Vegetarian Nutrition

VN: Types and Diversity of Vegetarian Diets (2009)

Citation:

Santos ML, Booth DA. Influences on meat avoidance among British students. Appetite. 1996 Dec; 27(3): 197-205.

PubMed ID: 9015557
 
Study Design:
Cross-Sectional Study
Class:
D - Click here for explanation of classification scheme.
Quality Rating:
Negative NEGATIVE: See Quality Criteria Checklist below.
Research Purpose:

To identify the pattern of progressive meat avoidance by looking at the consumption patterns of different kinds of meat, and to identify the reasons behind avoiding meats.

Inclusion Criteria:
  • Undergraduates at the University of Birmingham who selected a vegetarian dish at a university dining hall
  • Females (for the interview section of the study).
Exclusion Criteria:

None reported.

Description of Study Protocol:

Recruitment

A meat-avoidance questionnaire was administered to undergraduates (18 to 23 years old; 68% in their first year) who chose a vegetarian dish in a Hall of Residence dining hall or restaurants at the University of Birmingham in October 1993.

Design

Initial survey with a follow-up interview with a subsample (all female) of the initial survey group.

Statistical Analysis

Frequencies and percentages, using a chi-square statistic to test for group differences. Significance set at P<0.05.

Data Collection Summary:

Timing of Measurements

October, 1993.

Dependent Variables

  • Pattern of meat consumption and avoidance:
    • Flesh eaters
    • Partial meat and fish avoiders
    • Eaters of fish only
    • Vegetarians (no flesh foods)
  • Reasons for choosing the particular vegetarian dish at the time of the survey.

Independent Variables

  • Reasons for choosing to avoid meats
  • Patterns of eating at home.

Control Variables

Sex.

Description of Actual Data Sample:
  • Initial N: Initial number of surveys handed out was not reported. 240 questionnaires were returned.
  • Attrition (final N): 158 surveys were usable (33 males and 125 females)
  • For the interview phase of the study: 41 (all female), 33 from the survey and eight volunteers
  • Age: 18 to 23 years
  • Location: United Kingdom.
Summary of Results:
  • The proportion of women who professed to make vegetarian choices at university was significantly greater than the proportion reporting vegetarianism at home (P<0·0005)
  • Men differed from the women in reporting vegetarian choices at university in fewer numbers than reported at home, overall (P<0·0005)
  • Persons who avoided red meat (P<0·0005) or white meat (P<0·0005) were more likely to avoid fish than people who ate these other meats (no difference among sexes).

Graduation from Carnivore to Vegetarian

  • Both men and women reported choices before university that lay close to a gradated scale from eating both “red” meats (beef and lamb) and “white” meats (chicken and turkey) through avoiding those “red” meats but still eating fowl to avoiding both these categories of meat (P<0.0005 for both sexes and overall). Some men who ate red meat avoided poultry (NS). The same pattern held for “graduating” away from pork to foul and then to vegetarianism for both men and women (P<0.0005 for both sexes).
  • In this study, pork appeared to function as an alternative to beef and lamb, and fish was not used as the “last meat” before graduating to vegetarianism.
  • In this sample, women appeared to eat more in accord with the gradation towards vegetarianism than men.
  • Fish was chosen by similar minorities among eaters and avoiders of beef and lamb and of poultry. This provides evidence that fish is not always the last flesh food consumed just before moving to full vegetarianism (consumption of fish is generally low among British young people).

Reasons for Vegetarianism and Dish Choice

Partial meat avoiders and vegetarians were asked to give reasons for their choices. The following table provides the percent who provided the different types of answers.

Reason

Partial Meat Avoiders

Vegetarian

First Choice

Other Choice

First Choice

Other Choice

Ethical

32

18

54

38

Dislike

11

25

15

46

Disgust

18

29

8

38

Health

14

32

0

0

Social influences

11

7

8

8

Other

14

21

15

8

  • Ethical principles and dislike of meat were mentioned first slightly more often by vegetarians than by partial meat avoiders (difference not significant)
  • Partial meat avoiders gave a wider range of reasons than vegetarians, though the difference was not statistically significant
  • When asked about the dish they had just chosen, sensory aspects were mentioned most often and it appears that food choice had more to do with what happened to be available
  • The change toward vegetarianism at the university may reflect more direct contact with food, where the students are exposed to body parts, blood, eyes, etc. Such experiences are likely to arouse feelings of repugnance at eating an animal that has been raised and killed to feed them.
  • Fully vegetarian students interviewed were concerned mainly with ethical issues widely discussed in the media, although “dislike” of meat was also given as a major reason for avoiding it
  • Partial meat avoiders may have offered a wider range of reasons because of a need to justify their equivocal position on the issues of meat-eating and vegetarianism.
Author Conclusion:

More women than men had avoided meat and other flesh foods, with the exception of fish. Consistently with the distinction between “red” and “white” meats, chicken and turkey were the least often avoided flesh foods among men and women. The only clear gradation from flesh-eating to vegetarianism was eating poultry and either beef and lamb or pork, eating only poultry and eating neither; fish was not on this scale, contrary to previous assumptions.

Reasons for avoiding meat were diverse, but always included at least two of the following: Ethics of raising and killing animals, concern for health, sensory factors, disgust and influence of friends.

Funding Source:
Government: PRAXIS XXI, JNICT, Portugal and Programmas CIENCIA 2
Reviewer Comments:

The study was small and unsystematic.

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? 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? No
  2.2. Were criteria applied equally to all study groups? No
  2.2. Were criteria applied equally to all study groups? No
  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? No
3. Were study groups comparable? No
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) No
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) No
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? No
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? No
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) Yes
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) Yes
  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? 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? No
  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.) No
  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.) No
  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? No
4. Was method of handling withdrawals described? No
  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%.) No
  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%.) No
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? No
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? No
  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? No
5. Was blinding used to prevent introduction of bias? No
  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.) No
  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.) No
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? No
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? No
  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? No
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? No
  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? No
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? No
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? No
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? No
  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? N/A
7. Were outcomes clearly defined and the measurements valid and reliable? N/A
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  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? No
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? No
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? No
  7.6. Were other factors accounted for (measured) that could affect outcomes? No
  7.7. Were the measurements conducted consistently across groups? Yes
  7.7. Were the measurements conducted consistently across groups? Yes
  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? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  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)? No
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? No
  8.6. Was clinical significance as well as statistical significance reported? No
  8.6. Was clinical significance as well as statistical significance reported? No
  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? No
9. Are conclusions supported by results with biases and limitations taken into consideration? No
  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? No
  9.2. Are biases and study limitations identified and discussed? No
  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