Adopting vegetarian and vegan eating patterns: Associations with disordered eating behaviors among young adult college students

Abstract

Introduction

Vegan and vegetarian diets are increasingly popular, though there is concern that disordered eating can drive, emerge, or intensify from the choice to adopt dietary restrictions.

Objective

We sought to ascertain whether disordered eating or weight-control behaviors are associated with newly adopting a vegetarian/vegan diet during college and to assess symptom awareness and treatment utilization.

Methods

Data came from 11,503 students in the Healthy Minds Study spanning 2015–2021. We examined associations between (i) the SCOFF eating disorder screener and (ii) symptom-specific items from the Eating Disorder Examination Questionnaire, and recent adoption of a vegan/vegetarian diet. Participants’ knowledge of eating disorder symptoms and experiences with treatment utilization were also assessed.

Results

Five-hundred thirty-two participants (~5%) reported adopting a vegan/vegetarian diet. Compared to students who did not change eating patterns, those who adopted vegetarianism/veganism had higher past-month prevalence of binge eating (25% vs, 16%), compulsive exercise (18% vs. 9%), and fasting (12% vs. 8%). Each behavior was significantly associated with greater odds of having recently adopted a vegetarian/vegan diet. A positive SCOFF screen (2+ items) was associated with 1.79-times (95% CI: 1.48, 2.16) greater odds of newly adopting a vegetarian/vegan diet. There were no observed differences between groups with respect to knowledge of eating disorder symptoms or treatment-seeking attitudes and behaviors.

Discussion

Disordered eating or weight-control behaviors were prevalent in this population of young adults and were associated with adopting a vegetarian/vegan diet, though awareness and help-seeking were not elevated among those with higher eating disorder risk.

1. Introduction

Vegan and vegetarian eating patterns are increasingly popular for a variety of reasons, including personal health goals and ethical and environmental considerations (Dhont, 2024; Hargreaves, 2021; de Boer, 2017; Heiss, 2017; Rosenfeld, 2017; Radnitz, 2015). Vegan/vegetarian diets are classified according to which foods are included in the eating pattern (Table 1). While adopting a vegan/vegetarian diet can be done in a nourishing, nutritionally adequate, and health-supporting way (Heiss, 2017; Bakaloudi, 2021; Dinu, 2017; Robinson-O’Brien, 2009; Kent 2022), there is concern that disordered eating or unsafe weight-control behaviors can drive, emerge, or intensify from the choice to restrict animal-based foods (Fuller, 2022; Zickgraf, 2020).

Table 1.

Definitions of vegan and vegetarian dietary patterns.

Vegan 1	Does not consume any meat or animal-derived products
Vegetarian 1	Does not eat meat, poultry, or fish
Lacto-ovo vegetarian	Eats both eggs and milk/dairy products
Lacto-vegetarian	Eats milk or dairy products, but not eggs
Ovo-vegetarian	Eats eggs, but not milk or dairy products
Pescetarian 2	Avoids meat and poultry, but may eat fish and seafood, eggs, and milk or dairy products
Semi-vegetarian 2	Mostly follows a vegetarian eating pattern but may eat meat, poultry, or fish (usually infrequently)
Plant-based3 eating pattern	Limits but may not formally restrict specific animal-based foods and emphasizes increased intake of plant-based foods including grains, fruits, vegetables, legumes, and nuts. As an umbrella term, plant-based eating patterns can include the more formal vegan and vegetarian eating patterns defined above.

¹Academy of Nutrition and Dietetics (Melina, 2016)

²See Zickgraf (2020)

³See Storz (2022)

Previous research exploring disordered eating in the context of vegetarian diets has produced inconsistent results. Studies evaluating participants with existing eating pathology or eating disorder (ED) diagnoses found higher prevalence of vegan/vegetarian diets compared to individuals without disordered eating (Mathieu, 2023; Sergentanis, 2020; Bardone-Cone, 2012; Zuromski, 2015), and researchers hypothesized that vegan/vegetarian dietary restrictions may function as a socially acceptable weight-control strategy (Gilbody, 1999; Bardone-Cone, 2012). Studies in non-clinical populations have explored associations between vegan/vegetarian diets and eating pathology and found that among young adults who report following vegetarian diets, disordered eating behaviors (DEB) are more prevalent, particularly among semi-vegetarians and those who report adopting vegetarian patterns stemming from weight or health concerns (Zickgraf, 2020; Sieke, 2022).

However, not all studies suggest a significant association between disordered eating and vegetarian diet patterns (Bialek-Drwarta, 2024; Dorard, 2021); one recent study reported no differences (as measured by the EAT-26) between vegetarians and omnivores (Dorard, 2021). Another study comparing vegans’ eating behaviors to omnivores’ found vegans had lower eating pathology as measured by the Eating Disorder Examination Questionnaire (EDE-Q); yet compared to vegans, vegetarians and semi-vegetarians may be more vulnerable to disordered eating (Heiss, 2017).

A limitation of these studies is the relatively small number of participants included (McLean, 2022a); underpowered analyses may be a potential contributor to conflicting findings. A second concern is that assessment and screening tools for eating pathology broadly conceptualized may flag normal meat-avoiding behaviors among vegans and vegetarians as restriction, labeling as eating pathology what may be normative or appropriate for this population (McLean, 2022a, 2022b). The resulting potential for misclassification may contribute further to the mixed study findings reported in the literature. Therefore, it is important to research not just eating pathology as a catch-all categorization but to investigate defined and specific disordered eating behaviors. Previous research also focused heavily on associations between vegetarian diets and anorexia nervosa (AN) and restriction. When binge eating behaviors specifically were included, analyses were again mixed: one recent study found no association between vegetarian diets and binge eating (Sieke, 2022), while a second study found emotional and dysfunctional eating behaviors were more prevalent in vegetarian participants at higher body weights compared to “normal-weight” omnivores (Hanras, 2022). There is a need to better understand potential associations between vegan/vegetarian eating patterns and the full spectrum of ED symptoms. Additionally, research is needed to consider the extent to which a broad range of disordered eating symptoms exists at subclinical levels where dietary restriction, binge eating, and/or compensatory calorie-purging behaviors are present. Subclinical DEBs can increase risk for full-syndrome EDs and adverse physiological outcomes (Field, 2012; Lipson, 2020; Striegel-Moore, 2007; Thein-Nissenbaum, 2011).

Adolescence and young adulthood are periods of increased risk for the development of DEB and unsafe weight-management behaviors (Goldschmidt 2016; Grammer 2020; Hudson 2007). EDs frequently go undetected, and treatment is underutilized (Hart, 2011; Lipson 2021). It is also a time when young adults acquire more agency and explore new eating patterns and identities (Cao, 2023; Powell, 2019; Stok, 2018; Kemper, 2021). In the case of moving towards plant-based eating patterns, increased individual control regarding eating choices as well as environments and social structures that facilitate experimentation have been identified as relevant factors (Kemper, 2021). For many emerging adults, college is a transitional window with a marked increase in independence around food decision-making and changes in diet patterns (Maillet, 2021); it is a critical time to establish dietary patterns and eating behaviors that support well-being.

Thus, emerging and young adulthood may be typified by new and intersecting eating behaviors, pointing to both a unique phase of vulnerability but also one ripe for targeted supports and interventions (Zickgraf, 2020; Poobalan, 2014; Eguren-Garcia, 2024; Hutchesson, 2022). Research suggests that primary barriers to care for young adults include limited mental health literacy, concerns about the process of help-seeking (e.g., confidentiality, stigma) and lack of knowledge of help available (Radez, 2021; Nicula, 2022; Marinucci, 2022). If a clear association between DEB and newly adopting a vegan/vegetarian diet pattern in young adulthood is identified, the rationale for interventions aimed at improving mental health literacy and reducing barriers to seeking and accessing effective eating disorder treatment can fuel targeted strategies on college campuses.

This study uses data from the Healthy Minds Study (HMS)—a large, annual, cross-sectional survey of U.S. college and university students—to explore associations between vegan/vegetarian eating patterns, DEB, and unsafe weight-control behaviors. The aim of this study is to address limitations of previous studies that have yielded conflicting findings by assessing, in a large sample, associations between college students’ newly adopting vegan/vegetarian diets with (1) eating pathology broadly defined (2) individual disordered eating and weight-control behaviors, as well as (3) specific eating disorder diagnoses. We further sought to characterize the extent to which weight concern is present across subgroups of university students. Finally, we assessed potential implications regarding awareness of behavioral symptoms (mental health literacy) and treatment utilization. We hypothesized that young adults’ choice to newly adopt a vegan/vegetarian eating pattern would be associated with eating pathology and with individual disordered eating behaviors. If adopting vegan/vegetarian eating inadvertently drove the emergence of disordered eating, we further hypothesized that students who newly adopted a vegan/vegetarian diet and experienced disordered eating may be less likely to know about symptoms of eating disorders or know where on campus to seek support.

2. Methods

HMS is an online survey examining mental health among U.S. college and university students. Participating academic institutions are diverse across campus characteristics; there were no exclusion criteria limiting which academic institutions could participate. There were no student-level exclusion criteria apart from requiring participants be ≥18 years old. Data were collected using Qualtrics, and students were recruited by email with personalized links leading to a secure landing page with informed consent information. Student participation was voluntary and incentivized via eligibility for one of several gift card prizes. Institutional Review Board approval was obtained from all institutions. Details regarding HMS study design have been documented previously (Lipson, 2019; Lipson, 2022; Lipson, 2023; Gordon, 2023).

This study analyzed data from 6 waves of HMS (Fall 2015 - Spring 2021). We limited our sample to participants who answered questions about adopting vegan/vegetarian eating patterns and DEB.

2.1. Measures

2.1.1. Vegan/Vegetarian Eating Pattern

Binary classification of newly adopting a vegan/vegetarian diet in college was determined by selecting “I became vegetarian/vegan” as one of the response options to the question “How have your eating habits changed since you began as a student at your school?” Thus, this classification does not include students who were already vegan/vegetarian prior to starting school, nor does it separate vegan and vegetarian participants into separate and distinct categories. Further, to focus the analysis on emerging and young adults, participants with age ≥ 30 years were excluded.

2.1.2. Disordered Eating Behaviors

Eating pathology was assessed using the SCOFF screener and individual EDE-Q questions. The SCOFF is a five-item tool to screen for ED symptoms (Morgan, 2000) by asking about (i) making oneself sick due to uncomfortable fullness, (ii) worrying about loss of control over eating, (iii) weight loss (losing ≥14 pounds over a 3-month period), (iv) perceiving oneself as fat when others perceive being too thin, and (v) feeling that food dominates one’s life. Scores range from 0 to 5, with ≥2 constituting a positive screen; prior studies identify this cutoff as both sensitive and specific (Luck, 2002; Morgan, 1999). This threshold better accounts for binge eating and restrictive eating patterns without weight loss (or occurring at higher body weights) that may not be flagged as positive screens using higher thresholds (i.e. ≥3 items).

DEBs were assessed using six questions from the EDE-Q, which asks participants about the frequency of behaviors over the previous four weeks (Fairburn, 2008). Five questions asked about purging behaviors for weight- or shape-control including (i) self-induced vomiting, (ii) taking laxatives, (iii) diuretics or diet pills, (iv) “driven or compulsive” exercise to burn calories, and (v) non-religious fasting (“intentionally not eating anything at all for at least 8 waking hours”). Binge eating was measured with the question, “on how many days have you eaten an unusually large amount of food and have had a sense of loss of control at the time?” The two questions for laxative use and diet pills/diuretics were collapsed into a single variable to improve statistical power. Response frequencies range between 0 and 28 days. DEBs were categorized as: never, less than weekly (1–3 days), and weekly or more often (≥4 days). More than one DEB could be reported by any given participant.

HMS also included the five-item Weight Concern Scale (WCS), an instrument designed to assess fear of weight gain, concerns about body weight and shape, and dieting history (Killen, 1996; Brasil, 2022). WCS scores range from 5 to 26, with higher scores indicating greater concern about weight and shape.

2.1.3. ED Diagnoses

The presence of an ED diagnosis was ascertained based on self-report. HMS asked participants if they had “ever been diagnosed with any of the following conditions by a health professional (e.g., primary care doctor, psychiatrist, psychologist, etc.),” allowing multiple selections from a list that included “eating disorder.” Students who reported an ED diagnosis were then asked to indicate their specific diagnosis, with response options including AN, bulimia nervosa (BN), binge eating disorder (BED), avoidant/restrictive intake disorder, “Other,” and “Don’t know.”

2.1.4. Mental Health Literacy: Knowledge of ED Symptoms and Help-Seeking Knowledge and Experiences

HMS surveys asked, “as far as you know, which of the following are common symptoms of eating disorders?” with response options including (i) dramatic weight loss, (ii) restrictive eating/fasting, (iii) self-induced vomiting, abuse of laxatives, diet pills and/or diuretics, (iv) rapid, uninterruptible speech (an intentionally incorrect response), and (v) eating an unusually large amount of food while feeling out of control.

In the subset of participants who reported experiencing DEB weekly or more often, we evaluated attitudes related to seeking mental health treatment with three questions utilizing a six-point Likert-based scale ranging from “strongly agree” to “strongly disagree.” Participants who responded either “strongly agree” or “agree” were classified as endorsing/agreeing with a particular question. Knowledge of campus mental health services was assessed based on agreement with the statement, “If I needed to seek professional help for my mental or emotional health, I would know where to access resources from my school.” Perceived need for mental health support was assessed with the statement, “In the past 12 months, I needed help for emotional or mental health problems such as feeling sad, blue, anxious, or nervous,” and a nested question asked about current need for mental health support. Experience with counseling or therapy for mental health concerns was also assessed, with response options being never, only prior to starting college, and during/since starting.

2.1.5. Academic Program and Demographic Characteristics

Participants self-reported age, race, Hispanic ethnicity, gender identity, and sexual orientation, with multiple response options allowed for individuals holding multiple identities. We modeled gender identity as a three-component categorical variable: women, men, and gender minority, defined as transgender, genderqueer, gender nonconforming, or questioning. Students self-reported academic characteristics including enrollment status (full vs. part time), degree program, participation in athletics, and living situation.

2.2. Statistical Analyses

Analyses were conducted with R software version 4.3.1. Descriptive statistics illustrate the proportion of participant responses across the SCOFF screen, EDE-Q, WCS, and ED diagnoses. To assess for associations between adopting a vegan/vegetarian eating pattern in college and DEB/unsafe weight-control behaviors, we fit multivariate models using overall SCOFF scores (continuous) and a positive SCOFF screen (binary). To assess associations with individual DEBs, we fit models for each behavior, comparing students who reported no behavior use (“never”, the reference group) to students who reported binge eating 1–3 days/month, and weekly or more often (4–7+ days/month). For binge eating behaviors, we conducted a sensitivity analysis evaluating associations with vegan/vegetarian diets among the subset of participants who reported binge eating without also reporting fasting or calorie-purging compensatory behaviors (i.e., where binge eating is the only reported DEB). Finally, we modeled associations with individual ED diagnoses as well as potentially undiagnosed cases, defined as individuals reporting DEB (≥ weekly, as this frequency aligns with diagnostic criteria (APA, 2013) but without a self-reported ED diagnosis.

Covariates in all models included race (White, Asian, Black, another race identity or multiracial), Hispanic ethnicity, fulltime enrollment status, athlete status, and residence (on-campus dorm, on-campus suite- or apartment-style housing, fraternity/sorority, off-campus house/apartment, off-campus with family, or other living arrangement). We assessed for, but did not detect, effect modification by gender identity, race identity, and residence. We used analysis of variance (ANOVA) and Tukey’s Honest Significant Difference test to assess between-group differences for WCS scores. Chi-square tests were used for between-group comparisons for ED symptom knowledge and treatment-seeking.

3. Results

The sample included 11,503 students (Supplementary Figure 1); sample characteristics are shown in Table 2. Participants’ mean age was 21.2 years, and 77.1% of respondents were in Associate’s or Bachelor’s degree programs. Overall, 4.6% of students (n=532) reported adopting a vegan/vegetarian eating pattern in college.

Table 2.

Sample characteristics, stratified by adoption of a vegan or vegetarian eating pattern in college.

	Overall sample	Became vegan/vegetarian	Did not become vegan/vegetarian
	n = 11,503	n = 532 (4.6%)	n = 10,971 (95.4%)
Age, years
Mean (standard deviation)	21.2 (2.7)	20.8 (2.1)	21.2 (2.7)
Gender identity, n (%)
Men	3,892 (33.8)	94 (17.7)	3,798 (34.6)
Women	7,420 (64.5)	423 (79.5)	6,997 (63.8)
Gender minority	191 (1.7)	15 (2.8)	176 (1.6)
Race, n (%) (multiple selections possible)
American	176 (1.5)	10 (1.9)	166 (1.5)
Indian/Alaska Native	243 (2.1)	11 (2.1)	232 (2.1)
Arab/Middle Eastern	1,987 (17.3)	46 (8.6)	1,941 (17.7)
Asian	695 (6.0)	46 (8.6)	649 (5.9)
Black or African American	111 (9.6)	1 (0.2)	110 (1.0)
Hawaiian/Pacific Islander	8,534 (74.2)	440 (82.7)	8,094 (73.8)
White	1,183 (10.3)	51 (9.6)	1,132 (10.3)
Hispanic ethnicity, n (%)
Sexual orientation, n (%)
Heterosexual	9,543 (83.0)	362 (68.0)	9,181 (83.7)
Bisexual	756 (6.6)	64 (12.0)	692 (6.3)
Gay or lesbian	731 (6.4)	60 (11.3)	671 (6.1)
Queer	231 (2.0)	36 (6.8)	195 (1.8)
Another sexual orientation	389 (3.4)	27 (5.1)	362 (3.3)
Athlete status, n (%)
Club or intramural sports	488 (4.2)	11 (2.1)	477 (4.3)
Varsity sports	310 (2.7)	10 (1.9)	300 (2.7)
Enrollment status, n (%)
Full-time student	11,025 (95.8)	513 (96.4)	10,512 (95.8)
Degree Program, n (%)
Associate’s degree	172 (1.5)	6 (1.1)	166 (1.5)
Bachelor’s degree	8,700 (75.6)	447 (84.0)	8,253 (75.2)
Master’s degree	1,375 (12.0)	45 (8.5)	1,330 (12.1)
Professional degree or PhD	1,125 (97.8)	30 (5.6)	1,095 (10.0)
Non-degree or other	131 (1.1)	4 (0.8)	127 (1.2)
Place of residence, n (%)
On-campus residence hall	4,442 (38.6)	201 (37.8)	4,241 (38.7)
On-campus apartment	966 (8.4)	56 (10.5)	910 (8.3)
Fraternity or sorority	228 (2.0)	3 (0.6)	225 (2.1)
Off-campus housing	4,858 (42.2)	238 (44.7)	4,620 (42.1)
With family/relatives	879 (7.6)	27 (5.1)	852 (7.8)
Other housing arrangement	126 (11.0)	5 (0.9)	121 (1.1)

3.1. Associations Between Adopting Vegan/Vegetarian Diet and Disordered Eating Constructs

In the overall sample, 21.8% of participants had positive SCOFF screens (Table 3). Among those newly adopting vegan/vegetarian diets, the proportion who screened positive was 34.2%, compared to 21.2% of those who did not change this component of their diets. ED diagnoses were also present in higher proportions among those who became vegan/vegetarian, and this pattern was observed for all diagnoses.

Table 3.

Summary of SCOFF scores and proportion of participants reporting ED diagnoses and DEBs (n (%)).

	Overall	Became vegan/vegetarian	Did not become vegan/vegetarian	Test statistic1	p-value
	n = 11,503	n = 532	n = 10,971
SCOFF Questionnaire
Positive SCOFF screen	2,504 (21.8)	182 (34.2)	2,322 (21.2)	49.9 (1)	<.001
Mean score (SD)	0.79 (1.06)	1.17 (1.18)	0.79 (1.06)	−7.7 (571.9)	<.001
Individual Disordered Eating Behaviors
Fasting				25.9 (2)	<.001
Never	9,675 (84.1)	404 (75.9)	9,271 (84.5)
1–3 days	857 (7.5)	61 (11.5)	796 (7.3)
At least weekly (4+ days)	938 (8.2)	63 (11.8)	875 (8.0)
Binge eating episodes				32.3 (2)	<.001
Never	6,654 (57.8)	255 (47.9)	6,399 (58.3)
1–3 days	2,828 (24.6)	139 (26.1)	2,689 (24.5)
At least weekly (4+ days)	1,935 (16.8)	133 (25.0)	1,024 (16.4)
Purging2				32.5 (2)	<.001
Never	10,920 (94.9)	477 (89.7)	10,443 (95.2)
1–3 days	375 (3.3)	34 (6.4)	341 (3.1)
At least weekly (4+ days)	208 (1.8)	21 (3.9)	187 (1.7)
Compulsive exercise				47.1 (2)	<.001
Never	9,712 (84.4)	400 (75.2)	9,312 (84.9)
1–3 days	673 (5.9)	36 (6.8)	637 (5.8)
At least weekly (4+ days)	1,096 (9.5)	95 (17.9)	1,001 (9.1)
Any behavior (≥ weekly)	3,058 (26.6)	214 (40.2)	2,844 (25.9)	52.5 (1)	<.001
Self-Reported Eating Disorder Diagnoses
Anorexia nervosa	213 (1.9)	22 (4.1)	191 (1.7)	13.7 (1)	<.001
Bulimia nervosa	117 (1.0)	11 (2.1)	106 (1.0)	4.7 (1)	.031
Binge eating disorder	76 (0.7)	8 (1.5)	68 (0.6)		.024
Other eating disorder	35 (0.3)	5 (0.9)	30 (0.3)		.021
≥ weekly behaviors without self-reported ED diagnosis	2,850 (24.8)	189 (35.5)	2661 (24.3)	34.0 (1)	<.001

¹Statistical tests include Student’s t-test for continuous variables (reported as t-test statistic (df)), Chi-squared tests for categorical variables (reported as χ² (df)), except where small cell size warranted use of Fisher’s exact test (this was the case for binge eating disorder diagnosis and other eating disorder diagnosis)

²Purging behaviors include self-induced vomiting, laxative use, and diet pill use.

Past-month DEB was far more frequent than reported ED diagnoses. For example, while <1% of the sample reported a BED diagnosis, about 16% reported experiencing episodes of binge eating with loss of control at least weekly in the past month. Similarly, just under 2% reported AN diagnoses, while 8% reported fasting for weight/shape control at least weekly. Binge eating was, by far, the most frequently reported DEB, followed by compulsive exercise and fasting. All individual disordered eating behaviors, including fasting, purging, binge eating, and compulsive exercise, were associated with reporting having adopted vegan/vegetarian eating patterns since starting college (all p<.001).

In multivariate analyses, a positive SCOFF screen was associated with 1.79-times greater odds of having adopted a vegan/vegetarian eating pattern in college; the odds increased by 1.3 per each unit increase in SCOFF score (Table 4). Consistently, positive associations were found in analyses between individual DEBs and adoption of a vegan/vegetarian diet, and a dose-response relationship was observed for all behaviors such that engaging in DEBs more often was associated with greater likelihood of having reported newly adopting a vegan/vegetarian diet. Weekly occurrences of calorie-purging via self-induced vomiting, laxative or diet pill use, and compulsive exercise were all associated with an approximately two-times greater odds of having switched to vegan/vegetarian diets in college. Fasting and binge eating behaviors had smaller effect estimates, but both were statistically significant. In the sensitivity analysis, 1,483 (76.6%) of the 1,935 participants reporting binge eating episodes that occurred at least weekly did not experience concurrent purging/restricting behaviors; this behavior pattern (binge eating only) was associated with 1.62-times higher odds of having adopted a vegan/vegetarian diet in college (95% CI: 1.29, 2.02).

Table 4.

Associations (ORs) between disordered eating measures and adoption of a vegan or vegetarian diet in college (n = 11,503).

	Multivariate Model
	OR (95% CI)	p-value
SCOFF Questionnaire
Positive SCOFF screen	1.79 (1.48, 2.16)	<.001
Mean score (SD)	1.31 (1.22, 1.40)	<.001
Individual Behaviors
Fasting
Never	REF	--
1–3 times per month	1.55 (1.16, 2.05)	.002
Weekly or more often	1.50 (1.12, 1.96)	.004
p-for-trend		<.001
Binge eating
Never	REF	--
1–3 times per month	1.21 (0.97, 1.49)	.085
Weekly or more often	1.70 (1.36, 2.12)	<.001
p-for-trend		<.001
Self-induced vomiting
Never	REF	--
1–3 times per month	1.94 (1.27, 2.87)	.001
Weekly or more often	2.14 (1.07, 3.87)	.020
p-for-trend		.036
Laxatives, diet pills, diuretics
Never	REF	--
1–3 times per month	1.24 (0.58, 2.32)	.541
Weekly or more often	2.05 (1.06, 3.62)	.021
p-for-trend		.021
Compulsive exercise
Never	REF	--
1–3 times per month	1.18 (0.81, 1.65)	.370
Weekly or more often	2.03 (1.59, 2.56)	<.001
p-for-trend		<.001
Any behavior (≥ weekly)	1.78 (1.49, 2.14)	<.001
Eating disorder diagnosis
Anorexia Nervosa	1.92 (1.18, 2.98)	.006
Bulimia Nervosa	1.84 (0.92, 3.34)	.062
Binge Eating Disorder	1.88 (0.82, 3.75)	.100
Any behavior (≥ weekly) without self-reported ED diagnosis	1.63 (1.35, 1.96)	<.001

Note: Multivariate regression models included the following variables: age (numeric), race (categorical), Hispanic ethnicity (binary), enrollment status (binary), gender identity (categorical), residence (on-campus dorm, on-campus housing/apartment, fraternity/sorority, off-campus housing, off-campus with family), and athlete status.

In models evaluating associations with self-reported ED diagnoses, only AN was associated with increased odds of having adopted a vegan/vegetarian diet (OR = 1.92, 95% CI: 1.18, 2.98). While point estimates for BN and BED suggested increased risk, these associations were not statistically significant. In addition, individuals who reported weekly DEBs but did not have an ED diagnosis (the potentially undiagnosed cases) were more likely to report that they newly became vegan/vegetarian (OR = 1.63, 95% CI: 1.35, 1.96).

Across all models, women and gender minority students had consistently greater odds of having adopted a vegan/vegetarian diet compared to men, as did those living in independent housing (on- or off-campus suites/apartments) compared to on-campus dorms or living off-campus with family members. For example, in the model for positive SCOFF screens, the ORs associated with women and gender minority participants were 2.13 (95% CI: 1.70, 2.70) and 2.63 (95% CI: 1.40, 4.59), respectively, compared to men (Supplementary Table 1). In that same model, ORs associated with residence indicated participants living in on-campus suites and off-campus apartments had 1.72-times (95% CI: 1.23, 2.36) and 1.44-times (95% CI: 1.14, 1.81) higher odds of having adopted a vegan/vegetarian diet, respectively. Living in a fraternity or sorority was associated with decreased odds of having switched to veganism/vegetarianism (OR: 0.29, 95% CI: 0.07, 0.76).

Of the 11,503 participants in our sample, 11,357 had Weight Concern Scale data. Women who became vegan/vegetarian tended to have higher WCS scores (greater weight concern) than other groups (Figure 1). Vegetarian men expressed greater weight concern than non-vegetarian men, but their scores were comparable to non-vegetarian women.

Figure 1.

Distribution of Weight Concern Scale scores, by vegetarian status and across gender identities (n=11,357).

Groupings with the same superscript do not have statistically significant differences, where groups marked with different superscripts indicate a difference between groups. Non-vegetarian women had higher Weight Concern Scale scores than non-vegetarian men and non-vegetarian gender minority participants. Vegetarian men had higher scores than non-vegetarian men but had lower scores than vegetarian women.

3.2. Assessing Associations Between Adopting Vegan/Vegetarian Diet and Knowledge of ED Symptoms and Treatment-Seeking Experiences

Based on the administration of HMS, a subset of 2,567 participants (22.3%) of the study sample completed additional questions pertaining to knowledge of ED symptoms. Most students were able to accurately identify ED symptoms (>75% of students in both groups correctly categorized ED symptoms as such without incorrectly flagging unrelated or distractor answers as ED symptoms; see Table 5). Response patterns between groups suggested that participants who became vegan/vegetarian during college did not have less knowledge of ED symptoms, and there were no statistically significant differences observed.

Table 5.

Recognition of DEBs and help-seeking behaviors among those engaging in DEBs weekly or more often, stratified by vegan/vegetarian status.

	Overall	Became vegan/vegetarian	Did not become vegan/vegetarian	χ2 (df)	p-value
	n = 2,567	n = 146	n = 2,421
Symptom
knowledge
Weight loss				.87 (1)	.351
Yes	2,364 (92.1)	131 (89.7)	2,233 (92.2)
No	203 (7.9)	15 (10.3)	188 (7.8)
Restriction				3.54 (1)	.060
Yes	2,366 (92.2)	141 (96.6)	2,225 (91.9)
No	201 (7.8)	5 (3.4)	196 (8.1)
Purging				1.75 (1)	.185
Yes	2,448 (95.4)	143 (97.9)	2,305 (95.2)
No	119 (4.6)	3 (2.1)	116 (4.8)
Binge eating				3.64 (1)	.056
Yes	2,364 (92.1)	141 (96.6)	2,223 (91.8)
No	203 (7.9)	5 (3.4)	198 (8.2)
Wrong answer				.29 (1)	.590
Yes	619 (24.1)	32 (21.9)	587 (24.2)
No	1,948 (75.9)	114 (78.1)	1,834 (75.8)

Note: “Wrong answer” responses include participants who indicated weight loss, restriction, purging, or binge eating were not DEBs as well as those who incorrectly selected the distractor answer (rapid speech) as an example of an ED symptom.

Among the 2,850 participants without a self-reported ED diagnosis but who reported engaging in DEBs at least weekly (i.e., potentially undiagnosed cases, constituting 24.8% of the sample), most did not perceive need for mental health support or counseling. Approximately 58% of these participants reported disagreeing with the need for help, while 19% were uncertain. There was no significant difference in responses based on whether participants adopted vegan/vegetarian eating patterns (Table 6). Among participants who reported frequent ED behaviors, over two-thirds reported no past or current experiences engaging in counseling. However, most students (79%) agreed with the statement that they would know where to seek services on campus if needed.

Table 6.

Perceived need for help and help-seeking behaviors among participants engaging in DEBs weekly or more often (n (%)).

	Overall	Became vegan/vegetarian	Did not become vegan/vegetarian	χ2 (df)	p-value
	n = 2,850	n = 189 (6.6%)	n = 2,661 (93.4%)
Current perceived need for help				2.91 (2)	.233
Yes	647 (22.7)	52 (27.5)	595 (22.4)
No	1,665 (58.4)	106 (56.1)	1559 (58.6)
Uncertain	538 (18.9)	31 (16.4)	507 (19.1)
Experience with therapy/counseling				5.26 (2)	.065
None	1,962 (68.8)	128 (67.7)	1,834 (68.9)
Only prior	259 (9.1)	10 (5.3)	249 (9.4)
Since starting	629 (22.1)	51 (27.0)	578 (21.7)
Knows where to seek on-campus support				1.88 (1)	.171
Yes	2,240 (78.6)	157 (83.1)	2,083 (78.3)
No	600 (21.1)	32 (16.9)	568 (21.3)

4. Discussion

In this large national sample, approximately 5% of young adult students adopted a vegan/vegetarian eating pattern since starting college. In multivariate models, greater odds of adopting a vegan/vegetarian diet were found among participants with a positive SCOFF screen (OR = 1.79, (1.48, 2.16)) and a self-reported diagnosis of AN (OR = 1.92 (1.18, 2.98)), which supports the general association suggested in previous studies between eating pathology and vegan/vegetarian diets. The present analysis adds to and expands upon this first association by identifying relationships between becoming vegan/vegetarian during the college experience and (1) specific DEBs and newly becoming vegan/vegetarian, (2) experiencing weekly ED behaviors in the absence of an ED diagnoses, and (3) potential implications regarding health literacy and treatment-seeking experiences of college students. Across models, associations were stronger among women and gender minorities. This specific analysis focused on emerging and young adults in college and university settings and newly identifies residence as a significant covariate in its analytic models, helping identify an additionally vulnerable subgroup of the population where screening and supportive efforts may be beneficial.

All individual DEBS, when occurring at least weekly, were associated with having newly become vegan/vegetarian; this included binge eating behaviors (when coexisting with other DEBs but also as a sole DEB) and was not limited to calorie-restricting or calorie-purging behaviors. A dose-response relationship was observed such that more frequent DEB patterns were more strongly associated with having adopted a vegan/vegetarian diet. The proportion of individuals who reported disordered eating behaviors but also reported not having an ED diagnosis (i.e., potentially undiagnosed cases) was also higher among students who newly became vegan/vegetarian since matriculation. While point estimates for self-reported BED and BN were elevated, they did not reach statistical significance. However, the smaller number of diagnosed cases likely limited statistical power to detect relationships in these two specific subgroups. A post-hoc power analysis showed that with the exception of these two analytic subgroups, all other analyses were robust with statistical power well above 80%..

In this analysis, weight concern scale scores were higher among those who newly adopted vegan/vegetarian diet patterns compared to other college students. Even while deciding to become vegan/vegetarian can be driven by multiple factors, this data suggest weight concern is present for many in this sample who adopted this change in eating habits. College students may be particularly vulnerable to unsafe weight control practices and DEB risk in the absence of access to education or nutrition counseling about how to safely change their eating habits, nourish themselves, and ensure nutritional adequacy. An important implication for interventions may be parsing motivations, supporting healing around body image/weight concern and DEB while helping individuals continue to live in alignment with their values, such as continuing a vegetarian or vegan diet pattern while avoiding disordered restriction or other DEB. Even within ED treatment teams, providers are increasingly recognizing the possibility of both vegetarian and vegan diets as nutritionally appropriate when carefully planned and implemented to include a nutritious variety of plant-based foods (Fuller 2022).

While associations between DEB and becoming vegan/vegetarian were found, there were not significant differences in measures of mental health literacy. Specifically, among those with ≥ weekly DEB, those in the vegan/vegetarian group were not more likely to be unfamiliar with ED symptoms nor were they less likely to know where to access on-campus help. While there weren’t differences between groups with respect to perceiving the need for help, it was nonetheless notable that most students with DEB reported not feeling they currently needed help despite the frequency of behaviors. This substantiates concerns that treatment services go underutilized, ED symptoms go undetected, and consequences to physical and mental health likely worsen.

These findings appear to support the possibility that vegetarian diets, as a socially acceptable means of dietary restriction, may be a mechanism used by college students with DEBs to restrict intake. The finding that vegan/vegetarian students were just as aware of symptoms of EDs as their peers perhaps suggests that vegan/vegetarian students might not be unaware of the presence of ED risk in themselves, if it exists. Schools may have opportunities for intervention and prevention efforts in recognizing that vegetarian students may also be experiencing ED symptoms, and women and gender-minority students may be at increased risk (Supplementary Table 1). The observation that students who experienced DEBs who also lived in on- or off-campus apartment-style housing were more likely to adopt this dietary change than their peers living in dorms, sororities/fraternities, or off-campus with family helps to identify vulnerable subpopulations in need of targeted resources. Providing opportunities for skills acquisition and building eating competence among students living off campus or preparing their own meals in suite-style on-campus residences is another potential pathway to increasing support. Access to health educators and nutrition professionals can help students acquire the skills necessary to achieve nutritional adequacy when adopting vegan/vegetarian diets.

The extent to which intervention efforts should focus on educational campaigns is less clear. In our sample, most students demonstrated some degree of objective knowledge about ED symptoms and stated they knew where to find on-campus help, suggesting the lack of awareness of ED symptoms may not be a key barrier. However, a finding of particular concern is that most students who reported experiencing ED symptoms at least weekly also reported that they did not perceive the need for mental health support; other obstacles to help-seeking may be getting in the way, including shame, stigma, and low awareness of the consequences of untreated EDs. It is possible that targeting education to discourage normalizing ED symptoms may be more impactful for college students. Individuals with EDs can mistakenly perceive they are not sick enough or thin enough to require treatment (Eiring, 2021) or that DEBs are not problematic as they are often simply perceived as healthy eating tactics (Brytek-Matera, 2020). Education on the mental, physical, and social consequences of EDs may improve understanding and drive proactive help-seeking.

With BED being a relatively new albeit much more common diagnosis, and education and awareness lagging behind the traditional focus on AN and BN, recognition of BED presentations and visibility of treatment resources require amplification. The relationship between binge eating and adopting a vegan/vegetarian eating pattern is poorly understood, and there is a need to more fully understand the motivating and sustaining factors experienced by students with binge behaviors. It may also be relevant to investigate whether binge episodes include animal-based products among those who become vegan/vegetarian. Dietary restriction can accompany binge behaviors (preceding binges or serving as compensation) and it is not known how motivations such as weight-control and caloric restriction versus other factors (i.e., ethical concerns) are at play (Bray, 2023).

It is also important to recognize that students may have a variety of reasons for electing to follow a vegan or vegetarian diet apart from weight and body concerns. Not everyone who adopted a vegan/vegetarian eating pattern in our sample displayed DEBs or weight concerns. However, previous research has identified this dietary change occurring in college as more strongly associated with ED behaviors compared to adopting a vegan/vegetarian diet before college (Zickgraf, 2020). College can be a vulnerable time for young adults because of the transition into more independent lifestyles and also for the development of EDs (Maillet, 2024; Mathieu, 2023). A goal for education and interventions should be providing appropriate support for healing weight- and body-distress as it relates to eating pathology, while not minimizing or pathologizing health concern and moral/ethical values as potential drivers. An important area of future research is ascertaining how to support young adults’ exploration of vegetarian diets in safe and informed ways. It is imperative to support students to acquire agency and competency around self-nourishing and choosing lifestyle patterns that align with their values. Research supports adopting more plant-based eating patterns for both personal and planetary health, so education, systems, and resources are necessary to help this happen safely without exacerbating or introducing disordered cognitions and behaviors.

4.1. Limitations

Among the strengths of the study are its large sample size, national representation, and use of validated measures of disordered eating and weight-concern attitudes that have been lacking in prior studies on this topic. Reliance on self-reported data concerning the presence of DEBs and ED diagnoses is a limitation. The modest response rate to the HMS online surveys (e.g., between 13% in 2020 and 27% in 2017), while typical for online surveys, may introduce concerns about response bias. Further, the modular structure of the survey limited response rates to some of the questions included in our secondary analyses (i.e., knowledge of ED symptoms and campus supports), which may mean that those analyses were insufficiently powered to detect meaningful differences. The phrasing of some of the survey questions also needs to be considered. First, the survey did not separately evaluate vegan and vegetarian eating patterns and instead collected this information in one question. This precludes our ability to split them apart in our analysis. Second, “fasting for at least 8 hours” won’t capture student experiences across all disordered or unhealthy forms of restriction, although this question may be less vulnerable to misclassifying normative meat-avoidance behaviors among vegan/vegetarian students as disordered. Although patterns observed in the data may suggest EDs are present but not diagnosed, the HMS questions do not map directly to diagnostic criteria. Questions from the EDE-Q were incorporated into the HMS questionnaire because it was administered to a wide sample of participants, but a vegan/vegetarian-specific series of questions may be more precise in distinguishing disordered from nonpathological eating patterns (McLean, 2022; McLean, 2024). Similarly, the assessment of “perceived need for mental health treatment and support” is not limited to or specific to ED treatment. Finally, the questionnaires for the survey years included in the present analysis did not explore participants’ motivations for adopting a vegan/vegetarian diet; additional research with respect to differences in motivation is warranted.

Cross-sectional studies cannot establish causality or directionality of the association. While the HMS survey did include questions about vegetarian dietary status in other modules, potentially allowing for comparing DEB among those who were previously vegetarian with those who changed their eating pattern in college, the number of responses for individuals completing both modules was too small to sufficiently power an analysis comparable to the one put forth here. Additional research is needed to determine whether eating and weight concerns precede the adoption of the vegan/vegetarian diets, or vice versa. While past studies have consistently validated the existence of a relationship between eating pathology and vegan/vegetarian diets, longitudinal research informing the temporal order of the relationship between the adoption of these diets and DEBs is needed (Zuromski, 2015).

5. Conclusions

College is a vulnerable time of transition in ways that affect the health and behavioral patterns of young adults. We found that the new adoption of a vegan or vegetarian eating pattern during college was associated with eating pathology (SCOFF scores), as well as individual behaviors including fasting, calorie-purging mechanisms, and binge eating. Newly becoming vegan/vegetarian was also associated with DEB in the absence of an ED diagnosis, but there were not differences found regarding awareness of ED symptoms or on-campus support. Longitudinal research is needed to better understand the temporal relationship. In the meantime, there is sufficient cross-sectional evidence that ED prevention efforts, eating competence skill-building, and access to nutrition professionals to guide dietary behavior change are warranted in the college setting to best support student well-being.

Highlights.

• Among 11,503 college students, 4.6% reported adopting a vegan/vegetarian diet.

• Adopting a vegan/vegetarian diet was associated with positive SCOFF screens.

• Disordered eating behaviors were reported far more often than eating disorders.

• Binge eating was more prevalent among students adopting vegan/vegetarian diets.

• Students experiencing disordered eating did not perceive a need for help.

Abbreviations:

AN

Anorexia nervosa

ANOVA

analysis of variance

BED

Binge eating disorder

BN

Bulimia nervosa

DEB

disordered eating behaviors

ED

eating disorder

EDE-Q

Eating Disorder Examination Questionnaire

HMS

Healthy Minds Study

WCS

Weight Concern Scale