Degree Name

Doctor of Philosophy (Health Sciences)


School of Medicine


Vegetarian-based dietary patterns have been associated with protection against many chronic diseases. These benefits have been attributed to the high intakes of food components such as fruits, vegetables, nuts, seeds and legumes and absence of animal foods as part of a vegetarian diet, with some researchers suggesting there may be anti-inflammatory effects of following a vegetarian-based diet. Interestingly, there are growing numbers of individuals adopting a diet of this nature, with athletes being overrepresented in the consumption of vegetarian-based diets. Despite the increase in vegetarian-based diet popularity, there is a lack of research describing the motives, dietary behaviours, supplementation patterns, nutrient intakes and diet quality of individuals following a vegetarian-based diet, particularly for athletes. If differences in nutritional composition between athletes following omnivorous and vegetarian-based dietary patterns exist, there may also be various differences in exercise related physiological outcomes including inflammatory and immunological markers. The central hypothesis of this thesis is that due to differences in nutrient composition and diet quality between vegetarian and non-vegetarian-based dietary patterns, disparities will result in various inflammatory and immune biomarkers as well as other endurance exercise related physiology.

In order to explore the dietary behaviors, supplementation patterns and motives in this population group, an online survey was implemented (Study 1a). Here, it was found that self-reported recreational and competitive athletes adopting a vegetarian-based diet were likely doing so with the aspiration of improving their exercise performance. A nutrient analysis in a subset of this study (Study 1b) suggested that a vegetarian-based dietary pattern could provide a high diet quality for recreational athletes with sufficient nutrients to support physical activity. However, intake of some nutrients in this self-reported vegetarian-based population were insufficient such as for vitamin B12 and long chain omega-3 polyunsaturated fatty acids. As this was an online, self-reported population of individuals, it was important to contrast dietary patterns between vegetarian and non-vegetarian dietary patterns and to explore if differences in inflammatory and immune markers as a function of dietary pattern existed between groups which also have relevance to exercise outcomes.

FoR codes (2008)




Unless otherwise indicated, the views expressed in this thesis are those of the author and do not necessarily represent the views of the University of Wollongong.