Alex Morgan celebrates at the end of the Women's World Cup final soccer match between US and The Netherlands at the Stade de Lyon in Decines, outside Lyon, France, Sunday, July 7, 2019. US won 2:0. (AP Photo/David Vincent)

Soccer superstar Alex Morgan is many things to many people: co-captain to her U.S. women’s national team, social media celebrity to her 8.4 million Instagram followers, Best Female Athlete of the 2019 ESPYs, wife of soccer player Servando Carrasco, and role model to women and girls around the world.

She’s also a hero to animals — from her rescue pup, Blue, to all the cows and pigs and chickens she no longer consumes.

“I’m passionate about giving animals a voice,” Morgan told Reuters recently. “I even adopted a vegan diet, because it didn’t feel fair to have a dog I adore, and yet eat meat all the time.”

Morgan is part of the growing wave of top-tier athletes who are eliminating animal products — including meat, eggs and dairy — from the collection of foods they eat, instead embracing vegan, or plant-based, diets.

Along with Morgan — and five other women on the U.S. world cup soccer team, plus retired World Cup player Heather Mitts — other pro athletes who eat vegan include NBA point guard Chris Paul, tennis player Novak Djovic, Olympic weightlifter Kendrick Farris, tennis star Venus Williams (who went plant-based to improve symptoms of her autoimmune disorder, reportedly to great effect), Arnold Schwarzenegger, NFL defensive linebacker Derrick Morgan, possibly NFL quarterback Colin Kaepernick (though he’s never confirmed it beyond a 2018 tweeted with the hashtag #notbadforavegan) and Olympic cyclist Dotsie Bausch, who is so passionate about the issues involved that last year she formed a nonprofit called Switch4Good, promoting science-based benefits of a dairy-free lifestyle.

Alex Morgan, a member of the U.S women's national soccer team, accepts the award for best female athlete at the ESPY Awards on Wednesday, July 10, 2019, at the Microsoft Theater in Los Angeles. (Photo by Chris Pizzello/Invision/AP)

“One of the misconceptions in sports nutrition is that we have to have animal protein to perform at a high level. That’s just not true,” states James Loomis, M.D., a practitioner of internal medicine at Barnard Medical Center in Washington, D.C., and former team internist for the St. Louis Rams football team and the St. Louis Cardinals baseball team. Loomis, who is also a competitive marathoner, had been suffering with chronic health conditions when he saw the documentary Forks Over Knives, about the benefits of a plant-based diet, and was inspired to stop eating animal products.

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“I recently turned 60 and I'm able to do stuff physically now that I could never dream of doing and I attribute a lot of that to my diet,” Loomis, who appears (along with many of the athletes listed above) in the forthcoming Gamechangers, “a revolutionary new documentary about meat, protein, and strength,” tells Yahoo Lifestyle.

“Exercise is a highly inflammatory activity, and the Standard American Diet creates low-grade inflammation. So, exercising is throwing fuel on the fire. I’ve heard other athletes talk about a quicker recovery, and less injury, being the biggest change.”

Morgan, who has been prone to injury in the past, recently told the podcast Hurdle with Emily Abbate, “I’m knocking on wood right now, but I haven’t had a serious injury [since her last, which was before going vegan] and I credit that to my diet. I feel better all around, I feel like I have great energy, I feel like I’m sleeping really well, I feel like I’m just more clear-minded and not as reliant on caffeine as before.” She’s also seen a drop in her bad cholesterol.

Athletes who do go vegan, though — just like any person in general — must be deliberate when it comes to doing it healthily, and ensuring they get certain dietary requirements.

“Veganism, historically comes from an ethical place... and there's a lot of unhealthy stuff that's vegan,” Loomis explains. “So, a whole-food plant-based diet,” which he recommends and follows, “is vegan, but it avoids that highly processed food.”

Dotsie Bausch, Olympic medalist and founder of Switch4Good. (Photo courtesy of Switch4Good)

Some vitamins and minerals to be vigilant about, he says, include:

Vitamin B-12, 500 mcg a day, which vegans will need to supplement.

Calcium, which he calls a “faux nutrient of concern” for vegans, as there are many excellent, plant-based sources. “A cup of collard greens or a cup of tofu has as much as a cup of milk.” (Vitamin D, which many cite as a reason to keep drinking cow’s milk, is not naturally occurring in milk but fortified — just as it is in plant-based milks including soy, almond and oat.)

Iron, which can be of concern in pre-menopausal women, as iron from meat sources is easier for our bodies to absorb. To aid absorption from plant sources — which include cashew nuts, kale, hempseeds, tofu, blackstrap molasses and dried apricots — vegans should consume it with sources of vitamin C, such as citrus fruits.

Iodine. “That’s one that people don't talk about, but 150 mcg is needed a day,” Loomis says. While the biggest source used to come from iodized salt, many people now use sea salt or other none-fortified types. But it can be found in sea vegetables, such as nori and dulse, as well as kelp supplements.

Finally, there’s the ever-present question of protein, which even Morgan admitted she finds challenging.

“I think for a non-professional athlete it’s quite easy. But for me, I find some difficulty in making sure I get enough protein,” she told Hurdle. It’s very common for me to have two protein shakes in a day, almond milk and pea protein… and I like to incorporate protein into every meal that I possibly can, so that includes nuts, nut butters, black beans, chickpeas.”

But Loomis says most people are getting plenty of protein without overthinking it — even athletes — since all that’s really needed, according to the Daily Reference Intake (DRI) is 0.8 grams of protein per kilogram of body weight, or 0.36 grams per pound, amounting to 56 grams per day for the average man and 46 per woman; that’s upped to about 1.2 grams per kilogram for athletes, he says, easily found through the sources Morgan relies on, and others, including tempeh and tofu.

Read more from Yahoo Lifestyle:

• U.S. Women's Soccer Team files gender discrimination lawsuit alleging unfair pay: 'We believe it is our duty'

• Women's soccer stars ask bosses to let fans take day off to watch quarterfinal game: 'It's gonna be a big one!'

• Megan Rapinoe hailed as a patriot at Women’s World Cup Parade: ‘God bless her’

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