Report on five specific health benefits associated with a vegetarian diet that is described by the authors.

The health benefits associated with a vegetarian diet that is described by the authors include:

·         Reduce the risk of type 2 diabetes

·         Low risk of hypertension

·         Low risk of dementia

·         Improved lipid profile

·         Lower body mass index (BMI)

The above are some of the key benefits which the researchers have identified in the study regarding the vegetarian diet. A vegetarian diet is considered healthier for individuals and more beneficial than the meat diet.

2. Name five nutrients of concern for vegetarians. Select two of these nutrients and from your background knowledge, explain how low intake of each could impair physical performance. 

 The five nutrients which are a major concern for vegetarians include:

·         Vitamin B12

·         Iron

·         Zinc

·         Creatine

·         Protein

Iron and zinc are highly important nutrients for the human body. The lack of iron can cause a decrease in the red blood cells. Due to low hemoglobin and red blood cells the body cannot work efficiently. Zinc deficiency can cause loss of appetite, hair loss, and other medical conditions. In the short low intake of zinc and iron can reduce the physical performance of the human body.

3.  Briefly describe the results of two prior intervention trials of athletic performance and Lacto-Ovo vegetarian diets and their limitations. This helps the authors justify why the current study is needed.

The results of prior studies did not show an effect on the endurance performance of the athletes. The results of the prior studies have a significant amount of limitations. In the prior studies, those individuals are also included who usually eat meat but adopted a vegetarian diet just for the study. They consume a vegetarian diet only in the period of study. The study should include individuals who were consuming a vegetarian diet from a longer time period. Due to these issues, the current study was needed.

4.  What is the purpose of this study?

The purpose of the current study is to provide a cross-sectional research study that observes performance measures and body composition of the athletes that are vegetarian and omnivore. The researchers have chosen the athletes that are following their diet plan from 3 months.

Materials and Methods

5. Describe the age range, diet, and athletic training of the participants recruited for the study.

For the research purpose, both women and men were recruited for the study. The elected participants were vegetarian and omnivores. The participants were a part of NCAA or training for an endurance race that includes cycling race, marathon, etc.  The age of the participants was between 21-58 years. The diet questions were asked from the participants in which 8 vegetarians said that they ate meat occasionally. They were then classified as omnivores.

6. Do the authors specify the type of vegetarian diet followed by “vegetarian” participants? (see other sections of the article). If you were the investigator, would you want the diet groups to be clearly distinct, such as vegans vs. omnivores who eat meat several times a week? Why or why not?

The study has not specified the type of vegetarian diet but provided detail regarding the nutrient differences by the diet group. The vegetarian diet includes more carbohydrates, fiber, and fats whereas the omnivore’s diet includes more protein and vitamin B12. As an investigator, I would classify the diet group into vegans and omnivores so that the study can identify the difference between those two groups. Without classification, it will be difficult to differentiate the impact of diets on the human body.

7. Was the study design longitudinal or cross-sectional? Define each.

The study design was cross-sectional instead of longitudinal. The study makes the comparison of the vegetarian diet and omnivore diet in the athlete at the same point in time which shows that it was a cross-sectional study. In longitudinal studies, the comparison was made over an extended period of time. Both cross-sectional studies and longitudinal studies based on observations. In these studies, the researchers gather data from respondents without manipulating the environment of the study.

8. What methods were used to measure body composition, maximal oxygen uptake, and leg strength?

The body composition is measured using the (DXA) dual-energy X-ray absorptiometry. The leg strength of the athletes is measured using the dynamometer. The maximal oxygen uptake or aerobic capacity is measured using the Bruce protocol treadmill test. The measurement has provided the information which is required for understanding the endurance of the athletes.

 9. A questionnaire at recruitment identified vegetarians vs. omnivores. For the actual study, dietary intake data were collected.

How dietary intake was measured and for how many participants were dietary intake data complete? Is this proportion of participants with diet data sufficient/acceptable, in your opinion? Explain.

The dietary intake of the participants was measured through diet questions. 35 participants in each group are recruited for the study. It means that dietary intake data was completed for the 70 participants. The data for 70 participants is sufficient for the study because it will provide the information which the researchers are looking for.

10. Were the investigators blinded to the participant diet group? Explain why blinding is an important consideration in a study’s design.

The investigators were not blinded to the participant diet group. The investigators know about the diet group of the participants because they have recruited the participants based on their diet groups. However, blinding is considered important in the study because if the investigators are going to be blinded about the participant diet group then they will unable to include their personal opinion or biases in the study.

Statistical analysis

11. Did the study enroll enough participants to detect a 10% difference between diet groups in aerobic capacity or strength? Which outcome (capacity or strength) seems more important to you in understanding how vegetarianism affects physical performance? Explain.

According to Hanne et al 80% power and an alpha level of 5%, 15 participants per group were needed to detect a 10% difference in strength and 80 participants per group were needed to detect a 10% change in aerobic capacity between groups

Results

Recall that statistically significant differences are marked by a p-value of <0.05. P values between 0.05 and 0.1 may be considered a tendency or trend toward statistical significance. P values >0.1 suggest no statistical difference between groups.

12. Table 1. For which sex and measure were significant effects of diet reported (note the asterisks * and ** definitions in the footnote)?

Table 1

Participant characteristics by diet group (vegetarian, VEG; omnivorous, OMN) ¹.

In the above table, the effect of diet on male and female athletes is presented. The significant amount of peak torque difference can be seen in the vegetarian and omnivore athletes. The male vegetarian peak torque is 114.4 whereas the peak torque of omnivore male athletes is 124.2. The body mass of vegetarian athletes is round about 73.3 kg whereas the body mass of omnivore athletes is round about 78 kg. the visceral fat and METS also shows significant differences.

13. Table 2. For which nutrients were intakes significantly different between diet groups?

Table 2

Nutrient differences by diet group (vegetarian, VEG; omnivorous, OMN) ¹.

The carbohydrates, fibers, and fats are higher in the vegetarian diet as compared to the omnivore diet. other vitamins such as vitamin c are also higher in the vegetarian diet. The cholesterol levels and saturated fats are lower in the vegetarian diet. The omnivore diet, on the other hand, is rich in vitamin B12, phosphorus, selenium, zinc and vitamin D.

14. Did lean body mass seem to affect leg strength in these athletes? Explain.

The lean body mass of vegetarian athletes was lower than the omnivore athletes. The study has discussed that despite the lean body mass difference between the two groups there were no differences in peak torque. The study discussion has also stated that there were lean body mass differences in two group athletes but the strength of the athletes increased similarly. 

Discussion and Conclusions

15. List the support given by the authors for “increased rigor” (more precise/reliable study methods) of this study vs. other published similar studies.

The support given by the authors for increased rigor include:

·         The maximal oxygen uptake is measured through treadmill instead of cycle ergometer

·         Body composition is measured through DXA scan instead of skinfolds

·         Both nutrient intake and athlete performance differences are included in the study

16. What limitations of this study are noted by the authors? What other limitations (s) do you see?

The key limitations of this study include:

·         Small sample size

·         Athletes variable level of experience in fitness level and sports

·          Some athletes were trained for small distance races.

17. Who funded (supported) the study?   If the study was funded by “VeggieLand” or another vegetarian food company, would you be concerned about the reliability of results? Explain.

The study was funded by the Graduate and Professional Student Association (GPSA) at Arizona State University. If this study supported by any vegetarian food company than the reliability of the study might get affected because of the personal interests of the vegetarian company.