Introduction
Veganism is making a significant impact in the world of sports. Athletes are choosing to replace beef with beets, driven by the belief that this shift can enhance their overall health, performance, and recovery. Informally, numerous vegan athletes attest to reaching their peak performance. Examples include tennis player Venus Williams, boxer David Haye, Formula-1 driver Lewis Hamilton, weightlifter Kendrick Ferris, footballer Jermain Defoe, and ultra-marathon runner Scott Jurek—all of whom have embraced veganism and are flourishing. While research on the influence of veganism on athletic performance has been limited, a recent review has emerged to establish practical recommendations for vegan athletes, drawing insights from existing literature in other academic domains.
Who Are Vegans?
Vegans are individuals who choose a lifestyle that excludes all animal products from their diet and often extends to other aspects of their lives, avoiding the use of animal-derived products such as clothing and cosmetics. They primarily consume plant-based foods, emphasizing fruits, vegetables, grains, nuts, seeds, and legumes, while abstaining from animal-based foods like meat, dairy, eggs, and honey. This choice is often motivated by ethical, environmental, and health reasons.
What Are the Nutritional Considerations for Vegan Athletes?
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Energy Intake: Weight loss has been observed among athletes making the switch to a vegan diet. The reason behind this phenomenon is the nature of plant-based foods, which tend to possess a high volume and occupy substantial space in the stomach while containing fewer calories. Moreover, these foods are richer in dietary fiber, resulting in increased and earlier feelings of fullness. To counter this, vegan athletes should prioritize the consumption of calorie-dense options like nuts, seeds, trail mixes, hummus, olive oil, and high-quality granola bars. This approach becomes crucial in ensuring adequate energy intake and preventing undesirable weight loss.
Insufficient energy intake among athletes might amplify their susceptibility to immune suppression, potentially culminating in illnesses that necessitate breaks from training and competitions.
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Proteins: Plant-based protein sources do not have all the important building blocks called amino acids that animal-based proteins do. To get a full set of these amino acids, it is best to eat a mix of different plant-based protein sources each day. For example, having grains with beans or lentils or nuts/seeds with grains can help create a complete set of amino acids.
Plant proteins are a bit harder for the body to break down compared to animal proteins. So, I usually recommend that vegan athletes aim for at least 1.8 grams of plant-based protein per kilogram of their body weight each day. The general advice is to get between 1.4 to 2.0 grams per kilogram per day and even more (over 2 grams per kilogram per day) if they are trying to lose weight. Some good sources of plant-based protein are foods like seitan, tofu, tempeh, pumpkin seeds, lentils, beans, oats, and quinoa (which has all the amino acids).
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Fat and Omega-3 Fatty Acids: Vegan diets often have less total and saturated fats but more omega-6 fats. This aligns with reported health benefits. High-fat diets are now seen positively, aiding exercise and body composition. Athletes should target 0.5 tp 1.5 g/kg daily fat intake. A balanced omega-6 to omega-3 ratio (1:1 to 4:1) is vital, avoiding excessive omega-6 from refined oils. Vegan athletes lack marine-sourced omega-3s; alternatives include flaxseeds, chia seeds, algae, and seaweed, aiming for 1 to 2 g/day omega-3 intake with a 2:1 EPA: DHA ratio.
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Vitamin B12: Meeting all essential needs through a vegan diet without supplementation is not achievable, given that vitamin B12 is exclusively present in animal sources. Fortified options like nutritional yeast, plant-based milk, and fortified breakfast cereals are available. Yet, relying heavily on processed cereals is less advisable due to their distance from natural sources. In order to ensure safety, a vitamin B12 supplement (up to 6 ug/day) is recommended, with no adverse effects when surpassing daily limits (1,17). Monitoring vitamin B12 levels is crucial due to potential absorption difficulties in vegans; prolonged deficiency could lead to permanent nerve damage.
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Iron: Plant-based foods tend to provide iron that is less easily absorbed, which can lead to lower iron levels. While adaptations in the gut can enhance absorption, it is advisable for vegans to increase their iron intake by 80 percent (to 14 mg/day for men and 33 mg/day for women). For vegan athletes, it is crucial to limit the consumption of dietary inhibitors like phytic acid and tannins found in coffee, tea, and cocoa, particularly during meals. To improve iron absorption, incorporating vitamin C-rich foods alongside iron-rich sources such as legumes, grains, nuts, seeds, greens, and fortified foods is important.
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Zinc: Zinc is found in various plant-based sources like pumpkin seeds, nuts, oats, nutritional yeast, and beans. However, similar to iron, its absorption is lower compared to animal sources. To counteract this, vegan athletes should boost their zinc intake by 50 percent (to 16.5 mg/day for men and 12 mg/day for women). Additionally, methods to lower the phytic acid content in these foods should be employed to enhance zinc absorption.
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Calcium: Research indicates that calcium intake among vegans tends to be insufficient, which elevates their fracture risk. While dairy is not an option, vegan athletes can still achieve the recommended 1000 mg/day through careful dietary planning. Vegan-friendly sources of calcium include tofu, green vegetables (especially broccoli, kale, and bok choy), sprouts, pulses, beans, poppy seeds, flaxseeds, tahini, and fortified plant-based milk. It is important to note that spinach, rhubarb, and parsley contain oxalates that can hinder calcium absorption, but cooking can reduce oxalate levels.
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Iodine: Research indicates that many vegan athletes have insufficient iodine intake. The iodine levels in plant-based foods can vary due to factors like soil content and farming practices. Iodine-rich sources include sea vegetables like seaweed, while moderate amounts can be found in foods such as potatoes, prunes, and cranberries. Regular iodized table salt can potentially be replaced with sea salt if athletes consume these iodine-rich foods consistently, as sea salt contains some essential micronutrients. If achieving adequate levels is challenging, a supplement meeting the 150 ug/day requirement is suggested. Additionally, vegan athletes should be cautious about goitrogenic foods (like cruciferous vegetables, kale, soy, and cassava) that can impact iodine absorption; cooking methods like steaming and fermenting can help mitigate this effect.
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Vitamin D: While adequate sun exposure should theoretically prevent vitamin D deficiency for vegan athletes, our indoor lifestyle often leaves most people deficient in this vitamin. To address this, vegan athletes should consider using a vegan-friendly vitamin D3 supplement derived from lichen, which is more bioavailable compared to plant-based D2. Dosages typically range from 200-1000 IU, similar to animal-derived D3 supplements. This approach provides flexibility for personalized strategies based on individual blood levels (clinical deficiency is considered below 20 ng/day; optimal range is 40-70 ng/day).
Conclusion
In conclusion, a well-planned vegan diet can be suitable for athletes, but certain considerations are vital. Ensuring adequate intake of nutrients like vitamin B12, iron, zinc, calcium, iodine, and vitamin D is crucial due to potential deficiencies and lower bioavailability in plant-based sources. Careful dietary planning, supplementation, and mindful consumption of fortified foods and certain cooking methods can effectively address these concerns and support optimal performance and well-being among vegan athletes.
