Vegetarian Nutrition

VN: Types and Diversity of Vegetarian Diets (2009)

Citation:

Bas, Murat; Karabudak, Efsun; Kiziltan, Gül. Vegetarianism and eating disorders: Association between eating attitudes and other psychological factors among Turkish adolescents. Appetite, Jun2005, Vol. 44 Issue 3, pp. 309-315.

PubMed ID: 15927731
 
Study Design:
Cross-Sectional Study
Class:
D - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

To investigate the relationship between vegetarianism and eating attitudes, self-esteem, social trait anxiety and social physique anxiety among Turkish adolescents.

Inclusion Criteria:

Male and female university students in Ankara, Turkey.

Exclusion Criteria:

No specific exclusion criteria were indicated.

Description of Study Protocol:

Recruitment

  • Six public and four private universities in Ankara, Turkey were selected using a multistage cluster sampling method
  • Study population came from these 10 schools but no specific information on recruitment was provided
  • Further recruitment protocol was not clearly specified.

Design

 Cross sectional study

Blinding used

 N/A

Intervention

  • One questionnaire and four survey instruments were administered to participants in face-to-face interviews between February and July 2004
  • All instruments were self-reported inventories. 

Statistical Analysis

  • Pearson Χ2 used to assess categorical data
  • Mann-Whitney U Test used to determine differences between vegetarian and non-vegetarian group mean values
  • Spearman correlation coefficient used to determine relationships among BMI, SPAS, STAI, self-esteem and eating attitudes scores
  • Results reported as mean ± standard deviation
  • Statistical significance P<0.05.
Data Collection Summary:

Timing of Measurements

  • Single visit face-to-face interview conducted between February and July 2004
    • Participants completed a questionnaire and four different surveys measuring eating attitudes and psychological factors
      • Vegetarianism identification questionnaire
      • EAT-26
      • Rosenberg self-esteem scale
      • SPAS
      • STAI.

Dependent Variables

  • Eating attitudes: Eating Attitudes Test (EAT-26)
    • Three sections designed to measure symptoms of anorexia nervosa
      • Dieting?degree of avoidance of fattening foods and preoccupation with being thinner
      • Bulimia and preoccupation with food
      • Oral control?degree of self-control around food and the perception of pressure from others to gain weight
    • Scoring
      • Total score range is 0 to 53
      • Score ≥20 indicated abnormal eating behavior
      • Score <20 indicated normal eating behavior
  • Self esteem: Rosenberg self-esteem scale
    • 10 items
    • Four-point Likert scale
  • Social physique anxiety: Social physique anxiety scale (SPAS)
    • Designed to determine the degree to which people become anxious to the real or perceived evaluation of their physique by others
    • 12 items
    • Five-point Likert scale
  • Subjective level of anxiety: State-Trait Anxiety Inventory (STAI). Designed to measure the subjective level of anxiety in special stations and in general.

Independent Variables

  • Self-identified vegetarianism vs. non-vegetarianism. Questionnaire (purportedly there were three sections but only two were described):
    1. Socio-demographic items including sex, age, weight, height and BMI
    2. Questions concerning participants' past and present vegetarianism experiences
      • Initial question meant to identify vegetarians vs. non-vegetarians; "Are you a vegetarian?"
      • If individual replied "yes", further questions were asked about duration and reasons for their decision.

Control Variables

Sex

Description of Actual Data Sample:

Initial N

  • N=1,205 (608 males; 597 females)
  • There is a discrepancy in the reporting of N; numbers above are the numbers reported in the tables, numbers are reversed in the text of the article.

Attrition (final N)

N=1,205

Age

  • Mean 21.5±1.9 years
  • Range 17 to 21 years
  • May be a discrepancy in reporting of age range for subject population.

Ethnicity

  • Title of article specifies Turkish adolescents
  • Not clearly specified in Methods section.

Other relevant demographics

  • Participants equally divided by gender (49.6% males, 50.4% females reported)
    • These percentages agree with numbers reported in text, not those in the tables
  • Most participants attended public university (70.71%) rather than private university (29.29%)
  • Participant self-reports identified vegetarians (Males: N=8; Females: N=23) and non-vegetarians (Males: N=600; Females N=574).

Anthropometrics 

  • No significant differences in height, weight or age between vegetarians and non-vegetarians
  • Mean value of BMI of female vegetarians (19.78±1.49) significantly different (P<0.05) from BMI (20.78±2.46) of female non-vegetarians
  • BMI characteristics of participants
    • All vegetarians were underweight or normal weight
    • No vegetarians were overweight or obese

BMI Categories

BMI (kg/m2) Male Veg Male Non-Veg Female Veg Female Non-Veg
Underweight (<18.5) 7 24 3 103
Normal (18.5-24.9) 1 469 20 427
Overweight (25-29.9) -- 94 -- 42
Obese (30) -- 13 -- 2

 

 

 

 

 

Location

Ankara, Turkey

Summary of Results:

Major findings

  • Disturbed eating behaviors (EAT-26 score ≥20) were found in 14 (two males and 12 females) out of 31 vegetarians
  • There was a significant difference between vegetarians and non-vegetarians on the EAT-26 total score for both males (Χ2=6.432, P=0.040) and females (X2=29.366, P=0.000)
  • Male vegetarians demonstrated significantly higher scores than male non-vegetarians on
    • EAT-26 total score
    • Dieting subcategory
    • Oral control subcategory
  • Female vegetarians demonstrated significantly higher scores than female non-vegetarians on
    • EAT-26 total score
    • Dieting subcategory
    • Oral control subcategory
    • STAI.

 Table 1: Outcomes for Males

Scores for males Vegetarians Non-vegetarians Statistical Significance of Group Difference

EAT-26 total score

17.25±11.18 9.38±6.60 0.019*
 F1: Dieting

6.5±7.65

2.55±3.87

0.016*

 F2: Bulimia/preoccupation

4.63±2.67

3.63±1.85

0.200
 F3: Oral control 6.13±4.67 3.20±3.19 0.038*
 RSE 23.5±3.38 21.33±4.59 0.121
 SPAS 23.75±11.31 27.07±7.54 0.132
 STAI 46.5±5.90 46.64±5.33 0.631

 * denotes P<0.05, significant difference

Table 2: Outcomes for Females

Scores for females Vegetarians Non-vegetarians

Statistical Significance of Group Difference

EAT-26 total score 22.04±13.62 11.38±8.28 0.000*
 F1: Dieting 10.35±9.58 4.41±5.30 0.000*
 F2: Bulimia/preoccupation  3.91±1.90 3.64±1.67 0.257
 F3: Oral control 7.78±5.13 3.33±3.51 0.000*
 RSE 21.26±6.98 21.46±4.34 0.614
 SPAS 30.70±8.58 29.40±7.72 0.299
 STAI 51.39±7.28 47.29±5.13 0.004*

 * denotes P<0.05, significant difference

Other Findings

  • Vegetarians had statistically significant (P<0.05) higher dieting scores than non-vegetarians related to:
    • Perceptions of dieting
    • The degree of avoidance of fattening foods
    • The preoccupation with being thinner
  • Nearly all male vegetarians were underweight (seven of eight)
  • No significant difference in self-esteem scores found between groups
  • A positive correlation was noted between social physique anxiety and dieting scores (r=0.363, P<0.05)
  • A negative correlation was found between self-esteem and social physique anxiety scores (r=0.623, P<0.05).

 

Author Conclusion:

Abnormal eating attitudes, low self-esteem, high social physique anxiety and high trait anxiety was associated with this sample of Turkish vegetarian adolescents.

Funding Source:
Other: Not reported
Reviewer Comments:

There were several discrepancies noted in the article

  • N's were different between the text and tables
  • Definition of adolescent appeared to include an older age range (mean age of 21.5 years; range of 17 to 21 years) than the "American" definition 
  • Grammar errors noted in translation from Turkish to English
  • This study may not have high generalizability
  • BMI distribution of this sample is quite different from typical distribution of American college-age students.
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) Yes
  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) Yes
  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) Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
 
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? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  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? Yes
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? Yes
  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? 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.) 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? 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? Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  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? ???
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? ???
  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? Yes
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? Yes
  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? Yes
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? Yes
  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? 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? 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? 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? Yes
  8.6. Was clinical significance as well as statistical significance reported? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? No
  8.7. If negative findings, was a power calculation reported to address type 2 error? No
  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? No
  10.1. Were sources of funding and investigators' affiliations described? No
  10.2. Was the study free from apparent conflict of interest? Yes
  10.2. Was the study free from apparent conflict of interest? Yes