In Tests of Athletic Performance, Plant-Based Diets Hold Their Own
A Rutgers Director of Behavioral Nutrition and other researchers find no significant differences in recreational athletes’ endurance or strength
Could athletes trade meat for plants and maintain their performance? In a multi-university study, researchers found that recreational runners and resistance trainers did just that.
The study, published in Nutrition Journal and coauthored by Rutgers Director of Behavioral Nutrition and Registered Dietitian, Peggy Policastro, found no statistically significant differences in how far recreational runners ran or how much weight resistance trainers lifted after four weeks on each diet.
Researchers compared the endurance and strength of physically active college students as they switched between plant-based and omnivore diets.
“The researchers wanted to solve a puzzle regarding whether switching from a meat-inclusive diet to a plant-based diet hurts an athlete’s physical performance,” said Policastro, director of nutrition at Rutgers Dining Services.
The question has become increasingly relevant as more athletes explore plant-based eating and encounter conflicting information about whether they can meet their nutritional needs without meat, Policastro said.
“Popular social media claims frequently spread misinformation that plant-based diets fail to provide enough calories or protein to meet the demands of exercise,” Policastro said. “The study specifically sought to test these claims by examining recreational student athletes who rely on university dining halls for most of their daily meals.”
The researchers recruited 36 undergraduate students from Rutgers, Stanford University, Vanderbilt University and the University of Reading in England. The group included 16 recreational runners and 20 resistance trainers who exercised three or four times a week. Of the participants, 56% identified as male; 42% female, and 2% nonbinary.
Each participant completed two four-week diet phases. During one phase, participants ate an omnivore diet and were asked to consume at least two servings of animal protein a day. During the other, they replaced the meat they would ordinarily eat with at least two servings of plant protein, such as beans, tofu or plant-based meat alternatives.
The order was randomly assigned. Some participants began with the plant-based diet, while others began with the omnivore diet. This crossover design allowed each participant to serve as his or her own comparison.
The plant-based phase focused on replacing meat with plant proteins and was broader than a strictly vegan diet.
Participants recorded what they ate at least three days a week and were asked to maintain their usual exercise routines. Researchers measured their performance before the study and at the end of each dietary phase.
Runners completed a 12-minute test in which they covered as much distance as possible. Resistance trainers completed three-repetition maximum tests using the chest press, lat pulldown and leg press.
The runners covered an average of 8,720 feet (nearly 2,658 meters) during the omnivore phase and 8,602 feet (nearly 2,622 meters) during the plant-based phase, a difference of about 118 feet (36 meters). The resistance trainers’ combined strength measurement was about 4% lower during the plant-based phase.
Neither difference reached statistical significance, meaning the researchers couldn’t rule out chance as the explanation for the minor variation.
“After four weeks on each diet, there were no statistically significant differences in athletic performance between the plant-based and omnivore phases,” Policastro said. “Runners achieved similar distances in their timed runs, and weightlifters maintained virtually the same maximum strength across chest, back and leg press exercises regardless of the diet they were following.”
Participants consumed considerably less protein during the plant-based phase. They ingested an average of about 71 grams a day, compared with 103 grams during the omnivore phase. Their average plant-based protein intake, however, remained within published recommendations for people engaged in general fitness activities.
The plant-based diet also contained more carbohydrates, fiber, iron and calcium, while the omnivore diet contained more saturated fat, cholesterol and vitamin B12. Reported calorie intake was similar during the two phases.
The researchers said these nutritional differences underscore the importance of planning a balanced diet. Vitamin B12, in particular, is often a necessary supplement for people who follow a fully plant-based diet over an extended period.
The study emerged from the Menus of Change University Research Collaborative, an international network of colleges and universities that uses campus dining halls as settings for studying eating habits and encouraging healthy, sustainable food choices.
Rutgers coauthor Alyssa Guidetti recruited the university’s participants and analyzed the Rutgers data under Policastro’s mentorship.
“She worked on this study as an undergraduate and then continued exploring the same topic through a systematic review for her master’s,” Policastro said. Guidetti is currently employed as a Sports Dietitian for Rutgers Athletics.
Participants also offered suggestions for making plant-based foods more appealing. Many said dining halls could improve the taste and variety of plant-based dishes. Some preferred beans, tofu and other whole foods to processed meat substitutes. Cultural background, familiarity, cost and access also influenced their willingness to choose plant-based meals.
The findings apply most directly to healthy, recreational college athletes over a short period. Their unusually low reported calorie totals also suggest that some food consumption went unrecorded.
For those reasons, the study cannot determine how plant-based eating might affect elite athletes or influence performance, muscle development and recovery over many months or years, Policastro said.
She added that the study doesn’t establish that the diets produce precisely identical results. Larger, longer and more tightly controlled studies will be needed.
Still, Policastro said the findings should reassure physically active students who want to incorporate more plant-based foods into their diets.
“This is important because it shows that everyday athletes can safely choose plant-based foods without worrying about harming their fitness or strength goals,” she said. “These findings provide evidence-based support for colleges to comfortably expand healthy and environmentally friendly plant-based menu options for their active student populations.”
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