VN: Types and Diversity of Vegetarian Diets (2009)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:

To accumulate and interpret a body of verbatim interviews to understand the beliefs and choices of vegetarians.

Inclusion Criteria:
  • Self-defined as vegetarian
  • Older than age 16 years
  • Caucasian.
Exclusion Criteria:

Non-white individuals.

Description of Study Protocol:

Recruitment

Snowball technique (in which initial contacts are asked for contacts within their social networks).

Design

In-person, unstructured interviews that covered an inventory of topics. Interviews were taped and transcribed. Information from transcripts was organized according to themes.

Intervention

None.

Statistical Analysis

Content (discursive) analysis.

Data Collection Summary:

Timing of Interviews

October 1987 to February 1989.

Aspects of Vegetarian Individuals Explored

  • Respondent characteristics
  • Types of vegetarianism
  • Process of "conversion" to vegetarianism
  • Motivations
  • Beliefs about nutrition
  • Social relations
  • Challenges faced by vegetarians
Description of Actual Data Sample:

Initial N: 76 (39 female and 37 male)

Age: Adult

Ethnicity: White

Other relevant demographics: The majority of interviewees had attained a high level of education. The majority of interviewees did not have dependent children.

Anthropometrics: None reported

Location: United Kingdom.

Summary of Results:

Food intake pattern is only one aspect of a vegetarian dietary style. How and what a person eats is often an integral part of self-image and attitudes about the larger world, and this can be particularly true for vegetarians.

Scholars Alan Beardsworth and Teresa Keil use sociological and anthropological methods of analysis to understand how vegetarians make meaning of their diet and lifestyle.

Types of Vegetarianism

The authors identify a continuum of six general types of vegetarian diets, running from least to most restrictive.

  1. Meat consumers
  2. Fish consumers
  3. Egg consumers
  4. Dairy product consumers
  5. Those who refuse any animal products associated with animal slaughter (so, dairy products are allowed, but only certain sources)
  6. Those who consume vegetable-derived products only.

It may seem contradictory to include meat consumers in a list of vegetarians, but, say the authors, several of their respondents indicated that they weigh the importance of their preferred (meat-free) dietary habits against the importance of their relationships in a particular situation. In other words, if refusing meat will cause uncomfortable social situations, some vegetarians will eat meat out of deference to the other person. This kind of attitude is captured well in an excerpt from an interview with one respondent.

"Over the last few years I have...stopped eating meat altogether unless it is some sort of social function where it is going to be extremely embarrassing for the other person, i.e., on occasion being invited by somebody I don't know very well to their house and then finding they've prepared meat, and I would eat it."...[Interviewer: "Does that occur very often?"]..."Very rarely now. But on the odd occasion, yes...my principles aren't strong enough to make a social upset." (Female respondent)

So, for some vegetarians, their preferred food intake is weighed against social factors in the particular situation. But, simply because a person who chooses a meat-free lifestyle occasionally eats meat does not automatically exclude them from being a vegetarian.

The Process of Becoming Vegetarian

The authors were interested in discovering why individuals would become vegetarians in the first place. Because of this, they excluded people who had been raised in vegetarian households and non-white vegetarians (because, according to the authors, many non-whites come from backgrounds whose culture or religion dictate a vegetarian diet).

They identify two broad paths of "conversion" to vegetarianism:

  1. A gradual process of change over time as individuals begin to act on vague misgivings about meat consumption
  2. A sudden change of diet, often associated with an event that produced strong reactions of distress or disgust.

Both paths often involved a reconceptualization of meat as "flesh" in which the source of the meat food became more relevant to their dietary decisions. In fact, two respondents had taken to referring to meat as "corpses". Eating "beef" has very different emotional implications than eating "flesh" or a "corpse".

Other Factors Behind Conversion

Individuals may become vegetarians through a number of influences (that are not mutually exclusive). For instance,

  • Some become vegetarian in response to a particular event, like witnessing an animal being slaughtered
  • Some become vegetarians because of media influences (for instance, a documentary on the animal processing industry)
  • Others become vegetarian slowly through the influence of others (friends, spouses, other family members).

Motivations for Being Vegetarian

What motivates people to become vegetarians? What are the beliefs behind a vegetarian lifestyle?

The authors identify four main reasons why their interviewees became vegetarians. They note that these motivations are not exclusive. Most respondents offered more than one motivation, although they generally identified one motivation as paramount.

  1. Moral. Many of the vegetarians say that they follow a vegetarian lifestyle on moral grounds. That is, they believe that it is simply morally unjustifiable to kill and eat another living being. The way animals are treated by the food industry often played into this type of motivation.
  2. Health-related. Other individuals cited health concerns of meat (for example, additives, nutritional value, etc.) or the health benefits of a meat-free diet
  3. Gustatory. Some respondents simply do not like meat either because of taste or texture
  4. Ecological. Several individuals viewed their dietary habits as part of a larger concern for the environment. They told the authors that a vegetarian lifestyle left a smaller environmental footprint than eating animals (for instance, it takes less grain to feed a person than to feed the animals that humans would eat).

In addition to the fact that almost all of the vegetarians interviewed identified multiple reasons for being vegetarian, the authors noted that these beliefs were not static. Motives changed over time, and this sometimes prompted vegetarians to adopt a stricter form of vegetarianism.

Beliefs About Nutrition

The authors say that respondents differed widely in terms of their attitudes about food and patterns of nutrition beliefs. They identify three major themes.

  1. Anti-meat theme. Respondents often expressed opinions about meat as bad for you (e.g., additives, hormones), that it was immoral or that it was environmentally irresponsible
  2. Pro-meat theme. It was not unusual for interviewees to also express nostalgia for meat (e.g., the memory of bacon cooking when they were a kid), or admitted liking the taste of meat, but avoiding it for reasons other than taste
  3. Pro-vegetarian theme. Respondents also praised the virtues of vegetarianism. A topic that came up several times was the notion of increased diversity in the diet. Interviewees often felt that in dropping meat they were forced to add more variety to their diet (different kinds of food sources). Some also saw vegetarianism as a way of breaking free from conformity to the standard meat-and-potatoes diet rut.

As with other attitudes or motivations, these themes were not mutually exclusive. Respondents often expressed more than one.

Social Relations

The authors also found that vegetarian lifestyles affected relationships. Examples include:

  • Positive and supportive reactions from friends or families (for example, others in their close social circle following suit or preparing meals to fit with their diet convictions)
  • Negative reactions (from parents, co-workers, roommates, parents-in-law) because the vegetarian change in diet was seen as inconvenient, strange or taken as a critique of the other person's lifestyle. The authors report that Christmas was a particular source of tension because traditional Christmas foods include meat.
  • After adopting vegetarianism, people often sought out others like themselves and extended their social networks to include other vegetarians.

Dilemmas

Apart from potential conflicts in their relationships, vegetarians also face certain moral dilemmas. The authors found that vegetarians' attitudes about and use of non-food animal products could provoke tensions. For example, the question of whether to wear leather clothes troubled some of the respondents. If they opposed eating meat on moral or environmental grounds, then using animal-based products was not consistent with their commitments. In reaction to this, some respondents reported becoming more "strict": refusing to wear animal products and learning to carefully read labels. Others simply lived with the inconsistency, perhaps rationalizing their behavior. Those who adopted a vegetarian diet simply because they did not like meat did not experience any emotional tension.

The authors identify one unifying theme for those who adhere to a vegetarian diet: The deep-seated ambivalence associated with the very act of eating.

  • Although food is required for vigor and health, it may also introduce illness and disease
  • Although food may produce gustatory pleasure, it may also produce revulsion
  • Although food is required to continue life, it also entails the death of the organisms being consumed.

Bottom Line

Persons who adopt vegetarianism as adults vary widely in terms of:

  • Diet (foods eaten, how they are prepared)
  • Paths to becoming vegetarian
  • Motivations for becoming vegetarian
  • Beliefs about nutrition
  • Effects on relationships
  • Dilemmas and psychological tensions they face making their dietary practices and commitments consistent with their overall lifestyle.
Author Conclusion:

Vegetarians are a heterogenous group, varying in dietary habits, nutrition beliefs, motivations and level of commitment. Vegetarians are also complex in that beliefs and behaviors change over time—sometimes becoming more strict, sometimes less strict.

Ethical considerations often played a central role in the interviewees' nutrition choices and broader lifestyles. 

Funding Source:
Not-for-profit
Nuffield Foundation, UK
Other non-profit:
Reviewer Comments:

A well-executed anthropological-style study.

The purpose was to try to understand how vegetarians understand their dietary practices within their larger lives and social contexts. Although the study is subject to the usual limitations of qualitative research, it provides valuable insight into the people behind the diet.

One limitation is the very narrow sample of only adults and only white individuals. It is unclear to what extent the findings may be generalized to other populations.

Because the Nutrition Care Process requires the dietitian to be sensitive to patient/client beliefs and convictions, this study may provide a valuable tool for practice.

 

Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) N/A
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) N/A
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) N/A
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) N/A
 
Validity Questions
  1. Was the research question clearly stated? Yes
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
  1.3. Were the target population and setting specified? Yes
  2. Was the selection of study subjects/patients free from bias? No
2. Was the selection of study subjects/patients free from bias? No
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? Yes
  2.2. Were criteria applied equally to all study groups? N/A
  2.2. Were criteria applied equally to all study groups? N/A
  2.3. Were health, demographics, and other characteristics of subjects described? No
  2.3. Were health, demographics, and other characteristics of subjects described? No
  2.4. Were the subjects/patients a representative sample of the relevant population? No
  2.4. Were the subjects/patients a representative sample of the relevant population? No
  3. Were study groups comparable? N/A
3. Were study groups comparable? N/A
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) N/A
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) N/A
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? N/A
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? N/A
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) No
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) No
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? N/A
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? N/A
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
  4. Was method of handling withdrawals described? N/A
4. Was method of handling withdrawals described? N/A
  4.1. Were follow-up methods described and the same for all groups? N/A
  4.1. Were follow-up methods described and the same for all groups? N/A
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) N/A
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) N/A
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? N/A
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? N/A
  4.4. Were reasons for withdrawals similar across groups? N/A
  4.4. Were reasons for withdrawals similar across groups? N/A
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
  5. Was blinding used to prevent introduction of bias? N/A
5. Was blinding used to prevent introduction of bias? N/A
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? N/A
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? N/A
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) N/A
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) N/A
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
  6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? N/A
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? N/A
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? Yes
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? Yes
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? N/A
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? N/A
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? N/A
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? N/A
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? N/A
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? N/A
  6.6. Were extra or unplanned treatments described? N/A
  6.6. Were extra or unplanned treatments described? N/A
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? N/A
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? N/A
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
  7. Were outcomes clearly defined and the measurements valid and reliable? Yes
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? N/A
  7.1. Were primary and secondary endpoints described and relevant to the question? N/A
  7.2. Were nutrition measures appropriate to question and outcomes of concern? N/A
  7.2. Were nutrition measures appropriate to question and outcomes of concern? N/A
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? N/A
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? N/A
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? N/A
  7.5. Was the measurement of effect at an appropriate level of precision? N/A
  7.6. Were other factors accounted for (measured) that could affect outcomes? N/A
  7.6. Were other factors accounted for (measured) that could affect outcomes? N/A
  7.7. Were the measurements conducted consistently across groups? N/A
  7.7. Were the measurements conducted consistently across groups? N/A
  8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? N/A
  8.1. Were statistical analyses adequately described and the results reported appropriately? N/A
  8.2. Were correct statistical tests used and assumptions of test not violated? N/A
  8.2. Were correct statistical tests used and assumptions of test not violated? N/A
  8.3. Were statistics reported with levels of significance and/or confidence intervals? N/A
  8.3. Were statistics reported with levels of significance and/or confidence intervals? N/A
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? N/A
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? N/A
  8.6. Was clinical significance as well as statistical significance reported? N/A
  8.6. Was clinical significance as well as statistical significance reported? N/A
  8.7. If negative findings, was a power calculation reported to address type 2 error? N/A
  8.7. If negative findings, was a power calculation reported to address type 2 error? N/A
  9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
  10. Is bias due to study's funding or sponsorship unlikely? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes
  10.2. Was the study free from apparent conflict of interest? Yes