How To Eat A Plant-Based Diet And Not Die Of Malnutrition
Written by Calvin Sun
Coach Nick and I had a discussion recently about a client he’s counseling who doesn’t eat meat. I understand people have different reasons for avoiding meat. Some people avoid it for moral and philosophical reasons, such as religious beliefs, animal rights, and even environmental reasons. There are others who believe avoiding meat is healthier. Sometimes, this belief is fueled by the myth that saturated fat is bad for you. While science has refuted this myth in recent years [1,2,3], the dogma seems to persist in many circles. If you have chosen to eat a plant-based diet, understand that I’m not here to convert you. I respect your beliefs and reasons for choosing to do so. Proselytism is not part of my job description. Education, however, is a core component of my job. My goal is to provide you with the best information possible so that you can make informed, educated decisions about your health and fitness.
We want you to be healthy and improve your performance in the gym as well as your everyday life. We like a Paleo/Primal as a nutritional framework because we truly believe that it is the optimal way to maximize both health and performance. If you aren’t familiar, I can briefly summarize the diet as high-quality protein, lots of nutrient-dense vegetables, healthy fats, some fruit, a little starch and no sugar. Vegetarian staples such as legumes, grains, seitan, and soy are no-no’s in a Paleo/Primal diet. These foods are not recommended due to the fact that they contain anti-nutrients such as phytates , lectins , and gluten [7,8] and can cause a variety of health issues [4,5,6,7,8]. Paleo is not about eating buckets of bacon and slabs of cow, as some people might have you believe. Our nutritional approach is based on food quality. While animal protein is a part of the diet, a large variety of plant-based foods, such as leafy green vegetables, fruits, nuts, seeds, and healthy fats, must be included.
Plant-based diets must contain a wide variety of vegetables as well. I’ve noticed that some plant-based eaters like to stick to legumes, grains, processed foods and little to no vegetables or fruits. Vegetarian and vegan diets are not inherently healthy. Your plant-based diet should not exclusively consist of deep-fried falafel, bowls of pasta, soy-based pseudo-meats, and a glass of wine or two. At least, not if you want to look good and feel good.
My point is that there is a common ground for both Paleo and plant-based diets: Food quality should matter to you, nutrient-dense vegetables should be consumed at every meal, food should be minimally processed, and you should strive for a good balance of macronutrients as well as micronutrients. Assuming you are set on eating a plant-based diet, we thought it might be a good idea to provide some nutritional guidelines to ensure you can get the most out of your training.
One of the most common questions about plant-based diets is protein intake. There are two common issues with plant-based diets: incomplete amino acid profiles and inadequate protein to support exercise and recovery. Essential amino acids cannot be synthesized in the human body, yet they are required for protein synthesis and recovery from exercise [9,10,11]. You must consume essential amino acids through food or supplements. Many plant-based protein sources have incomplete amino acid profiles or are deficient in essential amino acids. Eating a variety of whole foods will help prevent developing a deficiency. Protein is also essential for weight loss, repairing and building muscle tissue, formation of enzymes, as well as several other functions in your body. Make sure you are getting enough protein.
Less active but otherwise healthy adults: Approximately 0.4 grams per pound of body weight. For example, for an adult that weighs 150 lbs, you’ll need about 60 grams a day to prevent protein deficiency.
Adults engaging in high-intensity exercise: 0.6-1.0 grams per pound of body weight. For the same 150 lb adult that exercises regularly, 90 to 150 grams of protein a day is necessary. You’ll want to be at the upper end of the spectrum if you are training 3 to 5 times a week, lifting, and regularly participating in high-intensity conditioning workouts.
Pescatarians and Lacto-ovo-vegetarians: Eggs and fish are great sources of protein. They both have complete amino acid profiles and fit within both Paleo as well as semi-vegetarian diets. Be sure to buy the highest quality protein possible. Omega-3, cage-free eggs and wild-caught fish are great choices. Protein powder can also be a useful supplement for post-workout shakes. Three eggs contain about 20 grams of protein, an 8-ounce serving of salmon has about 45 grams of protein, and a scoop of whey protein powder is about 25 grams of protein. That’s 90 grams of protein if you ate just those three items.
Vegans: No animal products at all make it harder to eat complete and adequate protein. While it’s possible, you will likely have to venture outside of the Paleo framework to get adequate intake. Start with eating plenty of nutrient-dense plant foods like broccoli, spinach, cucumber, celery, squash, asparagus, seaweed, hemp seeds, pumpkin seeds, walnuts, and almonds. Legumes, while not Paleo, will likely be a part of a vegan diet. Peas, edamame, lentils, kidney beans, and tofu are popular options. Legumes like soy are a common staple in plant-based diets because of their protein content but they’re not perfect. They contain phytic acid, which binds to minerals like calcium, magnesium, and zinc so excess consumption can cause mineral deficiencies [5,12,13]. Also, consider supplementing with a plant-based protein powder. There are blended protein powders that combine hemp, rice, and pea protein to provide a complete amino acid profile.
Potential Nutrient Deficiencies
Vitamin B-12: This vitamin is essential in cellular metabolism and plays a vital role in energy production. B-12 is typically only found in animal foods and deficiencies of B-12 in vegetarians are well documented [14,15]. If you are eating a plant-based diet, you will need to supplement to ensure you don’t develop a deficiency.
Iodine: This trace element is essential for proper thyroid function. The thyroid plays a key role in regulating metabolism and studies have found that vegetarians are at risk for iodine deficiency . Iodized salt and certain sea-based salts are good sources of iodine. You can also consume iodine-rich foods, such as seaweed, to prevent deficiency.
Calcium: This mineral is essential for more than just bone health. Calcium ions play an important role in cellular physiology as well as muscle contractions. As we discussed earlier, some foods in plant-based diets contain phytic acid or phytates [5,12,13] and can inhibit absorption of minerals like calcium. Ensure you are eating plenty of green leafy vegetables, reduce intake of soy and other phytate-rich foods, and consider supplementing if necessary.
Omega-3 fats: These fatty acids are essential for health. Studies have found omega-3 consumption to provide a variety of health benefits including preventing heart disease, reducing inflammation, and even improving cognitive function [17,18,19]. If you are a vegetarian, supplement with 2 to 4 grams of fish oil every day. If you are a vegan, there are algae-based omega-3 supplements available. These will provide omega-3 fats in the eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) forms, which have been proven to have the greatest health benefits. Flax seed oil is not ideal as it only contains omega-3’s in the form of alpha-linoleic acid (ALA). Your body can convert ALA to EPA and DHA but the yield is very low, about 5% .
Vitamin D: Critical for optimal health and nearly everyone is deficient . Low levels of vitamin D are associated with cancers, inflammation, chronic illness and heart disease . Vitamin D deficiency can also cause sleep issues . Sunlight is the best way to get vitamin D, but if you unable to get some sunshine, consider taking supplemental vitamin D.
Our Guidelines For Eating A Plant-Based Diet
1. Eat plenty of nutrient-dense vegetables at every meal.
2. Eat a wide variety of organic, unprocessed foods.
3. Eat protein with every meal.
4. If you choose to eat grains, pick minimally processed grains like quinoa, amaranth, and oats.
5. If you must eat legumes, use lectin-reducing and phytate-reducing methods, like sprouting or soaking to minimize negative health effects.
6. Keep soy intake to one serving a day, if at all.
7. Avoid processed foods like crackers, chips, and other snack foods.
8. Avoid gluten as much as possible.
9. If you are trying to lose fat, avoid juices, sodas, alcohol, and sweetened beverages.
10. Drink plenty of water, though you can have some green tea or black coffee if you need some caffeine.
11. Supplement with Vitamin B-12 and Omega-3 fatty acids. Get some sunshine for Vitamin D or consider supplementing.
There are actually many similarities between healthy eating habits, whether Paleo or plant-based. The primary difference between the two is the source of your protein. If you are a semi-vegetarian, you should have no problem following the Paleo framework to maximize health without any compromises. Vegans will most likely have to venture outside of the framework of Paleo to get adequate protein. If you have chosen vegetarianism or veganism solely based on the desire to be healthier, I would encourage you to examine the effects of gluten, grains, and dairy on the human body with an open-mind. If your choice is firmly rooted in moral, religious, and philosophical reasons, know that we, as professional coaches, completely respect your beliefs and are more than happy to help you search for solutions that allow you to be as healthy and fit as possible.
1. Patty W Siri-Tarino, Qi Sun, Frank B Hu, and Ronald M Krauss. Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. Am J Clin Nutr March 2010 vol. 91 no. 3 535-546.
2. Tatiana F. Galvao, Bethany H. Brown, Peter A. Hecker, Kelly A. O’Connell1, Karen M. O’Shea1, Hani N. Sabbah, Sharad Rastogi, Caroline Daneault, Christine Des Rosiers and William C. Stanley. High intake of saturated fat, but not polyunsaturated fat, improves survival in heart failure despite persistent mitochondrial defects. Cardiovasc Res (2012) 93 (1): 24-32.
3. Patty W Siri-Tarino, Qi Sun, Frank B Hu, and Ronald M Krauss. Saturated fat, carbohydrate, and cardiovascular disease. Am J Clin Nutr March 2010 vol. 91 no. 3 502-509.
4. Rachel C. Masters, Angela D. Liese, Steven M. Haffner, Lynne E. Wagenknecht, and Anthony J. Hanley. Whole and Refined Grain Intakes Are Related to Inflammatory Protein Concentrations in Human Plasma. J Nutr. 2010 March; 140(3): 587–594.
5. John G. Reinhold, A. Lahimgarzadeh, Khosrow Nasr, Hadi Hedayati. Effects of purified phytate and phytate-rich bread upon metabolism of zinc, calcium, phosphorus, and nitrogen in man. The Lancet, Volume 301, Issue 7798, 10 February 1973, Pages 283–288.
6. Pusztai, A. and Bardocz, S. Biological Effects of Plant Lectins on the Gastrointestinal Tract:Metabolic Consequences and Applications. Trends in glycoscience and glycotechnology, 1996, 8:149-165.
7. Jessica R Biesiekierski, et al. Gluten Causes Gastrointestinal Symptoms in Subjects Without Celiac Disease: A Double-Blind Randomized Placebo-Controlled Trial. Am J Gastroenterol 2011; 106:508–514; doi:10.1038/ajg.2010.487.
8. Mervi Viljamaa, Katri Kaukinen, Heini Huhtala, Sinikka Kyrönpalo, Martin Rasmussen and Pekka Collin. Coeliac Disease, autoimmune diseases and gluten exposure. 2005, Vol. 40, No. 4 , Pages 437-443.
9. Elisabet Børsheim , Kevin D. Tipton, Steven E. Wolf, Robert R. Wolfe. Essential amino acids and muscle protein recovery from resistance exercise. Am J of Phys – Endocrinology and Metabolism, Published 1 October 2002, Vol. 283, no. E648-E657.
10. Elena Volpi, Hisamine Kobayashi, Melinda Sheffield-Moore, Bettina Mittendorfer, and Robert R Wolfe. Essential amino acids are primarily responsible for the amino acid stimulation of muscle protein anabolism in healthy elderly adults. Am J Clin Nutr August 2003 vol. 78 no. 2 250-258.
11. Christos S. Katsanos , Hisamine Kobayashi , Melinda Sheffield-Moore , Asle Aarsland , Robert R. Wolfe. A high proportion of leucine is required for optimal stimulation of the rate of muscle protein synthesis by essential amino acids in the elderly. Am J of Phys – Endocrinology and Metabolism. Published 1 August 2006, Vol. 291, no. E381-E387.
12. Ann-Sofie Sandberg. Bioavailability of minerals in legumes. British Journal of Nutrition, Volume 88, Supplement S3, December 2002, pp 281-285.
13. R F Hurrell, M A Juillerat, M B Reddy, S R Lynch, S A Dassenko, and J D Cook. Soy protein, phytate, and iron absorption in humans. Am J Clin Nutr September 1992 vol. 56 no. 3 573-578.
14. M. Hellebostad, T. Markestad, K. Seeger Halvorsen. Vitamin D Deficiency Rickets and Vitamin B12 Deficiency in Vegetarian Children. Acta Paediatrica, Volume 74, Issue 2, pages 191–195, March 1985.
15. Weiss, Rachel; Fogelman, Yacov; Bennett, Michael. Severe Vitamin B12 Deficiency in an Infant Associated With a Maternal Deficiency and a Strict Vegetarian Diet. Journal of Pediatric Hematology/Oncology, April 2004 – Volume 26 – Issue 4 – pp 270-271.
16. Thomas Remera, Annette Neuberta and Friedrich Manza. Increased risk of iodine deficiency with vegetarian nutrition. British Journal of Nutrition, Volume 81, Issue 01, January 1999, pp 45-49.
17. A.P Simopoulos. The importance of the ratio of omega-6/omega-3 essential fatty acids. Biomedicine & Pharmacotherapy, Volume 56, Issue 8, October 2002, Pages 365–379.
18. Artemis P. Simopoulos. The Importance of the Omega-6/Omega-3 Fatty Acid Ratio in Cardiovascular Disease and Other Chronic Diseases. Exp Biol Med (Maywood) June 2008 vol. 233 no. 6 674-688.
19. Klára Kitajka, Andrew J. Sinclair, Richard S. Weisinger, Harrison S. Weisinger, Michael Mathai, Anura P. Jayasooriya, John E. Halver, and László G. Puskás. Effects of dietary omega-3 polyunsaturated fatty acids on brain gene expression. PNAS, July 27, 2004, vol. 101 no. 30.
20. Gerster H. Can adults adequately convert alpha-linolenic acid (18:3n-3) to eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3)?. Int J Vitam Nutr Res. 1998;68(3):159-73.
21. Prentice, A. Vitamin D deficiency: a global perspective. Nutr Rev. 2008 Oct; 66 (10 Suppl 2): S153-64.
22. Michael F. Holick, M.D., Ph.D. Vitamin D Deficiency. N Engl J Med 2007; 357:266-281.
23. Gominak SC, Stumpf WE. The world epidemic of sleep disorders is linked to vitamin D deficiency. Med Hypotheses. 2012 Aug;79(2):132-5.