The metabolic health of New Zealand vegans : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Nutrition and Dietetics, Massey University, Albany, New Zealand

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Background: The popularity of a vegan diet is growing in New Zealand. Though there are potential nutrient deficiencies in a vegan diet, it is generally accepted that a vegan diet has greater metabolic benefits than a Western-style diet. Objectives: This cross-sectional study aimed to explore the metabolic health status and dietary intake of adults who had been consuming a vegan diet for 2+ years. Methods: Data were collected from The Vegan Health Research Programme. Participants completed questionnaires on demographic information, dietary practices and supplement use and a four-day food diary. Participants gave a blood sample for analysis of HbA1c, total cholesterol, LDL-C, HDL-C, Chol/HDL ratio, triglycerides and omega-3 index. Blood pressure, waist and hip circumference measurements were taken and body composition was measured using DXA. Results: Participants (N=212) had a mean (SD) age of 39.5 (12.4) years and were predominantly female (73.1%). Mean (SD) metabolic health markers of HbA1c, total cholesterol, LDL-C, HDL-C, Chol/HDL ratio, triglycerides, diastolic blood pressure and waist circumference were all within normal ranges. Females had a normotensive mean (SD) systolic blood pressure of 114.2 (12.9) mmHg and males were just above the low-risk normotensive category at 124.4 (12.0) mmHg. The mean (SD) omega-3 index result of 3.1 (1.2) placed most participants (86.3%) in the high-risk category for heart disease. Saturated fat intakes for males and females were 8.1% and 9.1% of energy, within the recommended range of 8-10% of energy. Dietary fibre intakes were high, at mean (SD) 55.0 (17.8) g/day for males and 43.4 (12.8) g/day for females. Conclusion: This is the first New Zealand study to examine the metabolic health and dietary intake of adult vegans. The results of metabolic health markers indicate that the vegan diet may confer cardioprotective benefits. The low omega-3 index of most participants is concerning, and warrants longitudinal research to assess the level of risk conferred by a low omega-3 index result in a population with no other metabolic risk factors. Dietary intake data shows the population is consuming saturated fat within the recommended range and high amounts of dietary fibre, which may go some way towards explaining the metabolic health status of the participants.