UBC Theses and Dissertations
Body composition of vegetarian and omnivorous men Schwartz, Adam
Background: The relationship between diet and human body composition has become a popular topic in recent years. Despite the popularity of vegetarianism little research has been conducted in the area of vegetarianism and body composition, and the focus of the minimal research to date has been on children and women. There is recent evidence that suggests that among older men, the ability to gain skeletal muscle with resistance training may be substantially diminished for individuals consuming a vegetarian versus an omnivorous diet. This issue has yet to be examined in a group of younger males. There is also some evidence to suggest that vegetarians may have lower levels of body fat in comparison to omnivores. Objective: The objective of this study was to identify body composition differences (muscle and fat) between young men consuming either a vegetarian or omnivorous diet. Design: 54 young males between 18-30 y participated in this study. Half of these subjects were vegetarians. Body fat and muscle mass were estimated from anthropometry. In addition, subjects completed the Three-Factor Eating Questionnaire (TFEQ) and the Godin Leisure-Time Exercise Questionnaire (GLTEQ), which were used as indicators of eating habits and activity levels. All subjects completed 3-day diet records. Results: Vegetarians had significantly lower predicted muscle mass (30.9kg vs. 32.7, p=0.049 1-tailed), and a lower sum of 12 corrected muscle girths compared to omnivores (2.5x10⁶cm³ vs. 2.7x10⁶cm³, p=0.033 1-tailed). Vegetarians had higher dietary intakes of fiber (139.8 vs. 92.3, p=0.006) and polyunsaturated fats (67.5 vs. 42.7, p=0.001) and lower intakes of saturated fats (93.8 vs. 129.1, p=0.031) than omnivores. There were no significant differences between groups with regard to body fat, dietary restraint (TFEQ), activity levels (GLTEQ and reported hours of weekly activity), or other dietary intake variables. Conclusion: Vegetarian men were found to have significantly lower muscle mass than omnivores, and these differences could not be accounted for by dietary restraint or activity levels.
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