Canelo Alvarez will complete one of this century's most exciting boxing trilogies when he faces Gennadiy Golovkin on Sept. 17 in Las Vegas. The rivalry features hallmarks of some of the sport's all-time best -- explosive punching power by both fighters inside the ring, coupled with a fiery mutual dislike of each other outside of it.
Going into the trilogy, the fight also displays a subplot of its own: Alvarez's dalliance with a vegan diet, and a return to eating red meat following his most recent loss.
Before facing WBA light heavyweight champion Dmitry Bivol last May, Alvarez revealed he had adopted a near-vegan diet. He said he stopped eating red meat in 2018 following a positive test for clenbuterol, a banned substance sometimes fed illegally to cows in Mexico. Alvarez alleged he had come into contact with clenbuterol after eating tainted meat in his home country. Regardless, the Nevada Athletic Commission suspended him for six months, delaying his second fight with Golovkin -- a fight the Mexican boxer won via split decision.
"I'm not complicated when it comes to food. I adapt quickly," Alvarez told ESPN earlier this year. "I eat [a vegan diet] all week now and if one day the opportunity presents to eat red meat, chicken or whatever, I'll have no problem with that. But I do try to keep vegan [right now]."
The impetus behind Alvarez's change to vegan came after watching "The Game Changers," a documentary about athletes who incorporate plant-based diets. During training, Alvarez relied solely on vegan protein five days a week but ate fish and chicken on weekends.
"His output hasn't changed at all, physically he looks very strong and I don't see any change in him after he switched his diet," said Munir Somoya, who worked with Alvarez as part of his training team.
Come fight night, Bivol dominated Alvarez and retained his crown by way of unanimous decision. Bivol relied on his superior size and reach to hold Canelo to a career-low 84 punches landed over a full 12 rounds. Fighting at his preferred weight, Bivol used a two-inch reach advantage and taller frame, coupled with fluid movements and high energy output throughout to flummox Alvarez. In the later rounds, the usually durable Alvarez, who has won titles in four different weight classes, seemed sluggish and tired.
Alvarez's sudden dietary switch became a talking point after the fight. Among the critics, Alvarez's former promoter Oscar De La Hoya questioned the boxer's choices in the run-up to the Bivol fight.
"When you change something drastic like your diet overnight, you run the risk of it not working for your body, and it not adjusting properly," De La Hoya told reporters.
Since the loss, Alvarez is no longer training on a primarily plant-based diet as part of his fight plan to face Golovkin at super middleweight on Saturday.
"I tried to do it for some weeks and it's very complicated to change everything all of a sudden," Alvarez told the Associated Press in an interview. "So now, like I have all my life, I'm eating what I did before."
While Alvarez didn't use the diet to excuse his loss, his flirtation with veganism is notable in the sports world. In recent years, a number of elite athletes, including tennis stars Novak Djokovic and Venus Williams as well as Formula 1 legend Lewis Hamilton have followed plant-based diets.
A consistent vegan diet over months or even as quickly as weeks can positively affect the maximum amount of oxygen a person's body can absorb and use during exercise, while maintaining strength through a similar level of plant-based protein intake. That's according to The Impact of Vegan and Vegetarian Diets on Physical Performance and Molecular Signaling in Skeletal Muscle, an academic paper published in 2021 by members of the Institute of Sport Science at the University of Hildesheim in Germany. However, the authors admit "research on the influence of a vegan or vegetarian diet on exercise performance is scarce."
Because of the lack of research, it remains impossible to make any conclusive judgment across the board for any athlete who chooses to transition toward a plant-based diet. Any change -- whether plant-based or not -- can carry adverse effects for a high performance athlete, the experts say.
"In Canelo's case, going on a mostly plant-based diet shouldn't have been done so near to a fight," said Colette Gonzalez, a nutritionist from Alvarez's hometown of Guadalajara. "We can't change a high-performance athlete's diet in such a radical fashion and expect them to perform the same way."
Though Alvarez has made other dietary shifts during his career before fights he ended up winning, a vegan diet -- or even a near-vegan diet -- requires time to adapt, Gonzalez said. "There was clearly not enough time to gauge how the change would affect his muscle mass or his energy requirements for such an important fight."
As for the apparent fatigue Alvarez showed during later rounds in his last bout, Gonzalez says diet isn't entirely to blame. Higher weight and muscle mass requires the body to exert more energy, and though Alvarez had sparred and fought at 175 pounds before, a fast opponent with quick hands like Bivol simply outboxed him as time went on.
"Any time you gain weight, your body has to adapt. If your opponent is more accustomed to that weight, it's a disadvantage," Gonzalez said.
Combat sports in general can claim a few top-level ambassadors for vegan or vegetarian lifestyles. Former heavyweight champion David Haye famously took on a vegan diet in 2014 in defense of animal rights, and maintained his diet toward the end of his career. Haye's change in lifestyle, however, had come after the dwindling of his prime, fighting only in a handful of bouts on a plant-based diet.
"If you don't have any examples of plant-based athletes who are succeeding in your sport, you're going to think this doesn't work here," said Bryan Danielson, a pro wrestler for AEW who went vegan in 2009. "You need people who look like you or do what you do to succeed."
Danielson initially adopted the diet for health reasons -- while training for WWE events, he developed three staph infections over the course of a year. Before then, Danielson suffered through a weak immune system for most of his life. Shortly after the switch to veganism, the infections went away and the diet became permanent.
With the guidance of a trainer, Danielson -- known as Daniel Bryan during his WWE days -- reached peak physical yield under the diet. "I've deadlifted 518 pounds while on a full vegan diet," Danielson said. "There was no difference in my performance. The only difference was I instantly stopped getting sick."
When Alvarez chose to drop red meat prior to his second meeting with Golovkin, he still ate other types of animal protein. The shift was made in direct response to, arguably, his career lowlight.
Alvarez tested positive for clenbuterol in 2018, a banned substance catalogued as a performance-enhancing drug. He claimed it had accidently entered his body via tainted meat. In Mexico, the illegal practice of feeding cows pulverized clenbuterol pills in order to stimulate their growth and obtain more meat has been well documented.
A six-month suspension followed, pushing his May bout to September, and leading to claims of foul play from Golovkin's camp. For his part, Alvarez espoused moving forward with an abundance of caution when it came to what he put in his body.
"After what happened to me, I've been very careful," Canelo told ESPN then. "Really, too cautious, I think, [to the point] of not eating meat."
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When they finally clashed for their rematch on Sept. 15, Golovkin and Canelo staged The Ring magazine's Fight of the Year for 2018, with Alvarez narrowly coming out on top on two of the scorecards. The outcome did little to quell the debate over which fighter was better, as the controversy behind the draw in the first fight, coupled with Alvarez's previous doping suspension, created plenty of fodder.
Under the shadow of their third fight -- and as Canelo reels from the circumstances surrounding his second pro loss -- Golovkin continues to raise the issue, suggesting Alvarez's success might have less to do with diet and more with seeking unfair advantages.
"There are lab results," Golovkin told The Orange County Register in August. "And when asked, I said, 'Yes, I believe that he cheated.' And if somebody in his team didn't like my words, I believe it's their problem."
Alvarez will enter the ring at a dangerously unique point in his storied career. Coming off a loss for only the second time, he will stand opposite a man he has yet to beat convincingly -- whether in the scorecards or in the court of public opinion. Though Golovkin, who turned 40 in April, is likely in the latter stages of his career, a loss or even an unconvincing win will place detractors front and center.
Furthermore, Alvarez's flirtation with veganism will do little to subdue the debate as to whether a championship-level athlete in the most brutal of combat sports can thrive solely on a plant-based diet. Somoya is no longer advising Alvarez and has gone to work with another Mexican fighter, heavyweight Andy Ruiz.
"Someday, you'll have a fighter on [Alvarez's] level who wins championships and is on a vegan diet," Gonzalez said. "But that person will have likely been on the diet for years -- not just a few weeks."