Plant-based diets provide well-established physical and environmental health benefits. These benefits stem in part from the degree of restriction of animal-derived foods. Historically, meat and other animal-derived proteins have been viewed as an integral component of athletes’ diets, leading some to question the adequacy of vegetarian or vegan diets for supporting athletic performance. The purpose of this review is to examine the impact of plant-based diets on human physical health, environmental sustainability, and exercise performance capacity. Based on currently available literature, it is unlikely that plant-based diets provide advantages, but do not suffer from disadvantages, compared to omnivorous diets for strength, anaerobic, or aerobic exercise performance. However, plant-based diets typically reduce the risk of developing numerous chronic diseases over the lifespan and require fewer natural resources for production compared to meat-containing diets. As such, plant-based diets appear to be viable options for adequately supporting athletic performance while concurrently contributing to overall physical and environmental health. Given the sparse literature comparing omnivore, vegetarian, and vegan athletes, particularly at the elite level, further research is warranted to ascertain differences that might appear at the highest levels of training and athletic performance.

There are conflicting reports regarding the efficacy of plant versus animal-derived protein to support muscle and strength development with resistance training. The purpose of this study was to determine whether soy and whey protein supplements matched for leucine would comparably support strength increases and muscle growth following 12 weeks of resistance training. Sixty-one untrained young men (n = 19) and women (n = 42) (18–35 year) enrolled in this study, and 48 completed the trial (17 men, 31 women). All participants engaged in supervised resistance training 3×/week and consumed 19 grams of whey protein isolate or 26 grams of soy protein isolate, both containing 2 g (grams) of leucine. Multi-level modeling indicated that total body mass (0.68 kg; 95% CI: 0.08, 1.29 kg; p < 0.001), lean body mass (1.54 kg; 95% CI: 0.94, 2.15 kg; p < 0.001), and peak torque of leg extensors (40.27 Nm; 95% CI: 28.98, 51.57 Nm, p < 0.001) and flexors (20.44 Nm; 95% CI: 12.10, 28.79 Nm; p < 0.001) increased in both groups. Vastus lateralis muscle thickness tended to increase, but this did not reach statistical significance (0.12 cm; 95% CI: −0.01, 0.26 cm; p = 0.08). No differences between groups were observed (p > 0.05). These data indicate that increases in lean mass and strength in untrained participants are comparable when strength training and supplementing with soy or whey matched for leucine.

Vegetarian diets provide an abundance of nutrients when carefully planned. However, vegetarian diets may have lower protein quality compared to omnivorous diets, a reflection of less favorable amino acid profiles and bioavailability. Hence, the current recommended dietary allowance for protein may not be adequate for some vegetarian populations. The purpose of this study was to determine dietary protein quality using the DIAAS (Digestible Indispensable Amino Acid Score) method in vegetarian and omnivore endurance athletes. DIAAS scores reflect the true ileal digestibility of the indispensable amino acids that are present in food items, and these scores can be used to compute the available protein in diet plans. Thirty-eight omnivores and 22 vegetarians submitted seven-day food records that were analyzed for nutrient content, and DIAAS scores were computed by diet group. Average available protein (g) was compared along with participants’ lean body mass and strength (quantified using the peak torque of leg extension). DIAAS scores and available protein were higher for omnivorous versus vegetarian athletes (+11% and +43%, respectively, p < 0.05). Omnivorous participants had significantly higher lean body mass than vegetarian participants (+14%), and significant correlations existed between available protein and strength (r = 0.314) and available protein and lean body mass (r = 0.541). Based upon available protein, as determined through the DIAAS, vegetarian athletes in this study would need to consume, on average, an additional 10 g protein daily to reach the recommended intake for protein (1.2 g/kg/d). An additional 22 g protein daily would be needed to achieve an intake of 1.4 g/kg/d, the upper end of the recommended intake range.

Vegetarian diets can satisfy nutritional requirements and have lower environmental impacts than those containing meat. However, fruits and vegetables are wasted at higher rates than meat. Reducing both food waste (FW) and the environmental impacts associated with food production is an important sustainability goal. Therefore, the aim of this study was to examine potential tradeoffs between vegetarian meals’ lower impacts but potentially higher FW compared to meat-containing meals. To examine this, seven consecutive days of plate FW data from Loma Linda University Medical Center (LLUMC) patients were collected and recorded from 471 meals. Mean total FW and associated greenhouse gas emissions (GHGE) were higher among meat-containing meals (293 g/plate, 604 g CO₂-eq/plate) than vegetarian meals (259 g/plate, 357 g CO₂-eq/plate) by 34 g (p = 0.05) and 240 g CO₂-eq (p < 0.001), respectively. Statistically significant differences were observed in both FW and associated GHGE across major food categories, except fruit, when comparing vegetarian and meat-containing meals. Overall, vegetarian meals were preferable to meat-containing meals served at LLUMC both in terms of minimizing FW and lowering environmental impacts. Other institutions serving vegetarian meal options could expect similar advantages, especially in reduced GHGE due to the high CO₂ embodied in meat.

College-aged women are not meeting weekly moderate-to-vigorous physical activity to support lipids protecting against cardiovascular disease onset. Participating in organized sport could assist in physical activity engagement and maintenance while positively impacting lipids predicting cardiovascular disease. However, women may be discouraged from participating in sports if they perceive benefits to be mostly seen at the higher competition levels, thus hindering seeking sports involvement at lesser-intensity levels. A total of N = 78 female athletes participating at the National Collegiate Athletic Association (n = 21), National Junior College Athletic Association (n = 29), and student club (n = 28) completed a personal characteristics questionnaire and provided blood samples to compare physical activity involvement and lipid health profiles. Linear regression modeling was used to assess how the independent variables (i.e., sport level, age, systolic blood pressure, race/ethnicity, sport/physical activity involvement hours per week, and years playing sports) on the dependent variables [i.e., total cholesterol, high density lipid (HDL), and total cholesterol-HDL ratio]. Total sample cholesterol 165.7 ± 34.0, HDL 62.8 ± 15.03, and total cholesterol-HDL ratio 2.8 ± 0.6 were all within a healthy recommendation range, along with per sport level. NJCAA sport level significantly predicted lower total cholesterol, p = 0.043, while identifying as Black significantly predicted higher total cholesterol, p = 0.008. Similarly, identifying as Black significantly predicted higher HDL, p = 0.021. Furthermore, increased systolic blood pressure significantly predicted higher total cholesterol-HDL ratios, p = 0.014. Organized sports participation may help meet physical activity requirements, support healthy lipid profiles, and ward off cardiovascular disease development in female college students regardless of competition level.

Background: Females are prone to urinary tract infections (UTIs) due to estrogen fluctuations affecting vaginal flora. While menstruating, increased fluid consumption to support urination frequency and void volume may be important, as the urethra and urinary tract are more predisposed to bacteria, particularly UTI pathogens. Aim: This study aimed to investigate the impact of hydration on urinary tract health during menstruation among underhydrated premenopausal women. Methods: Thirteen females participated in a 60-day 2 × 2 randomized crossover trial to evaluate the effectiveness of consuming ≥2.2 L of total beverage fluid intake, with 1.9 L being water, (intervention, INT) and maintaining habitual fluid intake (control, CON) on two subsequent menses. Participants completed fluid and urination diaries at days 2 and 5 after the onset of bleeding (day 1) to determine the fluid amount consumed and urination frequency. Urine concentration was assessed in afternoon (days 2 and 5) and uropathogenic bacterial activity in first-morning (days 3 and 6) urinations. General linear models assessed differences in bacterial and hydration outcomes. Results: The intervention led to a 62% mean total fluid increase, INT 3.0 ± 1.1 L and CON 1.9 ± 0.9 L, p < 0.001, η 2 = 0.459. Urination frequency was greater and urine concentration less in the INT to CON, all p _s < 0.05, η 2 range = 0.023–0.019. Only four cultures detected uropathogenic bacteria, with no patterns between conditions or days, making it difficult to determine the intervention's effectiveness. Conclusion: Fluid intake increased, and hydration status improved. No differences in uropathogenic bacterial activity were seen between the hydration and control conditions.