpkin seeds. These are easy to find online and at some stores. Otherwise, most other legumes and sometimes nuts and seeds should be soaked and sprouted at home. This can be a little time consuming, but it’s definitely more economical buying a bag of dried beans than canned beans. This one change is worth the investment of your time.
Recommended Plant-based Protein Powders
Getting all the plant protein you need on a plant-based diet is not difficult if you plan properly and get your protein from a variety of plant-based foods. If you are still struggling getting adequate amounts of plant-based protein in your diet, I recommend adding in a pea and/or hemp protein powder. These can provide a complete amino acid profile and can be easily added to a breakfast smoothie every morning. These pea protein powders offer a vegan source that has high bio-availability and digestibility.
Click any product above to view pricing and to purchase. You will be asked to create an account with my online supplement dispensary.
Plant Powered Athletes
If you need a little inspiration or still wondering if you can get all the protein you need on a plant-based diet, just look to these plant-powered athletes for proof.
- Venus Williams – tennis player
- Griff Whalen – Oakland Raiders, wide receiver
- Tom Brady – New England Patriots quarterback
- 11 of the Tennessee Titans
- Barney du Plessis– body builder, Mr. Universe 2014
- Brendan Brazier – Ironman Triathlete and 50km Ultra Marathon Champion
- Carl Lewis – gold medal track and field
- Nate Diaz – UFC mixed martial artist
Key Points on Plant-Based Protein Sources
- For adults, the recommended daily amount of protein is between 0.66 and 0.8 grams of per kg of body weight or kg of LEAN body weight
- High animal protein, has been linked to increased rates of cancer, diabetes and overall mortality while vegan sources have not
- Eat a lower protein diet during middle-age, followed by a moderate protein diet starting around age 65 in order to optimize your health-span
- Include as many complete plant-based protein foods as possible. These include hemp, soy (if tolerated) and nutritional yeast. Fill in the rest with protein plant-based foods like nuts, seeds, legumes, brown rice, and other whole grains.
- If eating legumes, try to prepare them properly by soaking and sprouting to avoid anti-nutrients which decrease bio-availability
- Try adding one of the listed pea protein powders to your morning smoothie for an easy way to get a complete plant protein in your diet.
Sign up for a nutrition consultation if you are interested in more personalized help with a plant-based diet tailored to your specific health status.
The above statements have not been evaluated by the Food and Drug Administration. The products mentioned are not intended to diagnose, treat, cure or prevent any disease. Check with your doctor or nutritionist before starting a new supplement program.
Levine ME, Suarez JA, Brandhorst S, et al. Low protein intake is associated with a major reduction in IGF-1, cancer, and overall mortality in the 65 and younger but not older population. Cell Metab. 2014;19(3):407-17.
Delimaris I. Adverse Effects Associated with Protein Intake above the Recommended Dietary Allowance for Adults. ISRN Nutr. 2013;2013:126929. Published 2013 Jul 18. doi:10.5402/2013/126929
Lynch H, Johnston C, Wharton C. Plant-Based Diets: Considerations for Environmental Impact, Protein Quality, and Exercise Performance. Nutrients. 2018;10(12):1841. Published 2018 Dec 1. doi:10.3390/nu10121841