Position of the American Dietetic Association: vegetarian diets

Vegan Diets for Children: A Narrative Review of Position Papers Published by Relevant Associations

The scientific discourse on vegan diets for children and adolescents primarily involves referencing position statement papers from different scientific and professional organizations, including paediatric associations. Over the past two decades, specialized associations have issued official statements and published position papers about adopting well-designed vegan diets during crucial life stages, including pregnancy and lactation, infancy, and childhood. A subset of these associations firmly supports the notion that a well-designed vegan diet can indeed be healthy and support normal growth and development during particularly delicate life stages, emphasizing careful planning, vitamin B12 supplementation, and regular supervised medical and dietetics oversight. In contrast, specific paediatric associations caution against vegan diets for children and adolescents, citing potential harm and the lack of adequate substantiation. These criticisms in position papers frequently point to lower-quality studies and/or outdated studies. Additionally, concerns extend to comparing vegan and omnivorous diets, considering public health issues such as obesity and early stages of cardiovascular disease as well as the risk of prediabetes and type 2 diabetes. Notably, some scepticism stems from studies where children's adherence to a well-designed vegan diet is incomplete. Scientific rigor suggests performing a comparable assessment of omnivorous and vegan diets. This narrative review highlights the need for a comprehensive, up-to-date literature review to inform balanced perspectives on vegan diets for children and adolescents. Researchers and decision-makers should aim to actively improve the design and consistent implementation of both diet types.

Prevention and Treatment of Retinal Vein Occlusion: The Role of Diet-A Review

Retinal vein occlusion (RVO) is the second most common retinal disorder. In comparison to diabetic retinopathy or age-related macular degeneration, RVO is usually an unexpected event that carries a greater psychological impact. There is strong evidence to suggest that cardiovascular diseases are the most common risk factors in this pathology and it has long been known that a higher consumption of fish, nuts, fruits, and vegetables has a protective effect against these types of conditions. In the last several years, interest in plant-based diets has grown in both the general population and in the scientific community, to the point to which it has become one of the main dietary patterns adopted in Western countries. The aim of this review is to investigate the potential impact of macro- and micronutrients on retinal vein occlusion.

Vegetarian and Vegan Private Label Products as a Challenging Trend in Addressing the Customers Within Sustainable Food Consumption—A Case Study of Slovakia

The meat consumption at the current level is highly unsustainable. Because of the problems that meat production causes to the environment, it is considered as one of the main problems. Vegetarian and vegan private label products represent a new challenging trend in addressing the customers within sustainable food consumption at affordable prices. The submitted paper aimed to find out whether Slovak consumers know and subsequently buy products of the private brand targeted on vegans and vegetarians, in which product categories they do so, how they perceive them and what attracts and discourages them. The research was carried out in the period from September to December 2020, when a total of 2,011 respondents from all over Slovakia took part. As we have focused only on consumers who know the product line of private labels targeted on vegans and vegetarians (product line of vegan and vegetarian products), we have further analyzed and interpreted only the answers of 978 respondents. For the need to obtain the main aim of the research, we have formulated four theoretical assumptions and five hypotheses, whose veracity was verified with the use of selected statistical methods and techniques processed out at statistical programs XL Stat, SAS Enterprise Guide 7.1. and SAS 9.4. The key finding of our research is, that even if it could be assumed that the products of this specific private label will be bought only by respondents from the vegan or vegetarian category, the opposite is true—the private label is known and bought by the respondents from the category “I eat everything,” which means that it is necessary to think about this product line, to wider it and continue in the improvement of its quality as this is what the customers want.

Trends in types of protein in US adults: results from the National Health and Nutrition Examination Survey 1999-2010

OBJECTIVE

To delineate trends in types of protein in US adults from 1999 to 2010, we examined the mean intake of beef, pork, lamb or goat, chicken, turkey, fish, dairy, eggs, legumes, and nuts and seeds (grams per kilogram of body weight) among adults and according to subgroups, including chronic disease status.

DESIGN

Six cycles of the repeated cross-sectional surveys.

SETTING

National Health and Nutrition Examination Survey 1999 to 2010.

PARTICIPANTS

US adults aged ≥20 years (n 29 145, range: 4252-5762 per cycle).

RESULTS

Overall, mean chicken (0·47 to 0·52 g/kg), turkey (0·09 to 0·13 g/kg), fish (0·21 to 0·27 g/kg) and legume (0·21 to 0·26 g/kg) intake increased, whereas dairy decreased (3·56 to 3·22 g/kg) in US adults (P <0·03). Beef, lamb or goat intake did not change in adults or among those with a chronic disease. Over time, beef intake declined less, and lamb or goat intake increased more, for those of lower socio-economic status compared with those of higher socio-economic status.

CONCLUSIONS

Despite recommendations to reduce red meat, beef, lamb or goat intake did not change in adults, among those with a chronic disease or with lower socio-economic status.

Shifting Food Systems: Increasing Well-Being Through Plant-Based Approaches

Growing evidence reveals food production systems and consumption practices contradict goals for environmental well-being and population health. This interdisciplinary paper reviews research for impacts from diets on non-communicable human diseases, climate change, and animal well-being. With increasing pressures to innovate and reduce economic as well as emotional costs associated with ill-health, our recommendations could positively impact policy.

Whole-foods, plant-based diet alleviates the symptoms of osteoarthritis

Objective. To evaluate the effectiveness of a whole-foods, plant-based diet (WFPB) to reduce symptoms of osteoarthritis. Methods. Six-week, prospective randomized open-label study of patients aged 19–70 with osteoarthritis. Participants were randomized to a WFPB (intervention) or continuing current diet (control). Outcomes were assessed by mixed models analysis of participant self-assessed weekly SF-36v2 domain t scores, weekly Patient Global Impression of Change (PGIC) scales, and mean weekly Visual Analog Scale (VAS) pain assessment. Mixed models analysis also evaluated pre-post change from baseline level for standard clinical measures: weight, BMI, body temperature, pulse, and blood pressure. Results. Forty participants were randomized. Thirty-seven of them, 18 control and 19 intervention, completed the study. The intervention group reported a significantly greater improvement than the control group in SF-36v2 energy/vitality, physical functioning, role physical, and the physical component summary scale. The differences between the intervention and control PGIC scales were statistically significant over time. Intervention group improvement in VAS weekly mean was also significantly greater than that of the control group from week 2 onward. Conclusion. Study results suggest that a whole-foods, plant-based diet significantly improves self-assessed measures of functional status among osteoarthritis patients.

Plasma n-3 and n-6 fatty acids and inflammatory markers in Chinese vegetarians

Background

Polyunsaturated fatty acid (PUFA) intake favorably affects chronic inflammatory-related diseases such as cardiovascular disease; however, the relationship between the PUFA and inflammatory factors in the healthy vegetarians were not clear. We aimed to investigate the plasma fatty acids status, and its association with plasma inflammatory factors in Chinese vegetarians and omnivores.

Methods

A total of 89 male vegetarians and 106 male omnivores were participated the study. Plasma concentrations of inflammatory factors were detected by ELISA, and as standard methods fatty acids were extracted and determined by chromatography.

Results

Compared with omnivores, vegetarians have significant higher interleukin-6 (IL-6), plasma n-6 PUFA, n-6/n-3, and 18:3n-3; while they have significant lower leukotriene B4 (LTB4), cyclo-oxygenase-2 (COX2) and prostaglandin E2 (PGE2), 20:5n-3, 22:5n-3, 22:6n-3, and n-3 PUFA. In vegetarians, plasma 20:4n-6 was significant positively related to TNF-α. LTB4 was significantly positively related to plasma 22:6n-3, and negatively associated with n-6 PUFA.

Conclusion

Vegetarians have higher plasma n-6 PUFA and IL-6, but lower LTB4, n-3 PUFA, 22:6n-3, COX2 and PGE2 levels. It would seem appropriate for vegetarians to increase their dietary n-3 PUFA, while reduce dietary n-6 PUFA and thus reduce the risk of chronic inflammatory-related diseases.

Associations of plasma phospholipid fatty acids with plasma homocysteine in Chinese vegetarians

The association of plasma phospholipid (PL) fatty acid composition with plasma homocysteine (Hcy) in Chinese vegetarians is not understood. The main aim of the present study was to investigate the plasma PL fatty acid status, and its association with plasma Hcy in Chinese vegetarians and omnivores. A total of 103 male vegetarians and 128 male omnivores were recruited in Linyin Temple, Hangzhou. Plasma Hcy and PL fatty acid concentrations were determined by standard methods. Compared with omnivores, plasma PL n-3 PUFA (P< 0·001), 22 : 6n-3 (P< 0·001), 22 : 5n-6 (P= 0·021), 22 : 2n-6 (P< 0·001) and SFA (P= 0·017) were significantly lower, while plasma PL n-6 PUFA (P= 0·007) and total PUFA (P< 0·001) were significantly higher in vegetarians. The prevalence of hyperhomocysteinaemia (HHcy) in vegetarians (26·47 %) was significantly higher than that in omnivores (13·28 %). In vegetarians, plasma PL 22 : 6n-3 (r − 0·257, P= 0·046) was significantly negatively associated with plasma Hcy. In omnivores, plasma PL 18 : 1n-7 (r 0·237, P= 0·030) was significantly positively associated with plasma Hcy. Plasma PL 22 : 6n-3 (r − 0·217, P= 0·048) was negatively associated with plasma Hcy in omnivores. Plasma PL SFA were positively associated with the prevalence of HHcy. It would seem appropriate for vegetarians to increase their dietary n-3 PUFA and decrease dietary SFA, and thus reduce the risk of HHcy.

Effects of plant-based diets on plasma lipids

Dyslipidemia is a primary risk factor for cardiovascular disease, peripheral vascular disease, and stroke. Current guidelines recommend diet as first-line therapy for patients with elevated plasma cholesterol concentrations. However, what constitutes an optimal dietary regimen remains a matter of controversy. Large prospective trials have demonstrated that populations following plant-based diets, particularly vegetarian and vegan diets, are at lower risk for ischemic heart disease mortality. The investigators therefore reviewed the published scientific research to determine the effectiveness of plant-based diets in modifying plasma lipid concentrations. Twenty-seven randomized controlled and observational trials were included. Of the 4 types of plant-based diets considered, interventions testing a combination diet (a vegetarian or vegan diet combined with nuts, soy, and/or fiber) demonstrated the greatest effects (up to 35% plasma low-density lipoprotein cholesterol reduction), followed by vegan and ovolactovegetarian diets. Interventions allowing small amounts of lean meat demonstrated less dramatic reductions in total cholesterol and low-density lipoprotein levels. In conclusion, plant-based dietary interventions are effective in lowering plasma cholesterol concentrations.

A new Japanese vegetarian food guide

Vegetarianism continues to gain popularity in Japan and the Westernized world, in part from decades of science supporting the health advantages of properly planned vegetarian-based diets. Although there are Asian nutritional tools, one specific to a Japanese vegetarian diet is lacking. Thus, the Japanese vegetarian food guide (JVFG) was developed and based in part on the American Dietetic Association position paper for vegetarian diets and the Japanese Food Guide Spinning Top. The JVFG was developed by collecting dietary information from 3 different institutes in Japan that specialize in regularly offering vegetarian meals. The JVFG was divided into 6 groups with respective recommended servings: vegetables (7.5), grains (4.5), protein foods (4), milk (3), fruits (2), and fats, sugar, and seasonings (<3). The JVFG was developed so that it would adequately provide for all nutrients and be structured for practical use by the general public as well as health professionals.

Vegetarian Diets and Weight Status

The increasing global health problems of overweight and obesity are associated with coronary heart disease, hypertension, diabetes, osteoarthritis, and certain cancers, among other health concerns. Vegetarian diets are associated with reduced body weight, lower incidence of certain chronic disease, and lower medical costs compared with non-vegetarian diets. We reviewed the literature to ascertain the extent to which and by what mechanism(s) a plant-based diet may mediate body weight.

Vegetarian eating for children and adolescents

During the past decade, vegetarianism has risen in popularity among American families. Well-planned vegetarian diets can satisfy the nutritional needs and promote normal growth of infants and children. Research has highlighted nutritional advantages to vegetarian diets and has indicated that this style of eating can lead to lifelong healthy eating habits when adopted at a young age. Several vitamins, minerals, and macronutrients may be deficient within a vegetarian diet. Careful nutrition assessment and counseling will allow nurse practitioners to play a key role in encouraging families to adopt healthy eating habits to assist in disease prevention.

Public health implications of meat production and consumption

The high level of meat and saturated fat consumption in the USA and other high-income countries exceeds nutritional needs and contributes to high rates of chronic diseases such as cardiovascular disease, diabetes mellitus and some cancers. Affluent citizens in middle- and low-income countries are adopting similar high-meat diets and experiencing increased rates of these same chronic diseases. The industrial agricultural system, now the predominant form of agriculture in the USA and increasingly world-wide, has consequences for public health owing to its extensive use of fertilisers and pesticides, unsustainable use of resources and environmental pollution. In industrial animal production there are public health concerns surrounding feed formulations that include animal tissues, arsenic and antibiotics as well as occupational health risks and risks for nearby communities. It is of paramount importance for public health professionals to become aware of and involved in how our food is produced.

Nutrient Adequacy of a Very Low-Fat Vegan Diet

This study assessed the nutrient adequacy of a very low-fat vegan diet. Thirty-nine men (mean age=65 years) with early stage prostate cancer who chose the "watchful waiting" approach to disease management, were instructed by a registered dietitian and a chef on following a very low-fat (10%) vegan diet with the addition of a fortified soy protein powdered beverage. Three-day food diaries, excluding vitamin and mineral supplements, were analyzed and nutrient values were compared against Dietary Reference Intakes (DRI). Mean dietary intake met the recommended DRIs. On the basis of the Adequate Intake standard, a less than adequate intake was observed for vitamin D. This demonstrates that a very low-fat vegan diet with comprehensive nutrition education emphasizing nutrient-fortified plant foods is nutritionally adequate, with the exception of vitamin D. Vitamin D supplementation, especially for those with limited sun exposure, can help assure nutritional adequacy.

The effects of a low-fat, plant-based dietary intervention on body weight, metabolism, and insulin sensitivity

PURPOSE

This study investigated the effect of a low-fat, plant-based diet on body weight, metabolism, and insulin sensitivity, while controlling for exercise in free-living individuals.

SUBJECTS AND METHODS

In an outpatient setting, 64 overweight, postmenopausal women were randomly assigned to a low-fat, vegan diet or a control diet based on National Cholesterol Education Program guidelines, without energy intake limits, and were asked to maintain exercise unchanged. Dietary intake, body weight and composition, resting metabolic rate, thermic effect of food, and insulin sensitivity were measured at baseline and 14 weeks.

RESULTS

Mean +/- standard deviation intervention-group body weight decreased 5.8 +/- 3.2 kg, compared with 3.8 +/- 2.8 kg in the control group (P = .012). In a regression model of predictors of weight change, including diet group and changes in energy intake, thermic effect of food, resting metabolic rate, and reported energy expenditure, significant effects were found for diet group (P < .05), thermic effect of food (P < .05), and resting metabolic rate (P < .001). An index of insulin sensitivity increased from 4.6 +/- 2.9 to 5.7 +/- 3.9 (P = .017) in the intervention group, but the difference between groups was not significant (P = .17).

CONCLUSION

Adoption of a low-fat, vegan diet was associated with significant weight loss in overweight postmenopausal women, despite the absence of prescribed limits on portion size or energy intake.

Long-term ovo-lacto vegetarian diet impairs vitamin B-12 status in pregnant women

A well-planned vegetarian diet has been stated to be adequate during pregnancy. The aim of the present study was to compare serum vitamin B-12 and homocysteine concentrations in pregnant women (n = 109) consuming vegetarian and Western diets and to evaluate the adequacy of current dietary reference intakes of vitamin B-12 for these women. Pregnant women adhering to vegetarian diets for at least 3 y, with subgroups of ovo-lacto vegetarians (OLVs; n = 27), low-meat eaters (LME, n = 43), and women eating an average Western diet (control group, n = 39), were recruited. Dietary vitamin B-12 intake, serum vitamin B-12, and plasma total homocysteine (tHcy) concentrations were measured in wk 9-12, 20-22, and 36-38 of pregnancy. During pregnancy serum vitamin B-12 concentrations of ovo-lacto vegetarians (P < 0.001) and low-meat eaters (P = 0.050) were lower than those of the control group. We observed the combination of low serum vitamin B-12 concentrations and elevated plasma tHcy in 22% of ovo-lacto vegetarians, in 10% of low-meat eaters, and in 3% of controls (P = 0.003). In OLVs, serum vitamin B-12 predicted 60% of the plasma tHcy variation (P < 0.001), but in LMEs and controls only <10% (NS). Serum vitamin B-12 concentrations increased and plasma tHcy decreased sharply with increasing dietary intake of vitamin B-12 toward a cutoff point of 3 mug/d. Pregnant women consuming a long-term predominantly vegetarian diet have an increased risk of vitamin B-12 deficiency. Current recommended dietary intakes urgently need reevaluation.

Effects of a long-term vegetarian diet on biomarkers of antioxidant status and cardiovascular disease risk

OBJECTIVE

We compared plasma biomarkers of antioxidant status, oxidative stress, inflammation, and risk for coronary heart disease in long-term vegetarians and age- and sex-matched omnivores.

METHODS

Thirty vegetarians (mean age +/- standard deviation: 44.2 +/- 9.0 y) were recruited. The subjects had been vegetarian for 5 to 55 y (21.8 +/- 12.2 y). The control group comprised 30 adults selected by age-stratified sampling from a community health project (mean age: 44.0 +/- 9.2 y). Fasting plasma total antioxidant status (ferric-reducing antioxidant power), ascorbic acid (AA), alpha-tocopherol (total and lipid standardized), malondialdehyde, total cholesterol, triacylglycerol, uric acid (UA), and high-sensitivity C-reactive protein (hsCRP) were measured.

RESULTS

Plasma AA was significantly higher in the vegetarians than in the omnivores (90.5 +/- 21.0 and 61.8 +/- 17.0 microM; P < 0.001). The vegetarians had lower concentrations of triacylglycerol, UA, and hsCRP. Plasma total and lipid-standardized alpha-tocopherol concentrations were also lower in the vegetarians: 22.0 +/- 5.9 and 27.0 +/- 7.9 microM versus 3.76 +/- 0.57 and 4.23 +/- 0.58 microM per millimoles per liter of total cholesterol plus triacylglycerol, respectively. There was a significant inverse correlation between AA and UA (r = -0.343, P < 0.01; n = 60) and between AA and hsCRP (r = -0.306, P < 0.05; n = 55). Plasma ferric-reducing antioxidant power and malondialdehyde did not differ significantly between groups; however, the contribution of AA to the total antioxidant capacity of plasma was approximately 50% greater in the vegetarians.

CONCLUSIONS

A long-term vegetarian diet is associated with markedly higher fasting plasma AA concentrations and lower concentrations of TAG, UA, and hsCRP. Long-term vegetarians have a better antioxidant status and coronary heart disease risk profile than do apparently healthy omnivores. Plasma AA may act a useful marker of overall health status.

Effects of a low-fat vegan diet and a Step II diet on macro- and micronutrient intakes in overweight postmenopausal women

OBJECTIVE

This study investigated the nutrient intake of overweight postmenopausal women assigned to a low-fat vegan diet or a Step II diet.

METHODS

Fifty-nine overweight (body mass index, 26 to 44 kg/m2) postmenopausal women were randomly assigned to a self-selected low-fat vegan or a National Cholesterol Education Program Step II diet in a 14-wk controlled trial on weight loss and metabolism. Nutrient intake, which was measured per 1000 kcal, was the main outcome measure. Statistical analyses included within-group and between-group t tests examining changes associated with each diet.

RESULTS

Consumption of a low-fat vegan diet was associated with greater decreases in fat, saturated fat, protein, and cholesterol intakes and greater increases in carbohydrate, fiber, beta-carotene, and total vitamin A intakes than was a Step II diet. The low-fat vegan group also increased thiamin, vitamin B6, and magnesium intakes more than the Step II group, and both groups increased folic acid, vitamin C, and potassium intakes. If considering only food sources of micronutrients, the low-fat vegan group decreased vitamin D, vitamin B12, calcium, selenium, phosphorous, and zinc intakes compared with baseline. However, with incidental supplements included, decreases were evident only in phosphorous and selenium intakes. No micronutrient decreases were found in the Step II group.

CONCLUSIONS

Individuals on a low-fat vegan or Step II diet should take steps to meet the recommended intakes of vitamin D, vitamin K, folic acid, calcium, magnesium, and zinc. Individuals on a low-fat vegan diet should also ensure adequate intakes of vitamin B12, phosphorous, and selenium.

Acceptability of a Low-fat Vegan Diet Compares Favorably to a Step II Diet in a Randomized, Controlled Trial

PURPOSE

This study aimed to assess the acceptability of a low-fat vegan diet, as compared with a more typical fat-modified diet, among overweight and obese adults.

METHODS

Through newspaper advertisements, 64 overweight, postmenopausal women were recruited, 59 of whom completed the study. The participants were assigned randomly to a low-fat vegan diet or, for comparison, to a National Cholesterol Education Program Step II (NCEP) diet. At baseline and 14 weeks later, dietary intake, dietary restraint, disinhibition, and hunger, as well as the acceptability and perceived benefits and adverse effects of each diet were assessed.

RESULTS

Dietary restraint increased in the NCEP group (P <.001), indicating a greater subjective sense of constraint with regard to diet requirements, but was unchanged in the vegan group. Disinhibition and hunger scores fell in each group (P <.001 and P <.01, respectively). The acceptability of both diets was high, although the vegan group participants rated their diet as less easy to prepare than their usual diets (P <.05) and the NCEP participants foresaw continuation of their assigned diet to be more difficult than continuation of their baseline diets (P <.05). There were no between-group differences on any acceptability measures.

CONCLUSIONS

The acceptability of a low-fat vegan diet is high and not demonstrably different from that of a more moderate low-fat diet among well-educated, postmenopausal women in a research environment.

Association between vegetarian diet and menstrual problems in young women: a case presentation and brief review

In the last twenty years, several studies have suggested the existence of an association between vegan diets and adolescent menstrual disorders. We share our experience with this problem and a review of the literature on the subject. We conclude that despite the existence of some evidence to the possible association between vegetarian diet and menstrual disorders, it is still not clear if this association is due solely to the vegetarian diet or due to the overall inadequate nutrition with decreased proportions of fat and protein in the diet. We believe that more prospective, well controlled studies are needed to truly explain this association.

The contribution of vegetarian diets to health and disease: a paradigm shift?

Advances in nutrition research during the past few decades have changed scientists' understanding of the contribution of vegetarian diets to human health and disease. Diets largely based on plant foods, such as well-balanced vegetarian diets, could best prevent nutrient deficiencies as well as diet-related chronic diseases. However, restrictive or unbalanced vegetarian diets may lead to nutritional deficiencies, particularly in situations of high metabolic demand. If some vegetarian diets are healthier than diets largely based on animal products, this constitutes an important departure from previous views on dietary recommendations to prevent disease conditions. Based on different paradigms, 3 models are presented depicting the population health risks and benefits of vegetarian and meat-based diets. This series of models encapsulates the evolution of scientific understanding on the overall effects of these dietary patterns on human health. Recent scientific advances seem to have resulted in a paradigm shift: diets largely based on plant foods, such as well-balanced vegetarian diets, are viewed more as improving health than as causing disease, in contrast with meat-based diets.

Nutrition ecology: the contribution of vegetarian diets

Nutrition ecology is an interdisciplinary scientific discipline that encompasses the entire nutrition system, with special consideration of the effects of nutrition on health, the environment, society, and the economy. Nutrition ecology involves all components of the food chain, including production, harvesting, preservation, storage, transport, processing, packaging, trade, distribution, preparation, composition, and consumption of food, as well as disposal of waste materials. Nutrition ecology has numerous origins, some of which go back to antiquity. The introduction of industrialized agriculture and mass animal production gave rise to various negative influences on the environment and health. Food quality is determined in part by the quality of the environment. The environment, in turn, is influenced by food consumption habits. Research shows that vegetarian diets are well suited to protect the environment, to reduce pollution, and to minimize global climate changes. To maximize the ecologic and health benefits of vegetarian diets, food should be regionally produced, seasonally consumed, and organically grown. Vegetarian diets built on these conditions are scientifically based, socially acceptable, economically feasible, culturally desired, sufficiently practicable, and quite sustainable.

Bioavailability of iron, zinc, and other trace minerals from vegetarian diets

Iron and zinc are currently the trace minerals of greatest concern when considering the nutritional value of vegetarian diets. With elimination of meat and increased intake of phytate-containing legumes and whole grains, the absorption of both iron and zinc is lower with vegetarian than with nonvegetarian, diets. The health consequences of lower iron and zinc bioavailability are not clear, especially in industrialized countries with abundant, varied food supplies, where nutrition and health research has generally supported recommendations to reduce meat and increase legume and whole-grain consumption. Although it is clear that vegetarians have lower iron stores, adverse health effects from lower iron and zinc absorption have not been demonstrated with varied vegetarian diets in developed countries, and moderately lower iron stores have even been hypothesized to reduce the risk of chronic diseases. Premenopausal women cannot easily achieve recommended iron intakes, as modified for vegetarians, with foods alone; however, the benefit of routine iron supplementation has not been demonstrated. It may be prudent to monitor the hemoglobin of vegetarian children and women of childbearing age. Improved assessment methods are required to determine whether vegetarians are at risk of zinc deficiency. In contrast with iron and zinc, elements such as copper appear to be adequately provided by vegetarian diets. Although the iron and zinc deficiencies commonly associated with plant-based diets in impoverished nations are not associated with vegetarian diets in wealthier countries, these nutrients warrant attention as nutritional assessment methods become more sensitive and plant-based diets receive greater emphasis.

Achieving optimal essential fatty acid status in vegetarians: current knowledge and practical implications

Although vegetarian diets are generally lower in total fat, saturated fat, and cholesterol than are nonvegetarian diets, they provide comparable levels of essential fatty acids. Vegetarian, especially vegan, diets are relatively low in alpha-linolenic acid (ALA) compared with linoleic acid (LA) and provide little, if any, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Clinical studies suggest that tissue levels of long-chain n-3 fatty acids are depressed in vegetarians, particularly in vegans. n-3 Fatty acids have numerous physiologic benefits, including potent cardioprotective effects. These effects have been demonstrated for ALA as well as EPA and DHA, although the response is generally less for ALA than for EPA and DHA. Conversion of ALA by the body to the more active longer-chain metabolites is inefficient: < 5-10% for EPA and 2-5% for DHA. Thus, total n-3 requirements may be higher for vegetarians than for nonvegetarians, as vegetarians must rely on conversion of ALA to EPA and DHA. Because of the beneficial effects of n-3 fatty acids, it is recommended that vegetarians make dietary changes to optimize n-3 fatty acid status.

Disgust sensitivity and meat consumption: a test of an emotivist account of moral vegetarianism

Emotivist perspectives on moral reasoning hold that emotional reactions precede propositional reasoning. Published findings indicate that, compared with health vegetarians, those who avoid meat on moral grounds are more disgusted by meat [Psychol. Sci. 8 (1997) 67]. If, as per emotivist perspectives, such disgust precedes moral rationales for meat avoidance, then the personality trait of disgust sensitivity should generally be inversely related to meat eating. We surveyed 945 adults regarding meat consumption, reasons for meat avoidance, and disgust sensitivity. Contrary to the emotivist prediction, (a) meat consumption was positively correlated with disgust sensitivity, and (b) individuals who reported avoiding meat for moral reasons were not more sensitive to disgust than those who avoided meat for other reasons. We conclude that moral vegetarianism conforms to traditional explanations of moral reasoning, i.e. moral vegetarians' disgust reactions to meat are caused by, rather than causal of, their moral beliefs.

Benefits and barriers to the consumption of a vegetarian diet in Australia

OBJECTIVE

The aim of this study was to examine consumers' perceived benefits and barriers to the consumption of a vegetarian diet.

DESIGN

Survey (written questionnaire) that included questions on perceived benefits and barriers to the consumption of a vegetarian diet.

SETTING

South Australia.

SUBJECTS

Six hundred and one randomly selected South Australians.

RESULTS

The main perceived barriers to adopting a vegetarian diet were enjoying eating meat and an unwillingness to alter eating habits. This was the case for men, women and all age groups, although there were sex and age differences present in over half of the barrier items. For example, family food preferences were a greater problem for women than for men, while the oldest group was more likely to agree that humans are 'meant' to eat meat than the younger groups. The main benefits associated with vegetarian diets were health benefits: increased fruit and vegetable intake, decreased saturated fat intake, weight control. Animal welfare-related benefits and disease prevention were also important. Age and sex differences were apparent, although age differences were more important than sex differences.

CONCLUSIONS

The majority of respondents perceived there to be health benefits associated with the consumption of a vegetarian diet, but also, predictably, enjoyed eating meat. Given this, it is likely that interest in plant-based diets that contain some meat is higher than that in no-meat diets. An understanding of the perceived benefits and barriers of consuming a vegetarian diet will allow the implementation of strategies to influence meat and vegetarianism beliefs, dietary behaviour and, hence, public health.

Recommendations by health organizations for pulse consumption

The present paper aims to study why and how health organizations recommend the consumption of pulses such as beans, chickpeas or lentils. Although it is recognized that frequent pulse consumption may reduce serum cholesterol levels and helps reduce risks of coronary heart disease and diabetes, these advantages are scarcely mentioned by health-promoting associations, i.e. vegetarians and organizations helping people to reduce the risks for chronic diseases. Pulses, especially common beans, are rather considered as whole grains that provide plenty of proteins, starch, dietary fibres, minerals and vitamins. Many organizations refer to the food guide pyramid to advise their members, and place beans either in the third part, together with meat, in the second one with fruits and vegetables, or in the bottom part with starchy foods. Whatever their place, they have acquired the status of staple food for anyone who wants to eat a healthy diet.

Vegetarian lifestyle and monitoring of vitamin B-12 status

Vegetarians are at risk to develop deficiencies of some essential nutrients, especially vitamin B-12 (cobalamin). Cobalamin occurs in substantial amounts only in foods derived from animals and is essential for one-carbon metabolism and cell division. Low nutritional intake of vitamin B-12 may lead to negative balance and, finally, to functional deficiency when tissue stores of vitamin B-12 are depleted. Early diagnosis of vitamin B-12 deficiency seems to be useful because irreversible neurological damages may be prevented by cobalamin substitution. The search for a specific and sensitive test to diagnose vitamin B-12 deficiency is ongoing. Serum vitamin B-12 measurement is a widely applied standard method. However, the test has poor predictive value. Optimal monitoring of cobalamin status in vegetarians should include the measurement of homocysteine (HCY), methylmalonic acid (MMA), and holotranscobalamin II. Vitamin B-12 deficiency can be divided into four stages. In stages I and II, indicated by a low plasma level of holotranscobalamin II, the plasma and cell stores become depleted. Stage III is characterized by increased levels of HCY and MMA in addition to lowered holotranscobalamin II. In stage IV, clinical signs become recognizable like macroovalocytosis, elevated MCV of erythrocytes or lowered haemoglobin. In our investigations, we have found stage III of vitamin B-12 deficiency in over 60% of vegetarians, thus underlining the importance of cobalamin monitoring in this dietary group.

The cognitive contexts of beliefs about the healthiness of meat

OBJECTIVE

The overall aim of this study was to examine a variety of belief and demographic factors that are associated with the perception that meat is intrinsically unhealthy.

DESIGN

State-wide survey (written questionnaire) that included questions on meat and nutrition beliefs, perceived barriers and benefits of vegetarian diets, personal values, number of vegetarian friends and family members, and use and trust of health/nutrition/food information sources.

SETTING

South Australia.

SUBJECTS

Six hundred and one randomly selected South Australians and 106 non-randomly selected vegetarians and semi-vegetarians.

RESULTS

For all respondents considered as a group, the most important predictors of the belief that meat is intrinsically unhealthy were the perceived benefits of vegetarian diets (all positive predictors). These included: (1) the perceived links between vegetarianism, peace and increased contentment; (2) animal welfare and environmental benefits; and (3) health benefits. There were differences between different dietary groups however. For non-vegetarians, social concerns about vegetarianism (positive) were most important, followed by health and non-health benefits (positive) of vegetarianism. Red meat appreciation was the strongest (positive) predictor for vegetarians, with health benefits of vegetarianism (positive) and education (negative predictor) also important.

CONCLUSIONS

The implications of the findings for health and other issues are discussed. Judgements about the healthiness of meat are likely to be related to moral and environmental beliefs and, for non-vegetarians, to social concerns about vegetarianism, in addition to health beliefs. These need to be considered if any attempts are made to influence meat consumption.

Effects of a very low-fat, vegan diet in subjects with rheumatoid arthritis

OBJECTIVE

To demonstrate the effects of a very low-fat, vegan diet on patients with rheumatoid arthritis (RA).

DESIGN

Single-blind dietary intervention study. SUBJECTS AND STUDY INTERVENTIONS: This study evaluated the influence of a 4-week, very low-fat (approximately 10%), vegan diet on 24 free-living subjects with RA, average age, 56 +/- 11 years old.

OUTCOME MEASUREMENTS

Prestudy and poststudy assessment of RA symptomatology was performed by a rheumatologist blind to the study design. Biochemical measures and 4-day diet data were also collected. Subjects met weekly for diet instruction, compliance monitoring, and progress assessments.

RESULTS

There were significant (p < 0.001) decreases in fat (69%), protein (24%), and energy (22%), and a significant increase in carbohydrate (55%) intake. All measures of RA symptomatology decreased significantly (p < 0.05), except for duration of morning stiffness (p > 0.05). Weight also decreased significantly (p < 0.001). At 4 weeks, C-reactive protein decreased 16% (ns, p > 0.05), RA factor decreased 10% (ns, p > 0.05), while erythrocyte sedimentation rate was unchanged (p > 0.05).

CONCLUSION

This study showed that patients with moderate-to-severe RA, who switch to a very low-fat, vegan diet can experience significant reductions in RA symptoms.

Considerations in planning vegan diets: infants

Appropriately planned vegan diets can satisfy nutrient needs of infants. The American Dietetic Association and The American Academy of Pediatrics state that vegan diets can promote normal infant growth. It is important for parents to provide appropriate foods for vegan infants, using guidelines like those in this article. Key considerations when working with vegan families include composition of breast milk from vegan women, appropriate breast milk substitutes, supplements, type and amount of dietary fat, and solid food introduction. Growth of vegan infants appears adequate with post-weaning growth related to dietary adequacy. Breast milk composition is similar to that of non-vegetarians except for fat composition. For the first 4 to 6 months, breast milk should be the sole food with soy-based infant formula as an alternative. Commercial soymilk should not be the primary beverage until after age 1 year. Breastfed vegan infants may need supplements of vitamin B-12 if maternal diet is inadequate; older infants may need zinc supplements and reliable sources of iron and vitamins D and B-12. Timing of solid food introduction is similar to that recommended for non-vegetarians. Tofu, dried beans, and meat analogs are introduced as protein sources around 7-8 months. Vegan diets can be planned to be nutritionally adequate and support growth for infants.

Considerations in planning vegan diets: children

This article reviews research on the growth and nutrient intake of vegan children and provides guidelines for counselling parents of vegan children. Although diets of vegan children meet or exceed recommendations for most nutrients, and vegan children have higher intakes of fiber and lower intakes of total fat, saturated fat, and cholesterol than omnivore children, some studies indicate that they may be low in calcium. In addition, bioavailability of zinc and iron from plant foods can be low. Protein needs are slightly higher for vegan children but are easily met with a varied diet that provides adequate energy. Special attention should be given to dietary practices that enhance absorption of zinc and iron from plant foods. Further, good sources of the omega-3 fatty acid linolenic acid should be emphasized to enhance synthesis of the long-chain fatty acid docosahexanoic acid. Dietetics professionals who counsel vegan families should help parents identify good sources of vitamin B-12, riboflavin, zinc, calcium and, if sun exposure is not adequate, vitamin D. This should not be problematic, due to the growing number and availability of fortified vegan foods that can help children meet all nutrient needs. Therefore, with appropriate food choices, vegan diets can be adequate for children at all ages.

Influences on meat consumption in Australia

In a study of influences on meat consumption, over 700 South Australians answered questions on frequency of meat consumption, beliefs about meat and nutrition, perceived difficulties with and benefits of vegetarian diets, personal values, number of vegetarian significant others, use in and trust of health/nutrition/food information sources, and demography. Perceived difficulties with vegetarian diets, the number of vegetarian significant others and beliefs about meat were important predictors of meat consumption. There were differences between men and women and members of different age groups, which should be taken into account when attempts are made to influence meat consumption. For example, health promotion campaigns that focus on whether or not meat is necessary in the diet may influence meat consumption, but would be most successful if directed predominantly at older people and men. In contrast, the meat consumption of women and younger people was strongly associated with more specific concerns about lack of iron and protein in the vegetarian diet. Some of the difficulties people find with vegetarian diets will also apply to plant-based diets generally, and such diets are becoming more widely acknowledged as providing health benefits. Therefore, the findings have important implications for public health.

Joint Position Statement: nutrition and athletic performance. American College of Sports Medicine, American Dietetic Association, and Dietitians of Canada

It is the position of the American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine that physical activity, athletic performance, and recovery from exercise are enhanced by optimal nutrition. These organizations recommend appropriate selection of food and fluids, timing of intake, and supplement choices for optimal health and exercise performance. This position paper reviews the current scientific data related to the energy needs of athletes, assessment of body composition, strategies for weight change, the nutrient and fluid needs of athletes, special nutrient needs during training, the use of supplements and nutritional ergogenic aids, and the nutrition recommendations for vegetarian athletes. During times of high physical activity, energy and macronutrient needs-especially carbohydrate and protein intake-must be met in order to maintain body weight, replenish glycogen stores, and provide adequate protein for building and repair of tissue. Fat intake should be adequate to provide the essential fatty acids and fat-soluble vitamins, as well as to help provide adequate energy for weight maintenance. Overall, diets should provide moderate amounts of energy from fat (20% to 25% of energy); however, there appears to be no health or performance benefit to consuming a diet containing less than 15% of energy from fat. Body weight and composition can affect exercise performance, but should not be used as the sole criterion for sports performance; daily weigh-ins are discouraged. Consuming adequate food and fluid before, during, and after exercise can help maintain blood glucose during exercise, maximize exercise performance, and improve recovery time. Athletes should be well-hydrated before beginning to exercise; athletes should also drink enough fluid during and after exercise to balance fluid losses. Consumption of sport drinks containing carbohydrates and electrolytes during exercise will provide fuel for the muscles, help maintain blood glucose and the thirst mechanism, and decrease the risk of dehydration or hyponatremia. Athletes will not need vitamin and mineral supplements if adequate energy to maintain body weight is consumed from a variety of foods. However, supplements may be required by athletes who restrict energy intake, use severe weight-loss practices, eliminate one or more food groups from their diet, or consume high-carbohydrate diets with low micronutrient density. Nutritional ergogenic aids should be used with caution, and only after careful evaluation of the product for safety, efficacy, potency, and whether or not it is a banned or illegal substance. Nutrition advice, by a qualified nutrition expert, should only be provided after carefully reviewing the athlete's health, diet, supplement and drug use, and energy requirements.

Position of the American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and athletic performance

It is the position of the American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine that physical activity, athletic performance, and recovery from exercise are enhanced by optimal nutrition. These organizations recommend appropriate selection of food and fluids, timing of intake, and supplement choices for optimal health and exercise performance. This position paper reviews the current scientific data related to the energy needs of athletes, assessment of body composition, strategies for weight change, the nutrient and fluid needs of athletes, special nutrient needs during training, the use of supplements and nutritional ergogenic aids, and the nutrition recommendations for vegetarian athletes. During times of high physical activity, energy and macronutrient needs--especially carbohydrate and protein intake--must be met in order to maintain body weight, replenish glycogen stores, and provide adequate protein for building and repair of tissue. Fat intake should be adequate to provide the essential fatty acids and fat-soluble vitamins, as well as to help provide adequate energy for weight maintenance. Overall, diets should provide moderate amounts of energy from fat (20% to 25% of energy); however, there appears to be no health or performance benefit to consuming a diet containing less than 15% of energy from fat. Body weight and composition can affect exercise performance, but should not be used as the sole criterion for sports performance; daily weigh-ins are discouraged. Consuming adequate food and fluid before, during, and after exercise can help maintain blood glucose during exercise, maximize exercise performance, and improve recovery time. Athletes should be well-hydrated before beginning to exercise; athletes should also drink enough fluid during and after exercise to balance fluid losses. Consumption of sport drinks containing carbohydrates and electrolytes during exercise will provide fuel for the muscles, help maintain blood glucose and the thirst mechanism, and decrease the risk of dehydration or hyponatremia. Athletes will not need vitamin and mineral supplements if adequate energy to maintain body weight is consumed from a variety of foods. However, supplements may be required by athletes who restrict energy intake, use severe weight-loss practices, eliminate one or more food groups from their diet, or consume high-carbohydrate diets with low micronutrient density. Nutritional ergogenic aids should be used with caution, and only after careful evaluation of the product for safety, efficacy, potency, and whether or not it is a banned or illegal substance. Nutrition advice, by a qualified nutrition expert, should only be provided after carefully reviewing the athlete's health, diet, supplement and drug use, and energy requirements.

Update of nutrition guidelines for the teen: trends and concerns

Sociocultural influences are known to affect adolescent eating patterns and behaviors. Some teens reject a meat-based diet to become vegetarians; others take up dieting to lose weight or develop an eating disorder. Teens require increased nutrients to provide for the accelerated growth that takes place during these years. Nutritional deficiencies in adolescence can lead to loss of height, osteoporosis, and delayed sexual maturation. Sports also play an important role in many teens' lives. The desire to excel can lead to increased training and prolonged periods of dieting. Disordered eating, amenorrhea, and osteoporosis describe the "female athlete triad." Although more frequently seen in girls, boys who participate in sports that have an emphasis on size and weight such as wrestling and body building are also at risk for subclinical eating disorders. This paper discusses issues surrounding restrictive and nonrestrictive food patterns of adolescents and their nutritional consequences.