Objective: To assess the prevalence of vegetarians in the whole Shanghai population, and to know the vegetarians' brief and behavior on diet, nutrition and health.
Methods: First, a multi-staged, stratified, clustered random sampling design was used. A total representative sample of 4 004 Shanghai resident subjects were asked if they were vegetarians and what type of vegetarian they were by a well-designed questionnaire. Second, from ten vegetarian restaurants located in Shanghai. 473 adult vegetarians completed a questionnaire about vegetarian status, among whom 274 vegetarians completed a detailed questionnaire about their brief and behaviors on diet, nutrition and health status.
Results: Of 4 004 subjects, 0.77% were vegetarians (0.45% were lacto-vegetarians and 0. 12% were vegans). The average age was 65. 0 years. 74. 2% of the vegetarians were female. Of 473 vegetarians, 70. 2% of the vegetarians had college or higher education. Compared to vegans, lacto-ovo-vegetarians were significantly younger and had higher educational level. The main reasons for choosing a vegetarian lifestyle were religion (49. 3%) and health (31. 3%). Furthermore, more vegan tend to be Buddhist. Vegetarians were more concerned about their health (209/274, 76. 5%) , the consumption of balance diets (183/274, 66. 8%). Comparing with lacto-ovo-vegetarians (58. 3%) more vegans (70. 4%) believed in that vegetarian diet is a kind of healthy dietary pattern and will not have any nutrients deficiency (P = 0. 037). Vegetarians consumed more healthy foods (e. g.,whole grains, vegetables, soy products, and nuts) than the general population (P < 0. 01). Only 5. 8% of the vegetarians took dietary supplements.
Conclusion: 0. 77% of population in Shanghai was vegetarian. The two main reasons for adopting a vegetarian lifestyle were religion and health. The vegetarians tend to have more nutrition knowledge, better attitude and behavior on health. However, most of the vegetarians had not realized the nutrient deficiency risk of vegetarian diets.