investigation sur les raisons individus à devenir vegan .pdf



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Titre: Investigation of lifestyle choices of individuals following a vegan diet for health and ethical reasons
Auteur: Cynthia Radnitz

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Appetite 90 (2015) 31–36

Contents lists available at ScienceDirect

Appetite
j o u r n a l h o m e p a g e : w w w. e l s e v i e r. c o m / l o c a t e / a p p e t

Research report

Investigation of lifestyle choices of individuals following a vegan diet
for health and ethical reasons ☆
Cynthia Radnitz a,*, Bonnie Beezhold b, Julie DiMatteo a
a
b

School of Psychology, Fairleigh Dickinson University, 1000 River Rd., Teaneck, NJ 07666, USA
Department of Nutrition, Benedictine University, 5200 College Drive, Lisle, IL 60532, USA

A R T I C L E

I N F O

Article history:
Received 30 December 2014
Accepted 19 February 2015
Available online 25 February 2015
Keywords:
Ethical vegan
Health vegan
Vegetarian
Health behaviors
Vegan
Nutrition

A B S T R A C T

The proportion of individuals choosing to follow a vegan diet has increased in recent years. The choice
is made for different reasons, primarily concern for animals (ethics) and health, which may impact both
specific food choices and other lifestyle behaviors linked to health outcomes. To determine the extent
to which the reason for following a vegan diet was associated with health behaviors, we conducted an
online survey recruiting an international sample of 246 individuals who reported adhering to a vegan
diet. We hypothesized that compared to those following the diet for ethical reasons, those doing so for
health reasons would consume foods with higher nutritional value and engage in other healthier lifestyle behaviors. Our hypotheses were partially supported in that those citing health reasons (n = 45) reported
eating more fruit (U = 3503.00, p = 0.02) and fewer sweets (U = 3347.00, p < 0.01) than did those citing
ethical reasons (n = 201). Individuals endorsing ethical reasons reported being on the diet longer (U = 3137.00,
p < 0.01), and more frequent consumption of soy (U = 2936.00, p < 0.01), foods rich in vitamin D (U = 3441.00,
p = 0.01), high-polyphenol beverages (U = 3124.50, p < 0.01), and vitamin supplements (vitamin D: χ2 = 4.65,
p = 0.04; vitamin B12: χ2 = 4.46, p = 0.03) than did those endorsing health reasons. As these factors may
affect outcome in studies investigating the impact of vegan diets on health, they should be taken into
account when studying persons following a vegan diet.
© 2015 Elsevier Ltd. All rights reserved.

Introduction
The proportion of Americans following a vegan diet has increased substantially in the past 15 years from approximately
300,000 to 500,000 people in 1997 to between 2.5 and 6 million
in 2012 (1–2% of the U.S. population; Newport, 2012; Stahler, 2012).
The number of vegans worldwide has yet to be established, although research indicates that this number is on the rise, especially
in more affluent countries (Key, Appleby, & Rosell, 2006). For
example, a recent survey in Israel reported that 5% of Israelis consumed a vegan diet (Aharoni, 2014). In a survey of 3618 individuals
in the United Kingdom, 2% self-identified as vegan (Department
for Environment, Food and Rural Affairs, 2007), while in another
survey of Australians, 1% reported following a vegan diet (The
Vegetarian/Vegan Society of Queensland Incorporated (VVSQ), 2013).
In Germany there are 900,000 vegans, approximately 1% of the population (VEBU, 2014). Surprisingly, India, which has a large number

☆ Acknowledgements: The authors would like to acknowledge the assistance of Carol
Burtnack, Maria DiNello, Michael Greenberg, Michelle Herrera, Cassandra Hoy, Tyler
Loranger, Bret Moyer, Amy Rinne, Melissa Sharp, and Jessica Dalrymple.
* Corresponding author.
E-mail address: radnitz@fdu.edu (C. Radnitz).

http://dx.doi.org/10.1016/j.appet.2015.02.026
0195-6663/© 2015 Elsevier Ltd. All rights reserved.

of vegetarians (31%; Yadav & Kumar, 2006) has a relatively small
number of vegans. Moreover, in early 2014, Google Trends reported the highest level of searches for the term ‘vegan’ (100 on
scale of 0–100; Google Trends, 2014).
One reason for this interest in a vegan diet is its reported health
benefits. There have been several studies documenting the nutritional and health status of vegans (Craig, 2009; Dwyer, 1988; Key
et al., 2006). In a cross-sectional study, vegans were found to have
an average body mass index (BMI) of 23.6 compared to nonvegans who had a mean BMI of 28.8 (Tonstad, Butler, Yan, & Fraser,
2009); a BMI of 22.5 to 25 is considered ideal (Mahan &
Escott-Stump, 1999). Similarly, vegans are found to have lower cholesterol (Bradbury et al., 2013) and blood pressure (Pettersen,
Anousheh, Fan, Jaceldo-Siegl, & Fraser, 2012), as well as reduced risk
of cardiovascular disease (Spencer, Appleby, Davey, & Key, 2003) and
diabetes (Tonstad, Stewart et al., 2013). Both vegan and vegetarian
diets may lower the risk of certain cancers such as colon (Fraser,
1999), stomach (Key, Appleby, Spencer, Travis, Allen et al., 2009),
female (Tantamango-Bartley, Jaceldo-Siegl, Fan, & Fraser, 2013), and
prostate (Fraser, 1999) cancers. Risk of diverticular disease for vegans
was only a quarter of that of omnivores (Crowe, Appleby, Allen, &
Key, 2011) while risk for hypothyroidism was 10% lower than omnivore risk (Tonstad, Nathan, Oda, & Fraser, 2013). In the Adventist
Health Study 2 (Orlich et al., 2013), the largest study of the health

32

C. Radnitz et al./Appetite 90 (2015) 31–36

effects of vegetarian and vegan diets, the overall death rate for vegans
was reduced 15%, which approached statistical significance. However,
in other studies with smaller samples (e.g. Burr & Sweetnam, 1982;
Key et al., 1998; Key, Appleby, Spencer, Travis, Roddam et al., 2009)
there was no survival advantage for those following a vegan diet.
While reduced mortality has not yet been shown for the vegan diet,
it is clear that substantial health benefits may accrue to those
adhering to it.
Foods consumed on a vegan diet are diverse and not always
healthful. They can include fruits, vegetables, legumes, nuts, seeds,
healthy fats, and whole grains, with documented health advantages (Key et al., 2006; Spencer et al., 2003). At the same time, grainbased foods high in sugar, salt and unhealthy fats can be vegan. This
raises the question of whether the health advantages of a vegan diet
result from just avoiding animal products, or from an overall concern
for health that includes choosing nutritious foods and engaging in
other health-promoting behaviors. In fact, if choosing a vegan diet
is linked to engaging in healthier behaviors overall, then these factors
should be investigated and accounted for in future studies.
Other researchers have noted that people following a vegan diet
may choose to do so for different reasons, which in turn, may affect
their food and lifestyle choices (Dyett, Sabaté, Haddad, Rajaram, &
Shavlik, 2013). These reasons include health, animal rights (ethics),
environmental concern, influence of others, and sensory disgust, with
health and ethical considerations emerging as the most often cited
reasons. Both quantitative and qualitative research has shown that
health and ethical reasons were most often cited for choosing to
follow a vegan diet (Dyett et al., 2013; Ruby, 2012).
In the current study, our objective was to investigate reasons for
choosing a vegan diet and associations with a wide range of health
and lifestyle factors in a large international sample of individuals
following a vegan diet. We hypothesized that those choosing a vegan
diet for health reasons would be more likely to engage in other
healthy behaviors, which could affect their health and nutritional
status.
Materials and methods
Participants
Participants were solicited through events targeting vegans (e.g.
festivals and social gatherings) or through social media (e.g. Facebook groups). To be included, participants had to affirm that they
were between the ages of 25 and 60, and that they consumed a
strictly vegan diet as indicated by answering “none” to a multiplechoice question asking which animal foods they consumed at least
monthly. Three hundred fourteen individuals began the survey, and
302 finished it, with complete data available for 246 individuals.
Participants were excluded from data analyses if they were under
the age of 25 or over the age of 60, if they indicated they had a debilitating chronic disease, or if they reported consuming animal foods
at least monthly or took a fish oil supplement.
Recruitment notices described participation in a study examining diet and lifestyle factors. For those interested, a link accessed
an online survey delivered by SurveyMonkey® where they reviewed an IRB-approved informed consent form before completing
the survey questions.
Measures
To assess the reason for following a vegan diet, a survey question asked participants to rank order their motivations for choosing
their diet pattern, selecting their primary reason from several options
including religious beliefs, health benefits, family influences, ethical
concerns (animal rights), environmental reasons, sensory disgust,
weight loss, introduction in early childhood, or other. Other survey

questions asked about health behaviors, specifically cigarette
smoking (yes/no), alcohol intake (number of standard drinks consumed weekly), sleep (average number of hours per night), exercise
(number of times they engaged in moderate and strenuous exercise per week; Godin & Shephard, 1985), work (average number of
hours spent in work or schoolwork each week), prescription medication (checked if taken for allergies, anemia, anxiety, low mood,
ADD, menstrual or GI), and supplement use. Participants also indicated whether they had engaged in the following mind–body
practices in the past week: yoga, tai chi, qi gong, Pilates, or
meditation.
Participants also completed the Depression Anxiety Stress Scales21 (DASS; Crawford & Henry, 2003), a brief measure of three negative
affective states (depression, anxiety, and stress). The social support
variable was derived from the Multidimensional Perceived Social
Support Scale (Zimet, Dahlem, Zimet, & Farley, 1988). To reduce the
respondent burden of an extensive survey, we chose three questions representative of each of the support domains: family, friends,
and significant others. Responses indicating the level of agreement on a 7-point Likert scale were summed to create a composite
social support measure.
For specific diet questions, we focused on foods that have been shown
to have health benefits (e.g. soy, omega-3 fatty acids, vitamin D, and
fruits and vegetables; Anderson, Smith, & Washnock, 1999; Liu, 2003)
or harmful effects (e.g. sugary soda, sweets; Hu & Malik, 2010). We also
focused on foods high in polyphenols as these phytochemicals are particularly beneficial due to their antioxidant and anti-inflammatory
bioactivity (Arts & Hollman, 2005). We used standard medium portion
sizes from the USDA National Nutrient Database (see Supplementary
Table S1). Participants were asked questions adapted from the EPICOxford study (Spencer et al., 2003). Specifically, they recorded estimated
average daily intakes of fruits, vegetables (excluding potatoes and corn),
and sweets. They also recorded monthly intakes of plant sources of
vitamin D (fortified milk substitutes + button mushrooms), as well as
the following select foods that are among the highest in polyphenol
content (Pérez-Jiménez, Neveu, Vos, & Scalbert, 2010): soy (miso + soy
flour + soybeans
+ soy yogurt + soy milk + tempeh + tofu), fruits (apple + blackberries + blueberries + cherries + dark plum + dried fruit + grapes
+ raspberries + strawberries), juices (grapefruit juice + apple juice + blueberry juice + pomegranate juice), fruits and juices (total fruits + total
juices), beverages (total juices + teas + coffee + cocoa + red wine), high
omega-3 plant foods (canola oil + flaxseed oil + flaxseeds + chia
seeds + walnuts), and high omega-6 plant foods (corn oil + grapeseed
oil + safflower oil + sunflower oil).
Results
Data were analyzed using nonparametric statistical tests due to
unequal sample sizes. Mann–Whitney U tests were conducted to
compare those following a vegan diet for ethical (ETH) and health
(HEA) reasons on diet duration, DASS-21 scores, BMI, exercise patterns, hours worked per week, hours spent outdoors per week, sleep,
social support, alcohol intake, and food consumption patterns. Effect
size was calculated for significant variables using Pearson’s r.
Chi-square analyses were conducted to compare participants on
supplement intake, medication use, being on a weight-reducing diet,
engagement in mind–body practice, and cigarette smoking. Cramer’s V was then calculated as a measure of effect size for significant
variables.
Health benefits (n = 45) and ethical concerns (n = 201) were, by
far, the most often cited reasons for choosing the vegan diet. The
sample was predominantly female, with the majority of individuals reporting Caucasian descent (see Table 1 for demographic data).
Almost two thirds were from the U.S. There was no significant difference between groups in BMI. The majority of participants were

C. Radnitz et al./Appetite 90 (2015) 31–36

Table 3
Differences in food and beverage intake in ETH and HEA vegans.

Table 1
Demographics by reason for maintaining a vegan diet.

Age
Gender
Male
Female
Country
US
Canada
Other
State/Province
Western US
Midwestern US
Northeastern US
Southwestern US
Southeastern US
Eastern Canada
Western Canada
Marital status
Single
Married
Divorced
Widowed
Cohabitating
Ethnicity
Hispanic
Black
American Indian/Alaska Native
White
Asian
Middle Eastern
Mixed
Education (years beyond high school)

Ethical

Health

37.78 (10.22)

35.11 (10.04)

24
77

31
69

60
9
31

71
4
24

22
13
30
10
13
10
4

22
31
19
6
16
0
6

34
33
13
1
20

53
33
2
0
11

4
0
1
91
0
1
3
4.48 (2.68)

4
4
0
77
2
0
13
4.91 (2.41)

Table 2
Lifestyle differences in ETH and HEA vegans.

Diet duration (years)*
DASS-21 Depression score
DASS-21 Anxiety score
DASS-21 Stress score
DASS-21 Total score
BMI
Moderate exercise/week
Strenuous exercise/week
Hours worked/week
Hours outdoors/week
Sleep (hours/night)
Social support – Special person
Social support – Emotional
support
Social support – Friends
Social support – Composite

HEA

246
245
244
245
240
246
246
246
246
246
246
246
246
244
246

ETH

HEA

U

M

SD

M

SD

3.20
2.76
0.69
1.46
2.79
43.72
47.79
59.71
10.40
70.11
90.96
28.44
201.15
7.72
28.65

1.70
2.03
0.82
1.03
4.56
44.73
43.76
95.36
43.40
131.98
88.18
56.23
215.98
13.53
29.01

3.76
3.69
0.53
1.34
1.56
24.91
38.51
81.99
6.97
88.96
55.16
26.11
177.78
5.67
34.39

2.00
2.66
1.24
0.78
2.20
25.92
45.79
78.32
10.35
83.47
49.96
26.31
111.62
7.44
38.91

3798.00
3503.00
3347.00
4244.00
3555.00
2936.00
3441.00
3409.00
4034.00
3556.00
3124.50
4460.00
4189.00
3972.50
4280.50

Notes: See methods for list of foods/beverages within combined variables.
Actual values versus mean rank values shown. r = −0.01 for all significant variables.
* Indicates significance at the p ≤ 0.05 level.
** Indicates significance at the p ≤ 0.01 level.

normal weight (60.43%), 6.38% were underweight while 24.26% of
the sample reported a BMI in the overweight range, and 8.94%
were obese.
HEA reported less stress (numerically) as measured by the DASSStress subscale compared to ETH; however, the difference was not
significant (see Table 2). ETH also reported a significantly longer duration on the diet than did HEA (U = 3137.00, p < 0.01). No other
significant differences were obtained for non-diet related lifestyle
comparisons analyzed using Mann–Whitney U tests.
Mann–Whitney U tests were conducted for the ETH and HEA
groups to compare the frequency with which they consumed certain
categories of foods (see Table 3). ETH reported consuming soy-

ETH

n

Vegetables/day
Fruits/day*
Sweets/day**
Soda/day
Alcohol servings/week
Soy foods/month**
Vitamin D foods/month**
Fruits/month**
Juices/month
Fruit and juice/month*
Beverages/month**
High-poly food/month
Total high-poly/month
High omega-6/month
High omega-3/month

Note: Shown are means (SD) or percentage of participants.

n

33

based foods (U = 2936.00, p < 0.01), foods high in vitamin D
(U = 3441.00, p = 0.01), and select beverages high in polyphenols
(U = 3124.50, p < 0.01) more frequently per month, whereas HEA
consumed select fruits and fruit juice more frequently per month
(U = 3556.00, p = 0.03) and select fruits more frequently per day
(U = 3503.00, p = 0.02). ETH also reported significantly greater consumption of sweets per day (U = 3347.00, p < 0.01) compared to HEA.
There was a trend for ETH to consume more alcohol standard drinks
per week compared to HEA and for HEA to consume more vegetables per day compared to ETH; however, these tests were not
significant (see Table 3). Pearson’s r statistics were calculated for
significant findings yielding a small effect size for all significant
findings (Cohen, 1992).
We calculated Chi square statistics for the ETH and HEA samples
(see Table 4) on measures of weight-reducing diet practices, cigarette smoking, mind–body practices, and medication and supplement
ingestion, and found that ETH reported a significantly higher likelihood of taking a multivitamin (p < 0.01), a supplement (p < 0.01),
a vitamin D supplement (p = 0.04), and a vitamin B12 supplement
(p = 0.03). We calculated effect size estimates (see Table 4) for significant comparisons finding a small effect size for the multivitamin,
vitamin D, and vitamin B12 supplement comparisons (based on
guidelines established by Rea & Parker (1992) for interpreting
Cramer’s V), and a moderate effect size for the supplement use
comparison.

U

M

SD

M

SD

244
246
246
246
246
235
212
203
243
242
245
245
245

8.01
6.20
3.21
8.06
17.47
24.08
4.52
2.20
35.22
10.85
7.11
5.41
4.82

8.18
7.74
4.14
6.85
15.71
4.65
3.99
2.19
34.31
10.70
0.99
2.04
1.96

5.57
4.89
3.73
6.00
14.62
23.81
5.83
2.61
33.30
11.84
7.22
4.82
4.82

7.57
6.38
4.82
5.33
14.08
5.53
5.17
2.09
17.04
11.01
0.93
1.96
2.10

3137.00
4061.50
4187.00
3736.00
4010.50
3863.00
2716.50
2732.50
4373.00
4147.00
4211.00
4406.50
4454.00

244
245

5.24
17.47

1.68
15.71

5.31
14.62

1.94
14.08

4100.00
4130.50

Notes: Actual values versus mean rank values shown.
* Indicates significance at the p ≤ 0.01 level. r = −0.01 for diet duration.

Table 4
Supplement use, mind–body practice, smoking and dieting in ETH and HEA vegans.
ETH
Absent
Weight-reducing diet
(last year)
Currently smokes
Mind–body practice
Multivitamin use**
No supplement use**
Alga supplement
Psych supplement
Vit D supplement*
Vit B12 supplement*

χ2

HEA
Present

Absent

147

52

36

9

0.74

180
119
141
165
176
200
127
73

19
80
60
36
25
1
74
128

41
26
41
27
43
44
36
24

4
18
4
18
2
1
9
21

0.02
0.01
8.39
10.47
2.40
1.36
4.65
4.46

* Indicates significance at the p ≤ 0.05 level.
** Indicates significance at the p ≤ 0.01 level.

V

Present



0.19
0.21


0.14
0.14

34

C. Radnitz et al./Appetite 90 (2015) 31–36

Discussion
To summarize, compared to the HEA group, the ETH group reported being on a vegan diet longer, consuming greater quantities
of soy, select foods high in vitamin D, sweets per day, select beverages high in polyphenols and vitamin supplements. Conversely,
the HEA sample reported consuming significantly more select fruits
and fruit juices high in polyphenols than did the ETH sample.
In our sample, the ETH participants had remained on the diet significantly longer than the HEA participants, a result consistent with
that found by others (Hoffman, Stallings, Bessinger, & Brooks, 2013).
Indeed, in a recent study (Asher et al., 2014) of both current and
former vegetarians, a wider range of motivations for adopting a vegetarian diet was cited by current vegetarians, whereas the only reason
for adopting the diet cited by a majority of the former vegetarians
sampled was health concerns. In this study, 68% of current vegetarians cited animal protection as a reason for diet adoption versus only
27% of former vegetarians, a finding suggestive of a robust association between concern for animals and remaining vegetarian.
There appears to be different trajectories for becoming vegetarian due to health and ethical reasons with both groups of vegetarians
more likely to transition to veganism for ethical reasons (Jabs, Devine,
& Sobal, 1998). Those choosing a vegetarian diet for moral reasons
reported greater disgust with meat and a more intense emotional
reaction to meat consumption compared to those who became vegetarian for health reasons (Rozin, Markwith, & Stoess, 1997).
Consistent with the more intense emotional reaction to meat reported by Rozin et al. (1997) was our finding (approaching
significance) that compared to the HEA group, the ETH group reported more overall stress. We can hypothesize that this more intense
emotional reaction to meat might motivate a quicker transition to
veganism, which may account for the finding of longer duration on
the diet among those citing ethical reasons. As both the Jabs et al.
(1998) and Rozin et al. (1997) studies are now almost twenty years
old, we can speculate that the vegan transition may have been
delayed in the health vegans. Or, the more recent dietary transition was possibly motivated by the publication of additional research
showing the health benefits of the diet as well as the proliferation
of meat and dairy substitutes (annual increases between 2 and 8
percent; Ginsberg, n.d.) and more vegan options in restaurants. Alternatively, the advent of these events may have attracted greater
numbers of vegans choosing the diet for health reasons more recently. Large percentages of those choosing the diet for either reason
tended to remain on it after 3 years (VRG; Mangels, Brathwaite, &
Stahler, 2010), suggesting that once an initial time investment is
made, the diet becomes well entrenched.
Overall, we found a few notable significant differences in diet
quality between the two samples, albeit with small effects. Although substantial health benefits have been noted for soy-based
foods (Hu & Malik, 2010), other studies have cast doubt on their
health value (e.g. Setchell, 1998; Siegel-Itzkovich, 2005). A recent
review of the health effects of soy concluded that if minimally processed or fermented, there are likely beneficial effects including
protection from cancer, heart disease, and symptoms of menopause (D’Adamo & Sahin, 2014). At the same time, as there are antinutrients and by-products (e.g. hexane) involved in forming highly
processed soy, excessive consumption of these forms may have
harmful effects. There is less controversy regarding the health advantages of fruits (Liu, 2003; Mohindra, Nicklas, O’Neil, Yang, &
Berenson, 2009). Reviews of research have shown that they provide
a wide variety of vitamins, minerals, phytochemicals and fibers
(Liu, 2003), and that increased consumption is associated with health
benefits, namely, reduced incidence of coronary heart disease, type
2 diabetes, and obesity (Slavin & Lloyd, 2012).
Evidence for the health benefits of phytochemicals such as polyphenols has been accumulating during the past few decades

(Manach, Scalbert, Morand, Rémésy, & Jiménez, 2004) as they have
powerful properties that prevent chronic degenerative diseases such
as cancer and heart disease via mechanisms such as antioxidant function. In our analyses, the ETH sample reported greater consumption
of high polyphenol beverages than did the HEA sample, a finding
that would seem to conflict with our hypothesis. However, our
measure of beverages high in polyphenols was computed by
summing monthly intake of juices, teas, coffee, cocoa and red wine.
Although these drinks contain high levels of polyphenols, they also
have high levels of other substances that are considered less healthy,
for example, sugar (juices and cocoa), caffeine (coffee, tea, and cocoa)
and alcohol (red wine). Consequently, our sample of health vegans
may have chosen to consume lower levels of these beverages due
to concern over consumption of these other less healthy compounds.
In line with our hypothesis, we found that ethical vegans reported a greater intake of sweets than did health vegans. Although
the Dyett et al. (2013) study reported that their vegan sample consumed moderate amounts of desserts and sugar, they did not report
any comparisons between their health and ethical vegan samples.
High sugar intake has been linked to a wide array of adverse health
effects including obesity (Woodward-Lopez, Kao, & Ritchie, 2011),
type 2 diabetes (Greenwood et al., 2014), hypertension (Malik, Akram,
Shetty, Malik, & Yanchou Njike, 2014), cardio-metabolic disease
(Richelsen, 2013), and compromised oral health (Falco, 2001). In our
sample, the mean intake of daily sweets was .69 of a serving for
the ETH group and .53 for the HEA group, which is not excessive
and probably not indicative of a significant health risk.
We found that the ETH group was more likely to consume plant
foods high in vitamin D and take vitamin D supplements than the
HEA group, a finding contrary to what we hypothesized. To explain
the supplement finding, it is possible that individuals choosing a
vegan diet for health reasons are more focused on obtaining required nutrients from foods, and therefore did not feel the need to
use supplements. However, in this case, there would be an expectation that the vitamin D intake from foods for HEA would not be
significantly lower than that of ETH. Dyett et al. (2013) also examined vitamin D intake in persons following a vegan diet for ethical
and health reasons. However, they did not report any significant differences between the two groups, although the intake of both was
inadequate. Vegan diets may be lower in vitamin D than omnivore diets (Craig & Mangels, 2009), so eating more foods rich in
vitamin D and taking supplements could prevent a possible
deficiency.
In addition to vitamin D supplements, overall, ethical vegans were
more likely to take supplements including multi-vitamins and vitamin
B12. As mentioned before, it is possible that health vegans, in pursuit
of better health from food sources may have eschewed supplement
intake, believing that plant foods were a better source of essential nutrients. However, vegan diets provide insufficient amounts of B12 (Craig
& Mangels, 2009). Indicators of B12 deficiency (plasma methylmalonic
acid, homocysteine and holotranscobalamin II) have shown that vegans
have low levels of B12 (Key et al., 2006); however, relatively few report
clinical symptoms (Antony, 2003). Nonetheless, taking supplements or
consuming fortified foods (e.g. soymilk) would be important to prevent
deficiency.
We did not find a significant difference in BMI between the ETH
and HEA group. However, in the Dyett et al. (2013) study there were
more health than ethical vegans classified as overweight and obese.
In our sample, the proportion of overweight or obese participants
(33.5%) was numerically lower than in the general population in the
U.S. (69%) and Canada (60.5%), where most of our sample resided
(WHO, 2008).
As research accumulates investigating how reasons for choosing a vegan diet impacts food choices and other health behaviors,
we can begin to develop profiles of ETH and HEA sub-populations.
However, any interpretation of this research must acknowledge a

C. Radnitz et al./Appetite 90 (2015) 31–36

few caveats, namely, 1) that discrepancies among studies in how
data are gathered (populations sampled, methods of data gathering, questions posed) affect their results, 2) that there are differences
in how studies have grouped sub-samples, and 3) that only a few
studies to date (including ours) have investigated this question. Nonetheless, collectively, these studies have demonstrated that compared
to those choosing the diet for health reasons, those doing so for
ethical reasons are more strict in doing so and have been eating this
way for a longer period of time (Waldmann, Koschizke, Leitzmann,
& Hahn, 2003; present study). In addition, ethical vegans are more
likely to consume high fat foods (Dyett et al., 2013), soy foods
(present study), sweets (present study), high-polyphenol beverages (present study), vitamin D foods (present study) and
supplements (present study), but less likely to eat fruits (present
study). Also worth noting are the many non-significant findings in
all of the published reports, which suggests that among those following a vegan diet, diet motivation may have only limited impact
on food and other lifestyle choices.
The interpretation of these results should be considered in light
of a few limitations inherent in the design of the study and the survey
method we employed. The majority of participants were ethical
vegans. This should not be seen to reflect the proportion that actually chose the diet for ethical versus health reasons. We recruited
a convenience sample and our recruitment methods may have impacted the number of individuals we obtained in each group. At the
same time, the proportion of participants we obtained for each group
is consistent with those found in some studies (e.g. Fox & Ward,
2008; Hoffman et al., 2013; Jabs et al., 1998) although others (e.g.
Dyett et al., 2013; Waldmann et al., 2003) obtained samples that
were more equal. Nonetheless, across all studies, health benefits and
concern for animals were the two most frequently cited reasons for
choosing a vegan diet.
Although participants were divided according to the primary
reason for choosing the diet, other reasons may have also been important either initially, or over time when they became more aware
of the full array of consequences for their chosen diet (Ruby, 2012).
Also, in forming our variables, we attempted to use questions from
validated measures (e.g. for social support), but in some cases either
there were no validated measures for the lifestyle questions we
wanted to ask or adding multi-item measures would have lengthened the survey too much. In several instances, we utilized single
items to measure variables as studies have shown that single item
measures with high face validity are valid when compared to multiitem scales (Abdel-Khalek, 2006; Dollinger & Malmquist, 2009). In
the interest of reducing participant burden, we also did not use a
complete food frequency questionnaire, but instead inquired about
foods that research has shown were most predictive of health, either
positively or negatively, such as fruits and sweets (Key et al., 2006;
Parletta, Milte, & Meyer, 2013; Spencer et al., 2003; Wahlqvist & Lee,
2006).
Conclusions
The substantial increase observed during the past few years in
the number of individuals following a vegan diet in some locales
may indicate that for a portion of the population we are approaching a historic transition point to veganism driven by greater
awareness of animal abuse, accumulation of research demonstrating the health benefits of a vegan diet, and a substantial increase
in the availability of meat and dairy substitutes. Consequently,
understanding the health implications of how the diet is followed
seems more important. Some of our findings supported our hypothesis that compared to those choosing the diet for ethical reasons,
those choosing it for health reasons would make other healthier
choices. The HEA group consumed more fruit and fewer sweets than
the ETH group. On the other hand, the ETH group reported greater

35

consumption of foods and supplements when the healthy option
was not as obvious (e.g. soy, supplements) which may explain the
seemingly contrary findings. Our results stand in contrast to those
reported in the Dyett et al. (2013) article where the only difference in food consumption between health and ethical vegans was
that ethical vegans reported significantly greater intake of high fat
foods. At this point, there is little research into specific foods consumed on this diet; therefore, more studies are needed to further
elucidate dietary differences between subgroups following a vegan
diet as differences may affect health and nutrition outcomes.

Appendix: Supplementary material
Supplementary data to this article can be found online at
doi:10.1016/j.appet.2015.02.026.

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