Abstract: Objective · To explore the obesity rate and related metabolic status of vegetarians in Shanghai and to compare with omnivores. Methods · A total of 270 vegetarians were recruited in Shanghai, and 270 omnivores were matched with 1:1 as a control group. General information and food intakes were collectedquestionnaires and food frequency questionnaires, respectively. Height, weight, waist circumference (WC), blood lipid, blood pressure, blood sugar and serum uric acid were collected and compared between vegetarians and omnivores. After controlling confounding factors such as age, gender, exercise time, and total energy, generalized estimation equation was used to analyze the association between vegetarian diet and various indicators. Results · Compared with omnivores, the body mass index (BMI) and WC of vegetarian were significantly lower (both P0.000). Compared with omnivores, the overweight or obesity diagnosedBMI and the central obesity diagnosedWC were significantly lower in vegetarians (10.0% vs 24.4%, P0.000; 2.2% vs 12.6%, P0.000), so were the total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, systolic blood pressure, fasting blood glucose, fasting insulin and female serum uric acid in vegetarians (all P0.000). After adjusting for age, gender, exercise time, sedentary time, total energy and other confounding factors, multivariate binary Logistic analysis of generalized estimating equation showed that vegetarians had significantly lower risk of overweight or obesity (OR0.355, 95% CI 0.211-0.598, P0.000) and of central obesity (OR0.131, 95% CI 0.046-0.376, P0.000). Multivariate linear regression analysis of generalized estimating equation showed that vegetarians had lower levels of total cholesterol (β-0.430 mmol/L, 95% CI -0.573 - -0.288, P0.000), high density lipoprotein cholesterol (β-0.151 mmol/L, 95% CI -0.201 - -0.101, P0.000), low density lipoprotein cholesterol (β-0.278 mmol/L, 95% CI -0.385 - -0.171, P0.000), fasting blood glucose (β-0.144 μmol/L, 95% CI -0.204 - -0.083, P0.000), and female serum uric acid (β-14.387 μmol/L, 95% CI -23.339 - -5.434, P0.000). Conclusion · Overweight or obesity in vegetarians, especially central obesity, is significantly lower than that in omnivores. Vegetarians have lower blood lipids, blood sugar and serum uric acid levels than omnivores. Vegetarian diet is an independently protective factor for obesity.

Key words: vegetarian, obesity, blood pressure, blood sugar, blood lipid, serum uric acid