Vegetarianism, depression, and the five factor model of personality

Personality, self-knowledge, and meat reduction intentions

OBJECTIVE

Meat consumption has a host of serious negative consequences for nonhuman animals, underprivileged humans, and the natural environment. Several interventions have been developed to encourage meat reduction but to relatively limited effect. There is also a range of established predictors of meat consumption, but much less is known about the factors that predict intentions to reduce meat consumption. The goal of this study was to determine the roles of personality and self-knowledge in meat reduction intentions.

METHOD

In this set of three preregistered studies, we tested brief interventions to encourage meat reduction intentions and examined personality predictors of intentions to reduce meat consumption.

RESULTS

We found no evidence that brief interventions with or without a self-knowledge component had a meaningful effect on changing meat reduction intentions. However, we found robust evidence for relatively small associations between intending to eat less meat and high Openness to Experience, high Emotionality, and perceiving meat reduction as moral behaviors.

CONCLUSION

Individual differences may be a more influential predictor of meat reduction intentions than brief interventions. Implications for promoting meat reduction are discussed.

Human gut microbiome, diet, and mental disorders

Diet is one of the most important external factor shaping the composition and metabolic activities of the gut microbiome. The gut microbiome plays a crucial role in host health, including immune system development, nutrients metabolism, and the synthesis of bioactive molecules. In addition, the gut microbiome has been described as critical for the development of several mental disorders. Nutritional psychiatry is an emerging field of research that may provide a link between diet, microbial function, and brain health. In this study, we have reviewed the influence of different diet types, such as Western, Mediterranean, vegetarian, and ketogenic, on the gut microbiota composition and function, and their implication in various neuropsychiatric and psychological disorders.

The perceived experience of adhering to vegan diet: a descriptive phenomenological study

BACKGROUND

Today, raw vegetarianism is considered one of the most important socio-cultural developments in contemporary societies. In this regard, the present study was conducted to describe the perceived experience of people adhering to a vegan diet through a phenomenological perspective.

METHODS

This qualitative study explores the perceived experiences of individuals who follow a vegan diet and are part of the self-care campaign in Kermanshah, Iran. sampling was purposeful and face-to-face interviews were conducted with 12 individuals who follow a vegan lifestyle. The data were analyzed after being collected using the seven steps of Collizi. MAXQUDA software (version 12) was used for data management.

RESULTS

After qualitative data analysis, we identified 567 codes, which were categorized into 15 sub-themes. From these sub-themes, we derived 4 main themes. The main themes include: In pursuit of redemption (Meaningful framework, In awareness path, Unequaled Disappointment, Chronic and complex conditions), Seeking the New World (Starting with doubt and hesitation, The temptation to return, Constant criticism, Unfamiliar appearance), On the path of overcoming difficulties (Associate problems, Matching the new way, Perceived recommendations), and attaining the expected outcomes (Healthy lifestyle, Therapeutic feedback, Enhancing emotional wellbeing, Feeling of youth).

CONCLUSION

Based on the participants' experience, despite the challenging journey, the people with a vegetarian diet experienced partial and complete improvement of all the symptoms of the diseases. They had a healthy lifestyle and felt young and energetic. Likewise, this method had a positive effect on people's mental state and mood.

Eating vegan due to cancer: A different social experience than other vegan dieters?

Many diagnosed with cancer change their diet in response to the diagnosis, with a vegan diet being a common choice. There may be health benefits to this, but research has demonstrated that following a vegan diet can have negative social ramifications. These social ramifications seem to be experienced to a lesser extent by those who following a vegan diet for health versus moral reasons, but this is a heterogeneous group; people may choose the diet for a myriad of different health reasons. In two pre-reregistered studies, we examined the social experience of those who adopt a vegan diet following a cancer diagnosis. Study 1, an experimental study, demonstrated that omnivores responded more positively to a friend who was vegan for cancer reasons than animal or general health reasons, which was explained by increased empathy. In Study 2, a cross-sectional survey study, those who adopted a vegan diet due to cancer reported (overall) less negative social experiences than those following a vegan diet more generally. These participants reported that cancer represented a greater social challenge than their diet. Taken together, these findings suggest that "vegan due to cancer" is a unique social identity and a unique social experience, relative to that of those motivated by other reasons, including general health reasons.

Vegetarianism and eating disorders: The subjective experience of healthcare professionals

Vegetarianism is growing dramatically among adolescents and young adults. Professionals specialized in eating disorders (ED) may routinely face patients adhering to these popular vegetarian practices. This qualitative study aimed to investigate healthcare professionals' subjective experience of vegetarianism in ED patients. Interviews of practitioners specialized in ED, recruited from the French federation of anorexia and bulimia (FFAB), were conducted using a semi-structured guide. We reached data saturation. Thematic analysis was used to identify and analyze patterns of meaning in the dataset. Eighteen professionals (dieticians, physician-nutritionists, and a psychiatrist) with private or institutional practices were interviewed. Three meta-themes emerged from our thematic analysis: (1) heterogeneous perceptions of vegetarianism among healthcare professionals, (2) diverse nutritional care practices, (3) factors influencing professionals' nutritional strategies and approaches. This original qualitative and exploratory study reported vegetarianism is a fast-growing phenomenon observed in a majority of adolescent patients with anorexia nervosa, with various underlying motivations reported. In all cases, the nature of the timing and relation between the vegetarian practices and the ED should be carefully assessed, using specific tools. Because of the ethical dimension of this issue and the risk of professional bias, institutional policy based on specific practice guidelines, to be developed, are strongly encouraged.

Meta-analysis of personality trait differences between omnivores, vegetarians, and vegans

Vegetarian and vegan diets have been increasing in the Western world. Recent research has focused on personality trait differences between dietary groups, in part because personality traits are broad characteristics that can integrate findings about different factors that motivate vegetarian or vegan diets. Previous research on personality predictors of vegetarian and vegan (veg*n) diet, however, has yielded inconsistent results. The goal of this study was to integrate the existing results of Big Five personality differences between veg*ns and omnivores as well as between vegetarians and vegans. To this end, we meta-analyzed data from 15 studies and N = 69,576 individuals from several countries. Results indicated that veg*ns were significantly higher in Openness (d = 0.40) and Agreeableness (d = 0.17) than omnivores, while vegans were significantly higher in Openness (d = 0.14) than vegetarians. This work isolates Openness and Agreeableness as important trait predictors of plant-based diets and sets the stage for future work on the factors that motivate vegetarian or vegan diet. Personality traits can provide an integrative framework for conceptualizing dietary preferences, be used to make predictions about the sources, course and correlates of dietary choices, and potentially be useful for advocates and policymakers seeking to tailor meat-reduction interventions.

Vegan diet: nutritional components, implementation, and effects on adults' health

Vegan diet has emerged as a popular dietary choice for people worldwide in recent times, due to concerns such as health issues, animal rights and welfare, and the sustainability of the environment. The purpose of this literature review was to explain how a vegan diet may affect the health of adults and to point out beneficial components found in it as well as any difficulties associated with its implementation. Evidence supports that a vegan diet can reduce the risk of chronic diseases, such as type 2 diabetes, hypertension, and certain types of cancer. A well-planned vegan diet must include adequate calories and nutrients, as well as the necessary supplements, such as vitamin B12, vitamin D and EPA/DHA. Given the current growing interest in plant-based diets among the general population, it is crucial to understand both the barriers, risks, and benefits of the vegan diet among physicians, policy makers, and the general population.

Determinants of Depressive Symptoms Among Patients with Rheumatoid Arthritis in China: A Structural Equation Model

Background

This study aimed to examine how personality traits, social support and clinical features including pain, disease activity, functional status, sleep quality, and fatigue influence on depressive symptoms in Chinese rheumatoid arthritis (RA) patients.

Methods

This study was conducted from November, 2022 to June, 2023 among Chinese RA patients. Pain, disease activity, functional status, sleep quality, fatigue, social support, personality traits, and depressive symptoms were assessed. The following relationships among three hypotheses were analyzed by structural equation model (SEM): H1: clinical features have a direct effect on depressive symptoms; H2: personality traits might work as a mediator between clinical features and depression; H3: social support is related to depressive symptoms, being a direct effect or an indirect effect through clinical features or personality traits.

Results

The final model including 326 RA patients presented a good fit (χ2=103, χ2/df=1.69; GFI=0.96; AGFI=0.93; CFI=0.97; TLI=0.96; RMSEA=0.046). Clinical features had a total effect of 0.59 on depressive symptoms, of which β=0.33 (P=0.013) was an indirect effect through personality traits, indicating a mediating influence between this relationship; moreover, there was a significant direct association between clinical features and depressive symptoms (β=0.26; P=0.022). Personality traits (β=-0.65; P<0.001) had a much stronger relation with depressive symptoms than with clinical features. Social support had a total effect of 0.81 on personality traits, being a direct effect of β=0.52 (P<0.001) and an indirect effect of β=0.29 (P<0.001) through clinical features. The final proposed model explained 77% of the variance of depressive symptoms.

Conclusion

Personality traits had a considerable influence upon depressive symptoms, while social support seemed to have a major effect on personality traits. It is necessary to apply comprehensive assessment and interventions of patients' personality traits, clinical features, as well as social support, which could optimize their mental health.

Personality, dietary identity, mental and sleep health in vegans and vegetarians: A preliminary cross-sectional study

Background and Aims

Plant-based diets have gained popularity over the past decade. However, research regarding mental and sleep health benefits of following plant-based diets are conflicting. As there are associations between mental/sleep health and various personality traits, and personality may differ between individuals who follow different diets, in this preliminary study, we examined the associations between mental and sleep health and (i) personality and (ii) dietary identity in individuals who follow vegan and vegetarian diets.

Methods

Cross-sectional data on sociodemographic, personality traits, dietarian identity, overall mental health, depression, anxiety, stress, and sleep quality were collected from 57 vegan/vegetarian participants between the ages of 18-40.

Results

After controlling for various sociodemographic and lifestyle factors, linear regression models revealed that (i) higher dietarian private regard was a significant predictor of better overall mental health, (ii) lower levels of extraversion and higher levels of empathy predicted depression, (iii) higher levels of neuroticism and empathy predicted anxiety, (iv) higher levels of neuroticism, dietarian centrality, and neuroticism × centrality predicted stress, (v) higher levels of conscientiousness, lower levels of dietarian centrality, but higher levels of personal motivation and dietary strictness, as well as conscientiousness × centrality, conscientiousness × personal motivation, and conscientiousness × strictness predicted better sleep quality.

Conclusions

These preliminary findings suggest that not only personality traits, but also dietary identity was indeed related to mental and sleep health in individuals who follow plant-based diets.

Knowledge, attitudes, and factors associated with vegetarianism in the Saudi Population

BACKGROUND

In recent years, there has been great interest in the dietary practices of vegetarians in addition to an increasing awareness of the potential benefits of vegetarian diets. However, there are insufficient data on the spread of vegetarianism in Arab countries. The aim of this study was to investigate knowledge and attitudes about vegetarianism and associated factors in the Saudi population and to understand the reasons for its growing prevalence.

METHOD

This is a cross-sectional study began in May 2020 and ended in September 2020. Researchers distributed the questionnaire electronically through social media. Data were collected electronically and exported to Excel by the researchers .The electronic questionnaire comprised three sections: sociodemographic questions, reasons for following a vegetarian diet, and beliefs and knowledge about vegetarianism.

RESULTS

There were 3,035 responses, of which 80.2% of respondents were female and 19.8% were male. Participant were aged 18-65. Vegetarians represented 37.5% (15.7% semivegetarians, 8.1% pescovegetarians, 64.3% lacto-ovo-vegetarians, and 11.3% vegans), and the rest were nonvegetarians. The majority of the vegetarian participants (92.9%) had a low vegetarianism knowledge level. Health issues, followed by ethical and environmental concerns, were the most common motivators for adopting a vegetarian diet; these reasons were cited by 72.5%, 59.3%, and 47.9% of participants, respectively. Factors associated with increased vegetarianism were engaging in exercise for half an hour to two hours, while factors associated with decreased vegetarianism were male, aged 51-64 years, being married, having a higher education, working in the health sector, being a housewife, and having an income between 5,000 and 10,000 SR/month.

CONCLUSION

Vegetarianism appears to be a growing phenomenon among the Saudi population. Increased awareness of health issues and the desire to live a healthy lifestyle might be the strongest motives. This study offers an opportunity to better understand vegetarianism in Saudi Arabia along with the possibility of expanding vegetarian food choices for the general public.

Plant-based and vegetarian diets: an overview and definition of these dietary patterns

PURPOSE

This paper aims to present an overview of the definitions of "plant-based and "vegetarian diets" adopted by different organizations worldwide, proposing new standard definitions and discussing the notion of vegetarianism as a restrictive dietary pattern.

METHODS

An extensive literature review on the different definitions of vegetarian and plant-based diets was conducted. Definitions of different international vegetarian and vegan organizations were also taken into account. Objective definitions for vegetarian and plant-based diets, as well as for their subcategories, were proposed. Other aspects related to how vegetarian diets are viewed and defined were also discussed.

RESULTS

We proposed that a vegetarian diet should be defined as "a dietary pattern that excludes meat, meat-derived foods, and, to different extents, other animal products". This definition would include, among others, ovolactovegetarian and vegan diets. The proposed definition for a plant-based diet was "a dietary pattern in which foods of animal origin are totally or mostly excluded". Other types of diets, such as flexitarian and pescetarian diets, could be considered plant-based. A vegetarian diet should not be considered restrictive. Instead, terms such as alternative or non-conventional could be used to define it and to distinguish it from the conventional diet adopted by most of the Western population.

CONCLUSION

This paper was able to elaborate objective definitions of vegetarian and plant-based diets. Standardizing nomenclatures may reduce misinterpretation and confusion in this field of study.

Moral emotions and justifying beliefs about meat, fish, dairy and egg consumption: A comparative study of dietary groups

Meat eaters and meat abstainers differ in their beliefs and moral emotions related to meat consumption alongside gender differences. Few studies have investigated beliefs and moral emotions in pescatarians and vegans. Little is known about differences in moral emotions and beliefs regarding dairy, eggs, and fish or about speciesist beliefs within and between specific dietary groups. To address this gap, we investigated moral emotions (consumption-related disgust and guilt), attitudes towards animals (Animal Attitudes Scale) and justifying beliefs related to meat (Carnism Inventory), dairy, egg, and fish consumption in omnivores (n = 167), pescatarians (n = 110), vegetarians (n = 116), and vegans (n = 149). Results showed that people who consumed animal-derived products reported lower disgust and guilt and held stronger justifying beliefs about consumption of these products than those who did not consume animal products. All dietary groups significantly differed from each other in their attitudes about using animals for human benefit, with omnivores showing the least positive attitudes towards animals, followed by pescatarians and vegetarians, and with vegans showing the most positive attitudes towards animals. Women experienced greater moral emotions and held fewer justifying beliefs than men within groups where animal products were consumed and related to the animal-based products they consume (i.e., fish for pescatarians and eggs/dairy for vegetarians). These findings emphasise the importance of considering a wider range of animal products, such as eggs, dairy and fish, and dietary groups in order to obtain a comprehensive understanding of the psychological underpinnings of animal product consumption. The results highlight differences between dietary groups in attitudes and moral concern towards animals, which may be important to consider when designing interventions to reduce animal product consumption.

The Association between Vegan, Vegetarian, and Omnivore Diet Quality and Depressive Symptoms in Adults: A Cross-Sectional Study

Dietary patterns and depressive symptoms are associated in cross-sectional and prospective-designed research. However, limited research has considered depression risk related to meat-based and plant-based dietary patterns. This study explores the association between diet quality and depressive symptoms across omnivore, vegan, and vegetarian dietary patterns. A cross-sectional online survey utilised the Dietary Screening Tool (DST) and the Centre for Epidemiological Studies of Depression Scale (CESD-20) to measure diet quality and depressive symptoms, respectively. A total of 496 participants identified as either omnivores (n = 129), vegetarians (n = 151), or vegans (n = 216). ANOVA with Bonferroni post hoc corrections indicates that dietary quality was significantly different between groups F(2, 493) = 23.61, p < 0.001 for omnivores and vegetarians and omnivores and vegans. Diet quality was highest in the vegan sample, followed by vegetarian and omnivore patterns. The results show a significant, moderately negative relationship between higher diet quality and lower depressive symptoms (r = -0.385, p < 0.001) across groups. Hierarchical regression showed that diet quality accounted for 13% of the variability in depressive symptoms for the omnivore sample, 6% for vegetarians, and 8% for vegans. This study suggests that diet quality in a meat-based or plant-based diet could be a modifiable lifestyle factor with the potential to reduce the risk of depressive symptoms. The study indicates a greater protective role of a high-quality plant-based diet and lower depressive symptoms. Further intervention research is needed to understand the bi-directional relationship between diet quality and depressive symptoms across dietary patterns.

Dietary Habits and Lifestyle, Including Cardiovascular Risk among Vegetarians and Omnivores during the COVID-19 Pandemic in the Polish Population

Background: This study assessed how two food groups—omnivores (OMN) and vegetarians (VEGE)—differ in lifestyle changes, including dietary habits during the COVID-19 pandemic. Materials: A total of 861 persons participated in the survey and were divided into two groups: persons following a mixed diet (n = 489) and vegetarians, including vegans (n = 372). The mean age shows no significant differences. Methods: An online survey was conducted on the Polish population during the COVID-19 pandemic. Data was collected using social media; the survey was intended for adults and included separate sheets for different diets (OMN vs. VEGE). Results: The results in both groups were similar regarding the burden of premature diseases. Most respondents (~90%) did not indicate cardiovascular disease abnormalities. In the OMN group, overweight and obesity occurred more often, and the OMN group also showed a higher percentage of people reporting weight gain (OMN 42.7% vs. VEGE 35.9%). The results disclosed the VEGE group significantly more frequently chose products, i.e., vegetables (p = 0.029), legumes (p < 0.001), and dairy products or their plant substitutes (p = 0.002), compared to the OMN group. Conclusions: The VEGE group revealed the most regularities in dietary habits during the pandemic.

Exploring user-generated content related to vegetarian customers in restaurants: An analysis of online reviews

This study aimed to explore and evaluate factors that impact the dining experience of vegetarian consumers within a range of vegetarian-friendly restaurants. To explore the factors and understand consumer experience, this study analyzed a vast number of user-generated contents of vegetarian consumers, which have become vital sources of consumer experience information. This study utilized machine-learning techniques and traditional methods to examine 54,299 TripAdvisor reviews of approximately 1,008 vegetarian-friendly restaurants in London. The study identified 21 topics that represent a holistic opinion influencing the dining experience of vegetarian customers. The results suggested that "value" is the most popular topic and had the highest topic percentage. The results of regression analyses revealed that five topics had a significant impact on restaurant ratings, while 12 topics had negative impacts. Restaurant managers who pay close attention to vegetarian aspects may utilize the findings of this study to satisfy vegetarian consumer requirements better and enhance service operations.

Association between meatless diet and depressive episodes: A cross-sectional analysis of baseline data from the longitudinal study of adult health (ELSA-Brasil)

BACKGROUND

The association between vegetarianism and depression is still unclear. We aimed to investigate the association between a meatless diet and the presence of depressive episodes among adults.

METHODS

A cross-sectional analysis was performed with baseline data from the ELSA-Brasil cohort, which included 14,216 Brazilians aged 35 to 74 years. A meatless diet was defined from in a validated food frequency questionnaire. The Clinical Interview Schedule-Revised (CIS-R) instrument was used to assess depressive episodes. The association between meatless diet and presence of depressive episodes was expressed as a prevalence ratio (PR), determined by Poisson regression adjusted for potentially confounding and/or mediating variables: sociodemographic parameters, smoking, alcohol intake, physical activity, several clinical variables, self-assessed health status, body mass index, micronutrient intake, protein, food processing level, daily energy intake, and changes in diet in the preceding 6 months.

RESULTS

We found a positive association between the prevalence of depressive episodes and a meatless diet. Meat non-consumers experienced approximately twice the frequency of depressive episodes of meat consumers, PRs ranging from 2.05 (95%CI 1.00-4.18) in the crude model to 2.37 (95%CI 1.24-4.51) in the fully adjusted model.

LIMITATIONS

The cross-sectional design precluded the investigation of causal relationships.

CONCLUSIONS

Depressive episodes are more prevalent in individuals who do not eat meat, independently of socioeconomic and lifestyle factors. Nutrient deficiencies do not explain this association. The nature of the association remains unclear, and longitudinal data are needed to clarify causal relationship.

Previous School Bullying-Associated Depression in Chinese College Students: The Mediation of Personality

Previous school bullying was associated with increased risk of depression in students. However, little was known about the role of the Big Five personality traits in this association. The purpose of this study was to investigate the possible mediation by the Big Five personality traits in this association in a large group of Chinese college students, and to provide help for educators to prevent students from serious psychological and mental diseases caused by school bullying. Random stratified cluster sampling was used to survey 2152 college students ranging from freshmen to seniors at three universities in Qiqihar city, Heilongjiang Province, China. The risk factors for previous school bullying included gender, living expenses per month, caregivers, parents often quarreling, and divorced parents. Males were more likely to be bullied at school than females. The influencing factors of depression include gender, caregivers, living expenses per month, frequent parents quarreling, and parental divorce. Females were more prone to depression than males. Depression was significantly correlated with all dimensions of school bullying and the Big Five personality traits (p < 0.05). The Big Five personality traits were found to play a significant mediating role between depression and school bullying in up to 45% of cases involving depression. Our major findings highlighted the promising role of personality-based intervention measures in reducing the risk of depression associated with school bullying in Chinese students.

Perceptions of Farm Animal Sentience and Suffering: Evidence from the BRIC Countries and the United States

In this study, we examined how beliefs about farm animal sentience and their suffering vary across culture and demographic characteristics. A total of N = 5027) questionnaires were administered in Brazil, Russia, India, China, and the USA. Brazilians showed higher and Chinese lower levels of perceived animal sentience. In Russia and India, the perception of suffering and sentience increases with age, with similar levels to those observed in the USA. In all the countries, more people agreed than disagreed that animals are sentient. Men in India show higher levels of agreement with the relation between eating meat and animal suffering, followed by women in Brazil and China. Lower levels of agreement are observed in Americans and Chinese. Women show higher levels of compassion than men. In Russia, there is a slightly higher level of agreement between men and in the USA younger men agree more. Young American men show higher levels of agreement, while in India and China age has the opposite effect. For fair trading competition, it is important to standardize procedures and respect the demand for both animal protein and its ethical production. Overall, our results showed that perceptions of farm animal sentience and suffering vary substantially across countries and demographic groups. These differences could have important consequences for the perceived ethicality of meat production and consumption, and for global trade in animal products.

Minor and inconsistent differences in Big Five personality traits between vegetarians and vegans

Most research examining individuals who follow different diets has combined vegetarians and vegans into a single group. To investigate whether this consolidation is justified, we analyzed possible differences between vegetarians and vegans for the Big Five personality traits in two studies. In our pre-study, we used data from a German convenience sample of 400 vegetarians and 749 vegans and found that vegans reported slightly higher scores in Openness compared to vegetarians (d = 0.22). In the preregistered main study, we used data provided by 1203 vegetarians and 128 vegans from the German Socio-Economic Panel Study; we found that vegetarians reported slightly higher scores in Neuroticism compared to vegans (d = 0.18) but did not differ in Openness. We found no differences in Conscientiousness, Extraversion, or Agreeableness in either study. Controlling for the socio-demographic variables of age, gender, and socio-economic status did not alter the pattern of results. Overall, these results suggest that there are no or only small differences in Openness or Neuroticism between vegetarians and vegans. Further studies utilizing very large, representative samples are needed to better understand the relationship between personality and diet groups.

In the Labyrinth of Dietary Patterns and Well-Being—When Eating Healthy Is Not Enough to Be Well

This paper aims to identify the relation between food consumption and well-being, and the level of well-being depending on a diet followed. Moreover, we analyze whether people driven by single motives, such as the health, pleasure or social dimension of food declare the lower or higher level of well-being than those motivated by a larger number of factors. The survey was conducted online (CAWI, n = 1067). The following scales were used: Satisfaction With Life Scale (SWLS), Satisfaction with Food-related Life Scale (SWFL), Health Taste Attitude Scales (HTAS) and Social Dimension of Food Meaning. The data analysis was carried out with the application of one-way analysis of variance (ANOVA), partial eta squared, a t-Student’s test, the Hochberg test, the Games-Howell test, and Pearson’s correlation. Levels of Subjective Well-Being (SWB) and Food Well-Being (FWB) are strongly correlated with consumers’ dietary pattern. The frequency of consumption of organic food and following vegan, low salt, and low sugar diets leads to higher levels of SWB, while FWB is additionally affected by the regular consumption of low-fat products and foods that improve one’s mood. The level of well-being is linked with the motivation to follow specific diets and attentiveness related to dietary patterns. People paying attention to the health aspects, pleasure and social dimension of food meaning show higher level of FWB than people focusing exclusively on health aspects.

Vegetarian diet and depression scores: A meta-analysis

BACKGROUND

Several studies have suggested an association between vegetarian diet and higher depression scores. However, some studies have also shown an effect in the opposite direction, indicating lower depression scores in vegetarians. Given this discrepancy in the literature, this meta-analysis was aimed to determine whether there is a significant association between vegetarian diet and depression scores across different published studies.

METHODS

A keyword search in major databases was conducted. Studies reporting depression scores in vegetarians and a non-vegetarian control group were included. Meta-analysis following a conditional random-effects procedure was conducted in R.

RESULTS

After duplicates were removed and studies were analyzed for inclusion criteria, k=13 studies with an overall n of 49889 participants (8057 vegetarians and 41832 non-vegetarian controls) were included in the analysis. Random-effects meta-analysis revealed a significant difference between vegetarians and non-vegetarians, with vegetarians showing higher depression scores than non-vegetarians.

LIMITATIONS

The heterogeneity between studies was high and geographical variation in study location was low, limiting cross-cultural insights.

CONCLUSIONS

Vegetarians show higher depression scores than non-vegetarians. However, due to high heterogeneity of published studies, more empirical research is needed before any final conclusions can be drawn. Also, empirical studies from a higher number of different countries would be desirable.

Differences Between Omnivores and Vegetarians in Personality Profiles, Values, and Empathy: A Systematic Review

Numerous medical studies have documented vegetarian diets as having various health benefits. Studies have also compared vegetarians with other dietary groups from a socio-psychological perspective. The objective of this review is to investigate the differences between vegetarians and omnivores in terms of their personality profiles, values, and empathy skills. A search was conducted across three electronic databases. Non-randomized, observational, cross-sectional, and cohort studies were eligible. Outcomes provided information about the differences between the above-mentioned dietary groups regarding their personality profiles, values, and empathy skills. A shortened version of the Newcastle–Ottawa Scale was used to assess the risk of bias for the included studies. Of the 2,513 different studies found, 25 (total number of participants n = 23,589) were ultimately included. These studies indicate that vegetarians significantly differ from omnivores in their personalities, values, and ability to be empathetic. Omnivorism is associated with an increased orientation toward social dominance, greater right-wing authoritarianism, and, in line with this, a stronger tendency to be prejudiced. Vegetarianism is associated with greater openness and empathy. The values of vegetarians are based more on universalism, hedonism, stimulation, and self-direction, whereas the values of omnivores are based more on the idea of power. To answer a narrowly defined and clear question, issues such as animal ethics, animal rights, and environmental protection are not considered in this review. The findings of this review, showing marked differences in personality correlating to the choice of diet and the increasing influence of plant-based diets on a global level, indicate that further studies about vegetarianism are warranted.

Plant-based dietary quality and depressive symptoms in Australian vegans and vegetarians: a cross-sectional study

Plant-based dietary patterns (vegan and vegetarian) are often considered 'healthy' and have been associated with broad health benefits, including decreased risk of obesity and ill health (cardiovascular disease, blood glucose and type II diabetes). However, the association between plant-based diets and mood disorders such as depression remains largely equivocal. This cross-sectional study of 219 adults aged 18-44 (M=31.22, SD=7.40) explored the associations between an estimate of overall plant-based diet quality and depression in vegans (n=165) and vegetarians (n=54). Overall plant-based diet quality was associated with depressive symptoms in vegans and vegetarians F(1, 215)=13.71, p<0.001 accounting for 6% of the variation in depressive symptoms. For those without depression, higher diet quality was protective against depressive symptoms F(1, 125)=6.49, p=0.012. Conversely, for those with depression no association with diet quality was found F(1, 89)=0.01, p=0.963. These findings suggest that a high-quality plant-based diet may be protective against depressive symptoms in vegans and vegetarians. In line with emerging research between food and mental health, higher-quality dietary patterns are associated with a reduced risk of depressive symptoms. Given the rapidly increasing rate of vegan and vegetarian food products within Australia, understanding the potential mechanisms of effects through which a plant-based diet may influence depressive symptoms is required.

Meat and mental health: A meta-analysis of meat consumption, depression, and anxiety

In this meta-analysis, we examined the quantitative relation between meat consumption or avoidance, depression, and anxiety. In June 2020, we searched five online databases for primary studies examining differences in depression and anxiety between meat abstainers and meat consumers that offered a clear (dichotomous) distinction between these groups. Twenty studies met the selection criteria representing 171,802 participants with 157,778 meat consumers and 13,259 meat abstainers. We calculated the magnitude of the effect between meat consumers and meat abstainers with bias correction (Hedges's g effect size) where higher and positive scores reflect better outcomes for meat consumers. Meat consumption was associated with lower depression (Hedges's g = 0.216, 95% CI [0.14 to 0.30], p < .001) and lower anxiety (g = 0.17, 95% CI [0.03 to 0.31], p = .02) compared to meat abstention. Compared to vegans, meat consumers experienced both lower depression (g = 0.26, 95% CI [0.01 to 0.51], p = .041) and anxiety (g = 0.15, 95% CI [-0.40 to 0.69], p = .598). Sex did not modify these relations. Study quality explained 58% and 76% of between-studies heterogeneity in depression and anxiety, respectively. The analysis also showed that the more rigorous the study, the more positive and consistent the relation between meat consumption and better mental health. The current body of evidence precludes causal and temporal inferences.

How vegans, vegetarians and carnists differ in personality traits and attitudes towards animals

BACKGROUND

Food decisions and dietary preferences are affected by a complex set of different cultural or regional factors, but personality traits seem to play an important role too. Previous research suggested that the food preferences related to veganism, vegetarianism, or carnism can be predicted by the Big Five model of personality and reflected in the attitudes towards animals.

PARTICIPANTS AND PROCEDURE

The present study examined personality traits and attitudes towards animals of 190 (M = 24.90, SD = 7.18) Slovak participants, of whom 57 were vegans, 56 vegetarians, and 77 carnists. To measure Big Five personality traits, the Big Five Inventory-2 (BFI-2) was used. Attitudes towards animals were measured by the short 10-item version of the Animal Attitude Scale (AAS-10).

RESULTS

Vegans and vegetarians scored significantly higher than carnists in open-mindedness and attitude towards animals; there was no difference between scores of vegans and vegetarians. No relationship between the diet groups and demographic variables (gender, education, and age) was identified. From personality traits and sociodemo-graphic variables, only open-mindedness was a significant predictor of attitudes towards animals.

CONCLUSIONS

Vegans and vegetarians differ from carnists primarily in one trait: open-mindedness. Vegans and vegetarians also differ from carnists by holding more positive attitudes towards animals.

To meat, or not to meat: A longitudinal investigation of transitioning to and from plant-based diets

Concerns over potential negative effects of excessive meat consumption on both the environment and personal health, coupled with long-standing debates over animal rights, have motivated research on the prevalence and predictors of plant-based versus meat-based diets. Yet few studies have examined longitudinal trends in dietary behaviours using large national samples. We address this gap by examining the prevalence, predictors, and annual change in the self-reported dietary behaviour of a large national probability sample of New Zealand adults (categorised as omnivore, vegetarian, or vegan; Ns = 12,259-50,964). Consistent with our pre-registered hypotheses, omnivore was the most prevalent dietary category (94.1%). Moreover, higher levels of conservative ideologies (i.e., political conservatism, Right-Wing Authoritarianism, and Social Dominance Orientation), lower subjective health, lower environmental efficacy, and lower disgust sensitivity predicted having an omnivore (vs. vegetarian or vegan) diet. Longitudinal analyses further revealed that the probability of shifting from an omnivore diet to a vegetarian or vegan diet over a one-year period was low, and that veganism was the least stable dietary category. Both gender (men) and political conservatism predicted lower probabilities of transitioning from meat to no-meat diets over time.

Fruit and Vegetable Dietary Patterns and Mental Health in Women: A Systematic Review

CONTEXT

Mental health may be influenced by some dietary patterns. Among common elements of beneficial patterns is high fruit and vegetable intake. However, no systematic review has been conducted to date, to our knowledge, that has assessed the influence of fruit and vegetable dietary patterns on a broad spectrum of mental health.

OBJECTIVE

We conducted a systematic review, using the PRISMA guidelines, of the observational studies analyzing the association between the dietary pattern of fruit and vegetables and the broad aspects of mental health in adult women.

DATA SOURCES

The databases PubMed and Web of Science were searched, and additional manual search for observational peer-reviewed studies was conducted for studies published until June 2019.

DATA EXTRACTION

A total of 5911 studies were extracted and verified based on title and abstract for the inclusion criteria. All procedures were conducted independently by 2 researchers. The final number of included studies was 30. The review was structured around the type of observed outcome.

DATA ANALYSIS

The included studies had defined habitual intake associated with dietary patterns with the intake of specific fruit and/or vegetables, and/or fruit or vegetable products (eg, juices), as well as any aspect of the broad spectrum of general mental health. The Newcastle-Ottawa Scale was used to assess bias. The observed association was not stated in all the included studies; some of them revealed a reverse relationship, but only for the vegetarian/vegan diet. A vegetarian diet may be characterized by high consumption of fruits and vegetables, but it sometimes may not be properly balanced, due to excluded products. This may be the reason of observed situation.

CONCLUSIONS

A general positive influence was observed for the dietary patterns characterized by high consumption of fruit and vegetables and of fruit or vegetable products by women.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42019138148.

Depression and Vegetarians: Association between Dietary Vitamin B6, B12 and Folate Intake and Global and Subcortical Brain Volumes

Deficiency of vitamin B6 and vitamin B12, mostly in vegetarians, is found to be associated with depression and adverse neurological function. We investigated whether vitamin B6, B12, and folate have an effect on brain structure, especially among depressed people who follow a specific diet. The study sample comprised 9426 participants from the UK Biobank cohort with a mean age of 62.4 years. A generalized linear model controlling for age, sex, body mass index, ethnicity, town send deprivation index, educational qualification, smoking, and alcohol intake was used to test the association between study groups and structural brain volumes. Depression was more prevalent, and intake of vitamin B6 and B12 was lower among vegetarians, while non-vegetarians had a lower intake of folate. Overall, no significant association was observed between vitamin B6, B12, and folate intakes and both global and subcortical brain volumes among participants with depression. However, vitamin B12 intake was positively associated with right pallidum among non-depressed participants, and a significant interaction between vitamin B12 intake and depression status on the right pallidum was observed. Also, a significant interaction between folate intake and depression status on grey matter (GM) volume and left thalamus was observed. Upon diet stratification, folate intake is associated with total brain volume and GM volume among vegetarians with depression. Furthermore, no significant associations were observed for subcortical regions. Our findings suggest that dietary intake of vitamin B6 and B12 might have an effect on brain structure. Vegetarians, particularly those who suffer from depression may benefit from supplementing their diets with vitamins B6, B12, and folate to ensure brain health. Further studies, especially with a larger sample size and longitudinal design, are needed to confirm these findings.

Diet, Physical Activity, and Disinhibition in Middle-Aged and Older Adults: A UK Biobank Study

Disinhibition is a prominent feature of multiple psychiatric disorders, and has been associated with poor long-term somatic outcomes. Modifiable lifestyle factors including diet and moderate-to-vigorous physical activity (MVPA) may be associated with disinhibition, but their contributions have not previously been quantified among middle-aged/older adults. Here, among N = 157,354 UK Biobank participants aged 40-69, we extracted a single disinhibition principal component and four dietary components (prudent diet, elimination of wheat/dairy/eggs, meat consumption, full-cream dairy consumption). In addition, latent profile analysis assigned participants to one of five empirical dietary groups: prudent-moderate, unhealthy, restricted, meat-avoiding, low-fat dairy. Disinhibition was regressed on the four dietary components, the dietary grouping variable, and self-reported MVPA. In men and women, disinhibition was negatively associated with prudent diet, and positively associated with wheat/dairy/eggs elimination. In men, disinhibition was also associated with consumption of meat and full-cream dairy products. Comparing groups, disinhibition was lower in the prudent-moderate diet (reference) group compared to all other groups. Absolute βs ranged from 0.02-0.13, indicating very weak effects. Disinhibition was not associated with MVPA. In conclusion, disinhibition is associated with multiple features of diet among middle-aged/older adults. Our findings foster specific hypotheses (e.g., early malnutrition, elevated immune-response) to be tested in alternative study designs.

Vegetarian diet is inversely associated with prevalence of depression in middle-older aged South Asians in the United States

Objective: To investigate associations between a vegetarian diet and depression among South Asians in the United States.Design: Data from 892 South Asians (age range 40-83 y, 47% women) enrolled in the Mediators of Atherosclerosis in South Asians Living in America (MASALA) study were included. A vegetarian diet was defined as no intake of meat, poultry or fish in the previous year as reported on a validated food frequency questionnaire. Depressive symptomology was assessed using the Center for Epidemiologic Studies-Depression Scale (CES-D) and depression was classified as CES-D score ≥16. Multivariable logistic regression was used and covariates included age, sex, study site, education, smoking, body mass index, acculturation, intentional exercise, alcohol and energy intake, and antidepressant medication use.Results: Our study demonstrated 43% lower odds of depression among vegetarians (p = 0.023).Conclusions: Vegetarian diet was found to be inversely associated with the prevalence of depression. Longitudinal examinations confirming these findings are needed.

Adherence to the vegetarian diet may increase the risk of depression: a systematic review and meta-analysis of observational studies

CONTEXT

Several epidemiological studies have investigated the association between a vegetarian diet and risk of depression, but because of inconsistency between studies, the exact association remains unclear.

OBJECTIVE

In this systematic review and meta-analysis, the relationship between vegetarian diets and risk of depression in observational studies was evaluated.

DATA SOURCES

The Medline, Embase, Scopus, ISI Web of Science, and Cochrane Library databases were searched from inception through September 1, 2020.

STUDY SELECTION

Observational studies were included that examined mean levels of depression and risk for depression in vegetarians compared with nonvegetarians.

DATA EXTRACTION

Pooled effect sizes were estimated using the random-effects model and were reported as standardized mean differences or odds ratios (ORs) with their corresponding 95%CIs. Heterogeneity was tested using the I2 statistic.

RESULTS

Combining 9 effect sizes in this meta-analysis illustrated that adherence to a vegetarian diet was associated with a 53% greater risk of depression compared with that of omnivores (95%CI, 1.14-2.07; I2 = 69.1%). Subgroup analysis of depression risk suggested that results depended on the type of vegetarian diet and country where the study was conducted. For studies that assessed a semivegetarian diet (OR, 1.86; 95%CI, 1.42-2.44; I2 = 35.7%) and those conducted in Europe and the United States (OR, 1.45; 95%CI, 1.06-1.98; I2 = 73.2%), there was a positive association between a vegetarian diet and depression, but in lacto-ovo vegetarians and Asian countries, a null association was found. Comparing mean depression scores showed no evidence of difference between vegetarians and nonvegetarians (n = 16; standardized mean difference, 0.10; 95%CI, -0.01 to 0.21; I2 = 79.1%).

CONCLUSION

Vegetarian diet significantly increased depression risk; however, the findings were not robust, and more studies are required to investigate the vegetarian diet and depression association.

Development and validation of the motivations to Eat Meat Inventory

Previous research suggests that there are four primary motives to eat meat: that it is natural, normal, necessary, or nice. However, these motives have not yet been distinguished empirically; the lack of a measurement tool that can distinguish these motives has contributed to a literature that focuses primarily on meat-eating motivation or justification in general, as opposed to differences between these motives. We developed a 19-item measure, the Motivations to Eat Meat Inventory (MEMI), that fit a four-factor model in three samples (total N = 2175), including one with a large number of vegetarians. Using this instrument, we generated psychological profiles associated with each motive, and showed that the structure and correlates of meat-eating motives is highly similar for omnivores and vegetarians. This research provides a valuable tool for studying variation in psychological motives for eating meat among both meat-eaters and vegetarians and provides an initial framework for understanding the underpinnings of these different motivations.

Vegetarianism and veganism compared with mental health and cognitive outcomes: a systematic review and meta-analysis

CONTEXT

Vegetarian and vegan diets are increasing in popularity. Although they provide beneficial health effects, they may also lead to nutritional deficiencies. Cognitive impairment and mental health disorders have a high economic burden.

OBJECTIVE

A meta-analysis was conducted to examine the relationship between vegan or vegetarian diets and cognitive and mental health.

DATA SOURCES

PubMed, Scopus, ScienceDirect, and Proquest databases were examined from inception to July 2018.

STUDY SELECTION

Original observational or interventional human studies of vegan/vegetarian diets were selected independently by 2 authors.

DATA EXTRACTION

Raw means and standard deviations were used as continuous outcomes, while numbers of events were used as categorical outcomes.

RESULTS

Of 1249 publications identified, 13 were included, with 17 809 individuals in total. No significant association was found between diet and the continuous depression score, stress, well-being, or cognitive impairment. Vegans/vegetarians were at increased risk for depression (odds ratio = 2.142; 95%CI, 1.105-4.148) and had lower anxiety scores (mean difference = -0.847; 95%CI, -1.677 to -0.018). Heterogeneity was large, and thus subgroup analyses showed numerous differences.

CONCLUSIONS

Vegan or vegetarian diets were related to a higher risk of depression and lower anxiety scores, but no differences for other outcomes were found. Subgroup analyses of anxiety showed a higher risk of anxiety, mainly in participants under 26 years of age and in studies with a higher quality. More studies with better overall quality are needed to make clear positive or negative associations.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42018097204.

Who gives a veg? Relations between personality and Vegetarianism/Veganism

With rates of vegetarianism and veganism (i.e., veg*nism) rising around the world, a growing body of research has begun to explore psychological characteristics that distinguish vegetarians and vegans from omnivores. However, relatively few studies have examined how veg*nism is related to differences in basic personality traits such as the "Big Five", with those that have tending to yield conflicting results. Moreover, none of these studies have examined personality at the lower levels of the personality trait hierarchy (i.e., aspects and facets of the Big Five). Thus, we sought to clarify how personality traits are related to veg*nism. In Study 1, comprising two samples (S1a: N = 797, S1b: N = 1534), participants were categorised as Veg*n vs Restricted-omnivore vs Omnivore, and completed personality questionnaires at the domain and aspect levels of the Big Five. In Study 2, participants (N = 562) completed both categorical and continuous measures of veg*nism, along with personality questionnaires at the domain, aspect, and facet levels. Across both studies, we found that people who scored higher on traits within the openness/intellect and agreeableness domains most consistently reported higher levels of veg*nism. Patterns in the data also suggested that the relation between personality and veg*nism might depend on the way veg*nism is measured. Theoretical and practical implications of these findings are discussed.

Orthorexic tendencies moderate the relationship between semi-vegetarianism and depressive symptoms

PURPOSE

Vegetarianism and semi-vegetarianism (i.e., overly vegetarian diet with rare consumption of meat) have been repeatedly linked with depression. As the nature of this association is unclear, we explored whether orthorexic (i.e., pathologically healthful eating) tendencies and ecological/ethical motives to follow a vegetarian diet may moderate the relationship between (semi-)vegetarian diets and depressive symptoms.

METHODS

Five-hundred eleven adults (63.4% females; 71.2% omnivores, 19.2% semi-vegetarians, 9.6% vegetarians) completed the Patient Health Questionnaire (PHQ-9) questionnaire-measuring depressive symptoms-and the Düsseldorf Orthorexia Scale (DOS)-measuring orthorexic tendencies. Based on respective questions, participants were categorized as omnivores, semi-vegetarians, and vegetarians (including vegans) and were asked to indicate whether they chose their diet based on ecological/ethical motives. Moderation analyses were carried out with PROCESS.

RESULTS

Adjusted for age, sex, and body mass index, there was a statistically significant interaction effect between diet (omnivore vs. semi-vegetarianism vs. vegetarianism) and DOS scores when predicting PHQ depression scores. At low or medium DOS scores, diets did not differ in PHQ depression scores (all ps > 0.05). At high DOS scores, however, semi-vegetarians had higher PHQ depression scores than both omnivores (p = 0.002) and vegetarians (p < 0.001). The interaction between diet and ecological/ethical eating motives when predicting PHQ depression scores was not statistically significant (p = 0.41).

CONCLUSION

Semi-vegetarians with strong orthorexic tendencies show more depressive symptoms than omnivores and vegetarians. The complex nature of the relationship between vegetarianism and depression requires further investigation.

LEVEL OF EVIDENCE

III, case-control analytic studies.

The Association Between Personality Traits and Dietary Choices: A Systematic Review

Increasing evidence shows how diet may play a role in improving health including mental health. Of note, personality may influence the type of diet and consequently the prognosis of medical and psychiatric conditions. The purpose of the present systematic review is to summarize the available data regarding the influence of personality on dietary habits affecting health outcomes. A search in the main databases was conducted matching the terms "personality," "personality traits" with "food choices," "food preferences," "diet," and "dietary habits." A total of 1856 articles were screened, and 24 articles were finally included. Exclusion criteria consisted of studies on animals or children, studies about eating disorders, types of diet not clearly associated with health outcomes, and studies for marketing reasons. Several studies showed that personality traits can influence both dietary choices and the type of diet, including the preference for healthy or unhealthy food. Unfavorable personality traits such as neuroticism and alexithymia (the inability to identify and describe emotions) were associated with unhealthy diet habits such as low consumption of fruit and vegetables, and the increased consumption of sugar and saturated fats. Personality seems to play a role in food selection and in the propensity to change diet. The interpretation of these results should be weighted by the different cultural contexts in which the studies were conducted and the extreme heterogeneity of tools used to assess personality and food preferences. Future research should clarify how personality can affect diet in specific populations such as patients with severe psychiatric disorders.

Vegetarian and omnivorous diets: A cross-sectional study of motivation, eating disorders, and body shape perception

Vegetarianism, which is increasingly widespread in Western societies, is underpinned by various motivations (ethical, environmental, health concerns …) and the question of its association with eating disorders continues to divide the literature. This cross-sectional study aimed to explore and compare eating motives/attitudes and bodily preoccupations of vegetarian and omnivorous participants from the general population. Forty-nine vegetarians and 52 omnivores, aged between 18 and 70 years, completed a battery of questionnaires including sociodemographic characteristics, Body Mass Indexes (BMI - current, ideal, lifetime lowest, and lifetime highest), the Food Choice Questionnaire (FCQ), the Eating Attitudes Test-26 (EAT-26), and the Body Shape Questionnaire (BSQ). Compared to omnivores, vegetarians reported lower current (p = .017), ideal (p = .009), and lifetime lowest (p = .005) BMIs, more motivations related to health (p = .001) and natural content (p < .0001), but less weight control motivations (p = .015). While no differences were observed in EAT-26 scores, vegetarians had lower BSQ total scores (p = .043), and lower scores on the Body Dissatisfaction related to Lower body parts (p = .025) and Unsuited Cognitions and Behaviors (p = .015) subscales compared to omnivores. Separate gender comparisons revealed that these differences existed only among women. Hierarchical regressions revealed that the natural content motivation was the strongest positive statistical predictor of the vegetarian group (Expβ = 1.18, p = .002), while the weight control motivation was a negative statistical predictor (Expβ = .710, p = .023). Results demonstrated that vegetarians expressed motivation for a healthy and natural diet, and were less concerned about controlling their weight than the omnivores. Vegetarian women had lower BMIs but expressed fewer psychological concerns associated with eating disorders than omnivorous women. Vegetarian diets appeared to be associated with health benefits and less body and weight concerns, particularly among women in the general population.

Níveis de Concordância com Regras Descritivas sobre Comportamentos Alimentares entre Veg(etari)anos

Resumo O vegetarianismo é uma prática que exclui carnes e pode evitar outros produtos de origem animal. Esta última modalidade está muito associada ao veganismo, uma filosofia que defende a libertação animal. Aderir a tais condições implica no seguimento de algumas normas que norteiam comportamentos alimentares e interações sociais. Partindo desse pressuposto, objetivou-se avaliar o nível de concordância, entre vegetarianos e veganos, quanto a regras que descrevem comportamentos alimentares. A pesquisa contou com 398 participantes, sendo 198 não estritos e 200 estritos, que responderam a um questionário on-line autoaplicável. Os dados, analisados via teste t, apontaram maiores níveis de concordância com comportamentos mais restritos entre vegetarianos estritos e veganos os quais também relataram maior embasamento em valores. Este estudo, que trouxe uma ótica de análise para os comportamentos alimentares em termos de localização de reforços, pode contribuir com novas práticas em saúde direcionadas às pessoas vegetarianas e veganas.

Less Animal-Based Food, Better Weight Status: Associations of the Restriction of Animal-Based Product Intake with Body-Mass-Index, Depressive Symptoms and Personality in the General Population

Restricting animal-based products from diet may exert beneficial effects on weight status; however, less is known about such a diet and emotional health. Moreover, personality traits, for example high neuroticism, may contribute to restrictive eating habits and potentially confound diet-health associations. We aim to systematically assess if restrictive dietary intake of animal-based products relates to lower weight and higher depressive symptoms, and if differences in personality traits play a significant role. Cross-sectional data from the baseline LIFE-Adult study were collected from 2011–2014 in Leipzig, Germany (n = 8943). Main outcomes of interest were dietary frequency of animal-derived products in the last year measured using a Food Frequency Questionnaire (FFQ), body-mass-index (BMI) (kg/m²), and the Center of Epidemiological Studies Depression Scale (CES-D). Personality traits were assessed in a subsample of n = 7906 using the Five Factor Inventory (NEO-FFI). Higher restriction of animal-based product intake was associated with a lower BMI, but not with depression scores. Personality, i.e., lower extraversion, was related to higher frequency of animal product intake. Moreover, personality traits were significantly associated with depressive symptoms, i.e., higher neuroticism, lower extraversion, lower agreeableness, lower conscientiousness, and with higher BMI. These findings encourage future longitudinal studies to test the efficacy of restricting animal-based products as a preventive and therapeutic strategy for overweight and obesity.

A Comprehensive Review of the Benefits of and the Barriers to the Switch to a Plant-Based Diet

In recent decades, the food industry has been faced with new challenges, and it has had to develop new types of diets and produce new types of foods that can slow down the spread of chronic diseases. The aim of our research was to identify the characteristics of plant-based nutrition, based on international and Hungarian literature. The comprehensive analysis was performed based on the theoretical model called Theory of Planned Behavior, in the course of which the perceived and objective benefits of and barriers to the conversion to a plant-based diet were examined. According to our results, the main benefits of plant-based nutrition are its many factors associated with a reduction in risk of developing numerous chronic diseases. This is followed by benefits of well-being and satisfaction, followed by ethical and environmental benefits. The most commonly reported inhibitory factor of a vegetarian diet is the enjoyment of eating meat and the difficulty in giving up meat consumption. This is followed by health considerations, e.g., lack of various ingredients in foods. Convenience and taste factors are also important disincentives, as well as the irrelevant nature of some plant-based nutrition information sources. Besides, social barriers, negative discrimination, and negative effect on mental health associated with them can also be a hindrance, as can financial barriers. The classification developed during our analysis can serve as a relevant guideline for decision-makers, and also as a basis for further primary qualitative and quantitative research.

Prevalence and psychopathology of vegetarians and vegans - Results from a representative survey in Germany

The aim of the study was to investigate the prevalence of, and attitudes toward, vegetarianism and veganism. We also assessed the association between vegetarianism/veganism and eating disorder, depressive, and somatic symptoms. A cross-sectional questionnaire survey in adults in Germany that was representative in terms of age, gender, and educational level was carried out. Data from 2449 adults (53.5% females) were included. Mean age was 49.6 (SD 17.1) years. A total of 5.4% of participants reported following a vegetarian or vegan diet. While the majority of participants agreed that vegetarian diets are healthy and harmless (56.1%), only 34.8% believed this to be true of vegan diets. The majority of participants also believed that a vegetarian (58.7%) or vegan (74.7%) diet can lead to nutritional deficiency. Female gender, younger age, higher education, lower body mass index (BMI), and higher depressive and eating disorder symptoms were found to be associated with vegetarianism/veganism. We did not find increased physical complaints in the group of vegetarians/vegans. Our results point toward a moderate prevalence of vegetarianism/veganism among the general population. Our findings suggest that health care professionals should keep eating disorder pathology, affective status in mind when dealing with individuals who choose a vegetarian/vegan dietary pattern.

Meat and mental health: a systematic review of meat abstention and depression, anxiety, and related phenomena

Objective: To examine the relation between the consumption or avoidance of meat and psychological health and well-being.Methods: A systematic search of online databases (PubMed, PsycINFO, CINAHL Plus, Medline, and Cochrane Library) was conducted for primary research examining psychological health in meat-consumers and meat-abstainers. Inclusion criteria were the provision of a clear distinction between meat-consumers and meat-abstainers, and data on factors related to psychological health. Studies examining meat consumption as a continuous or multi-level variable were excluded. Summary data were compiled, and qualitative analyses of methodologic rigor were conducted. The main outcome was the disparity in the prevalence of depression, anxiety, and related conditions in meat-consumers versus meat-abstainers. Secondary outcomes included mood and self-harm behaviors.Results: Eighteen studies met the inclusion/exclusion criteria; representing 160,257 participants (85,843 females and 73,232 males) with 149,559 meat-consumers and 8584 meat-abstainers (11 to 96 years) from multiple geographic regions. Analysis of methodologic rigor revealed that the studies ranged from low to severe risk of bias with high to very low confidence in results. Eleven of the 18 studies demonstrated that meat-abstention was associated with poorer psychological health, four studies were equivocal, and three showed that meat-abstainers had better outcomes. The most rigorous studies demonstrated that the prevalence or risk of depression and/or anxiety were significantly greater in participants who avoided meat consumption.Conclusion: Studies examining the relation between the consumption or avoidance of meat and psychological health varied substantially in methodologic rigor, validity of interpretation, and confidence in results. The majority of studies, and especially the higher quality studies, showed that those who avoided meat consumption had significantly higher rates or risk of depression, anxiety, and/or self-harm behaviors. There was mixed evidence for temporal relations, but study designs and a lack of rigor precluded inferences of causal relations. Our study does not support meat avoidance as a strategy to benefit psychological health.