Meeting the nutrient reference values on a vegetarian diet.

Surveys over the past 10 years have shown that Australians are increasingly consuming more plant-based vegetarian meals. Many studies demonstrate the health benefits of vegetarian diets. As with any type of eating plan, vegetarian diets must be well planned to ensure nutritional needs are being met. This clinical focus project shows that well planned vegetarian diets can meet almost all the nutritional needs of children and adults of all ages. Sample single-day lacto-ovo-vegetarian meal plans were developed to comply with the nutrient reference values - including the increased requirements for iron and zinc at 180% and 150%, respectively, for vegetarians - for both sexes and all age groups set by Australia's National Health and Medical Research Council and the New Zealand Ministry of Health. With the exception of vitamin D, long-chain omega-3 fatty acids and extended iron requirements in pregnancy for vegetarians, the meal plans meet key requirements with respect to energy; protein; carbohydrate; total fat; saturated, poly- and monounsaturated fats; α-linolenic acid; fibre; iron; zinc; calcium; folate; and vitamins A, C, E and B12.

Vitamin B12 and vegetarian diets.

Vitamin B12 is found almost exclusively in animal-based foods and is therefore a nutrient of potential concern for those following a vegetarian or vegan diet. Vegans, and anyone who significantly limits intake of animal-based foods, require vitamin B12-fortified foods or supplements. Vitamin B12 deficiency has several stages and may be present even if a person does not have anaemia. Anyone following a vegan or vegetarian diet should have their vitamin B12 status regularly assessed to identify a potential problem. A useful process for assessing vitamin B12 status in clinical practice is the combination of taking a diet history, testing serum vitamin B12 level and testing homocysteine, holotranscobalamin II or methylmalonic acid serum levels. Pregnant and lactating vegan or vegetarian women should ensure an adequate intake of vitamin B12 to provide for their developing baby. In people who can absorb vitamin B12, small amounts (in line with the recommended dietary intake) and frequent (daily) doses appear to be more effective than infrequent large doses, including intramuscular injections. Fortification of a wider range of foods products with vitamin B12, particularly foods commonly consumed by vegetarians, is likely to be beneficial, and the feasibility of this should be explored by relevant food authorities.

Meeting nutritional needs on a vegetarian diet.

A vegetarian is a person who consumes a diet consisting mostly of plant based foods including fruit, vegetables, legumes, nuts, seeds and grains. Some vegetarians also consume eggs and dairy foods. Individuals choose to follow a vegetarian diet for a range of reasons, including animal rights and religion, but two common reasons are the health and environmental benefits of plant based eating.

Evidence for under-nutrition in adolescent females using routine dieting practices.

In Western countries the increasing prevalence of obesity in young people is a major public health concern. While the focus has been on reducing obesity, paradoxically the success of these campaigns may result in unhealthy nutritional practices. The aim of this study was to investigate the use and impact of weight control techniques on the health of adolescent females. Using Analysis of Variance we compared physiological and biochemical markers of health against responses to a modified, Schools Physical Activity and Nutrition Survey (SPANS) in 482 adolescent females (14-17 yrs) from secondary schools in the northern Sydney and Central Coast regions of New South Wales, Australia. Participants who 'often' used weight control methods had, on average, a healthy BMI of 22.5 (SD=3.7). However, comparison of blood derived markers between participants who 'never', 'occasionally' or 'often' used weight reduction techniques showed that, those who 'often' used weight control methods had significantly lower haemoglobin (p<0.05), alkaline phosphatase (p<0.001), bilirubin (p<0.05), albumin (p<0.05), total protein (p<0.05), and calcium (p<0.05), but higher blood levels of creatinine (p<0.05) and potassium (p<0.05). These data suggest that the use of common weight control techniques by healthy weight adolescent females can produce a metabolically divergent group whose biochemical markers are consistent with subtle levels of chronic under-nutrition.

The relative impact of a vegetable-rich diet on key markers of health in a cohort of Australian adolescents.

Childhood obesity is a widespread health problem in Australia. Overweight in childhood can lead to adult overweight and the development of risk factors for cardiovascular disease (CVD). Effective strategies for reducing childhood obesity are urgently required. A vegetarian diet has been shown to be an effective prophylactic to many lifestyle diseases in the adult population and may therefore be beneficial in children. However the metabolic demands of adolescents are different to adults and the impact of a vegetarian diet on CVD markers in this demographic is not certain. We compared key physiological and biochemical markers of health against responses to a modified, Schools Physical Activity and Nutrition Survey (SPANS) using one-way and two-way Analysis of Variance. 215 adolescents (14-15 yrs) from 5 Adventist secondary schools in the Sydney and Hunter regions of New South Wales, Australia, participated in this study. Adolescents consuming predominantly vegetarian foods showed significantly better scores on markers of cardiovascular health, including, body mass index (BMI), waist circumference, Cholesterol/High density lipoprotein ratio and low density lipoprotein. Adolescents consuming nuts more than once per week, also showed lower scores for BMI and serum glucose irrespective of their vegetarian status. Markers of general health including haemoglobin and average height were not different between groups; however a lower serum level of vitamin B12 was apparent in the vegetarian cohort. Surprisingly, exercise on its own was not statistically associated with any of the risk factors tested suggesting that diet may be the most significant factor in promoting health in this age group.