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Public Health Nutrition: 25(5), 1310–1320 doi:10.1017/S136898002100197X Pattern analysis of vegan eating reveals healthy and unhealthy patterns within the vegan diet Catherine T Gallagher, Paul Hanley and Katie E Lane* Research Institute for Sport and Exercise Sciences, I. M. Marsh Campus, Liverpool John Moores University, Barkhill Road, Aigburth, Liverpool L17 6BD, UK Submitted 7 September 2020: Final revision received 1 April 2021: Accepted 5 May 2021: First published online 11 May 2021 Abstract Objective: This study aimed to identify the types of foods that constitute a vegan diet and establish patterns within the diet. Dietary pattern analysis, a key instru- mentforexploringthecorrelationbetweenhealthanddisease,wasusedtoidentify patterns within the vegan diet. Design: A modified version of the EPIC-Norfolk FFQ was created and validated to include vegan foods and launched on social media. Setting: UK participants, recruited online. Participants:Aconveniencesampleof129vegansvoluntarilycompletedtheFFQ. Collected data were converted to reflect weekly consumptionto enable factor and cluster analyses. Results: Factor analysis identified four distinct dietary patterns including: (1) con- venience (22%); (2) health conscious (12%); (3) unhealthy (9%) and (4) tradi- tional vegan (7%). Whilst two healthy patterns were defined, the convenience patternwasthemostidentifiablepatternwithaprominenceofveganconvenience mealsandsnacks,vegansweetsanddesserts,sauces,condimentsandfats.Cluster analysis identified three clusters, cluster 1 ‘convenience’ (26·8%), cluster 2 ‘tradi- tional’ (22 %)andcluster3‘healthconscious’(51·2%).Clusters1and2consistedof Keywords an array of ultraprocessed vegan food items. Together, both clusters represent Dietary pattern analysis almost half of the participants and yielding similar results to the predominant Vegan diet dietary pattern, strengthens the factor analysis. Convenience Conclusions:Thesenovelresultshighlighttheneedforfurtherdietarypatternstud- Traditional ies with full nutrition and blood metabolite analysis in larger samples of vegans to Healthy enhance and ratify these results. Ultraprocessed foods Over half a million people in the UK (≈1% of the popula- Fe, Ca, iodine, n-3, Se and Zn in poorly adapted or non- (9) tion) follow a vegan diet where all animal sources are sub- fortified vegan diets . In dietary terms, a traditional vegan stituted withplant-basedalternatives.Veganismquadrupled diet refers to a diet that omits all products derived wholly (1) between 2014 and 2019 in the UK with 600 000 vegans orpartlyfromanimalorigin.Thedietfocusesmoreonwhole- (2,3) (10) reportedin2019 , whilethepopularityinvegandietscon- grains, pulses, fruit and vegetables . It remains unclear if (4) tinuestogrowworldwide .Thefoodindustryisresponding modern vegan dietary adaptation methods can deliver the to this by producing more processed vegan food and drink samehealthadvantagesastraditionalvegandiets.Forexam- (2,5) products than ever before . In January 2021, ‘Veganuary’ ple, if vegans are choosing ultraprocessed vegan products saw over 440 000 people in the UK committing to a vegan over more natural plant-based alternative sources, could (6) (11) diet , raising the profile of plant-based eating which has this compromise the overall quality of the vegan diet? . (7) been associated with a range of health benefits . Bywayofdefinition, ultraprocessed foods refer to products It is reported that a well-planned vegan diet can meet all mostly or entirely formulated from substances derived (8) (12) the nutritional requirements necessary for health .Thereis from foods that typically contain little or no whole foods . still some debate, however, about the nutritional quality of These products are usually high in saturated fat, sugar and vegan diets and the risk of nutritional deficiencies, notably salt. The majority of these food items are also considered (13,14) some key micronutrients such as vitamin B ,vitaminD, poor sources of protein, fibre and micronutrients . 12 *Corresponding author: Email k.e.lane@ljmu.ac.uk ©TheAuthor(s),2021.PublishedbyCambridgeUniversityPressonbehalfofTheNutritionSociety.ThisisanOpenAccessarticle,distributedunder the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distri- bution, and reproduction in any medium, provided the original work is properly cited. https://doi.org/10.1017/S136898002100197X Published online by Cambridge University Press Pattern analysis of vegan eating study 1311 (30) Studies over the past two decades have provided important Adaptation followed methods used by Dyett et al. in their information on the diet quality of various types of vegetar- evaluation of a validated FFQ for self-defined vegans in the ians, but no single study has addressed the quality of specific USA.VeganfooditemsavailableintheUKwereidentified vegan diets. Orlich et al.(7) reveal Adventist vegans con- from mainstream UK supermarkets and vegan UK forums. sumedthelowestamountsoffoodsandsnackshighinadded A collection of naturally vegan food products and newly sugars and saturated fats, in comparison with non-vegetar- emerging ultraprocessed vegan products were included in iansandothervegetariangroups.Thisargumentisconsistent the FFQ. Ten vegan volunteers in a UK university who met with much of the literature surrounding vegan diets(15−18) the study criteria took part in an initial pilot study. . However, the main weakness with this research is that it is Feedback from the volunteers was taken on board to further outdated and perhaps not considering the increasing variety modify the vegan FFQ. To further enhance validation of the of processed food and drinks that are now available to vegan-adapted FFQ, a focus group of Health and Care vegans. In 2018, the UK developed more vegan products Professions Council registered dietitians in the UK were then (5) consulted. Modifications and additions to the food groups thananyothernation .PopularUKsupermarketsarereact- ing by producing vegan wines with a pledge to ensure their were made accordingly based on the dietitians comments (19) to generate the finalised version of the vegan-adapted FFQ full range is suitable for vegans in the coming years .In (20) (see online supplemental material S1). Questionnaire instruc- 2019, Galaxy launched a vegan Mars bar in the UK , (21) tions stated that the FFQ must reflect dietary habits over the and in 2020, Mc Donald’s launched its first vegan meal . Thus, the production of vegan alternatives including vegan past month, and therefore, participants must have been fol- snacks and fast foods is prevalent and represents one of the lowing a vegan diet for at least 1 month. Further questions mainproductdevelopmenttrendswithinthefoodandretail were included such as motivations for adopting vegan life- industry. However,manyofthesefooditemscanbehighin style, age, length of time vegan, cooking skills and supple- saturated fats and sugars and if eaten regularly may pose a ment use to ensure evaluation of factors influencing diet (31) risk to health. Therefore, a review of current vegan dietary choice and nutritional knowledge . patterns is urgently required to address these uncertainties. Several studies have evaluated the dietary patterns of Recruitment omnivores, pesco, lacto, ovo and semi-vegetarians in com- Online social media accounts (Instagram and Facebook) (22−26) parisonwithvegandiets , but nonetodatehassubjected wereusedtorecruitsubjects.TheFFQwaslaunchedonsocial vegandietstodietarypatternanalysis.Itis important toestab- media accounts in the UK. The recruitment team asked for lish whether the increased availability of processed vegan vegans in the UK to complete and share the FFQ. In order replacementsforanimal-basedproductsisleadingtohabitual toreducebias,participants’involvementinthisstudywasvol- consumption of an array of ultraprocessed foods. The meth- untary. Participants gave informed consent prior to complet- odology for this unique study includes an innovative dietary ing the voluntary FFQ. Inclusion criteria required participants pattern analysis of vegan diets. Dietary pattern analysis offers to be living in the UK and aged over 18 years, so only adults aneffective way of understanding the diverse eating patterns could take part. Participants were also required to have fol- within vegan diets by evaluating methods of adaptation and lowedavegandietforatleast1month.Thisallowedspecific substitution(27). It was hypothesised that some vegan diets dietary patterns to be captured. wouldincorporate a range of food groups representing a tra- ditional well-planned vegan diet. This was expected to be the Statistical analysis most common dietary pattern. The vegan food industry has evolved; therefore, it was predicted that a convenience style Statistical analyses were performed using IBM SPSS(version eating pattern could also emerge, representing a small pro- 26.0; SPSS Inc.) and Microsoft Excel 2013. Data screening portion of the participants. and cleaning was conducted to check for any outliers and This study aimed to identify patterns within the vegan errors on the categorical and continuous variables. diet by establishing the everyday foods that vegans are Descriptive statistics such as frequencies and percentages choosing to consume enabling an evidence-based evalu- were calculated for characterisation of the participants (i.e. ation of the vegan diet. gender,agegroupsandlengthoftimevegan).Statisticaltests were used to calculate the significance of error. Methods Data screening SelectedfrequencyofconsumptionforeachfoodintheFFQ FFQ wascodedtoreflecthowofteneachitemwasconsumedper AFFQwascreatedusingLJMU-approvedOnlinesurveytool, weekfordietarypatternanalysisasfollowed:NEVERorless anonline food questionnaire creator, to enable the provision than once/month 0, 1–3/month, once a week, 2–4/week, of a validated interactive dietary assessment tool(28). The vali- 5–6/week, once a day, 2–3/d, 4–5/d, 6þ/d. This design datedEPIC-NorfolkFFQ(29)wasmodifiedtoincludequestions was taken from the validated EPIC-Norfolk FFQ, which (32,33) representative of foods and drinks suitable for vegans. hasalsobeenusedinotherstudies . Twomethodswere https://doi.org/10.1017/S136898002100197X Published online by Cambridge University Press 1312 CT Gallagher et al. Table 1 Food groups and food items included in the analysis of the FFQ cohort Food groups 1 Food groups 2 (variables) Definition and content 1. Legumes & nuts 1. Protein alternatives to meat & Soya, Tempeh, Tofu, silken tofu, lentils, pulses, nuts, falafel 2. Meat alternatives fish 3. Meat-free processed alternatives 2. Processed meat alternatives Vegan nuggets, burgers, bacon, sausage, no fish fingers, ham 4. Fish alternatives slices, turkey slices, chicken slices, meat-free mince, vegan chorizo 5. Vegan sandwiches 3. Convenience meals & snacks Garlic bread, pizza, sausage rolls, chips, ready prepared mash, 6. Vegan wraps selection of pre-made vegan sandwiches & wraps, ready 7. Ready-prepared foods meals, Not-zarrella sticks, French fries 8. Fresh fruit 4. Fruit Apples, pears, oranges, grapefruit, bananas, grapes, melon, 9. Tinned fruit peaches, strawberries, avocado, tinned fruit, dried fruit 10. Dried fruit 11. Vegetables 5. Vegetables Carrots, spinach, broccoli, Brussel sprouts, cabbage, peas, 12. Soup green beans, courgettes, cauliflower, parsnips, leeks, onions, garlic, mushrooms, sweet peppers, beansprouts, green salad, mixed vegetables, watercress, tomatoes, sweetcorn, beet- root, coleslaw, vegetable soup, rainbow rice 13. Starchy carbohydrates 6. Refined grains White bread, scones, crackers, pitta, sugary cereal, plain cer- eal, white rice, pasta, tinned pasta, noodles, lasagne, cereals (except high fibre options) 14. High-fibre carbohydrates 7. Wholegrains Brown bread, wholemeal bread, porridge, all bran, wholegrain cereals, brown rice, wholemeal pasta, wild rice 15. White potatoes 8. Potatoes Boiled potatoes, roast potatoes, sweet potatoes, home-made 16. Sweet potatoes mash, baked potatoes, baby potatoes 17. Plant-based milks 9. Dairy alternatives Oat milk, soya milk, almond milk, rice milk, hazelnut milk, coco- 18. Vegan cheese nut milk hemp, pea milk, Nutritional yeast, vegan hard 19. Vegan yoghurts cheese, Yoghurt alternatives, 20. Fats and oils 10. Fats and oils Vegan butter spreads, pesto, peanut butter, olive oil, sunflower oil, coconut oil, avocado oil, canola oil, sunflower ghee, rape- seed oil, fry light 21. Cakes & biscuits 11. Vegan cakes & biscuits Cookies, Digestive twists, bourbons, Lotus Biscoff, vegan sponge cake, vegan cereal bars, party ring minis, granola bars 22. Sweets and desserts 12. Vegan sweets & desserts Fudge, cheesecake pots, chocolate mousse pots, dark choco- late, non-dairy ice cream, churros, star burst sweets 23. Vegan crisps 13. Vegan crisps Lentil Chips, Kettle chips, walkers, tortilla chips, vegetable chips, pretzel bites 24. Sauces & condiments 14. Sauces and condiments BBQsauce,cheesesauce, Red lasagne sauce, free from sauce, olive oil, vegetable oils, seeds, tahini, vegetable pates, mayonnaise, hummus, chocolate spread, coleslaw, potato salad 25. Salt 15. Salt All added salts 26. Alcohol 16. Alcohol Vegan friendly alcohols 27. Vegan takeaway 17. Vegan takeaway From fast-food outlets providing vegan options 28. Cooking 18. Cooking from scratch Additional question to help with establishing vegan patterns 29. Recipes used 19. Creating own recipes Additional question to help with establishing vegan patterns 30. Use of vegan brands 20. Purchasing vegan brands Additional question to help with establishing vegan patterns used to classify the individual food items before applying used factor analysis as a statistical method to reduce large factor and cluster analyses. In the first instance, the food sets of dietary intake variables into smaller sets of variables (36,37) and drink items were combined and collapsed into thirty that represent eating patterns . The smaller sets of food groups and in the second twenty food groups composite variables derived through the principal compo- (Table 1), respectively, with similar nutrient profiles, simi- nent method are referred to as ‘components’, and the (34) larly to previous research by Ashby-Mitchell et al. . variables within these are referred to as ‘factors’.The Kaiser–Mayer–OlkinmeasureandBartlett’stestofsphericity were undertaken before applying the principal component Factor analysis method, to ensure the data were suitable for factor analy- Factor analysis with the principal component method was (38) sis . The twenty foodvariables fromfoodgroups2shown performed in SPSS, with the procedure ‘dimension reduc- inTable 1wereenteredintothefactoranalysis.Obliminand tion’ and ‘FACTOR’ on both sets of food groups to identify Varimax rotations were applied. The components derived the primary components, which accounted for variation in from the Oblimin rotation were selected similar to previous dietary intake. However, the smaller set of food groups (39,40) work by researchers exploring dietary patterns .The (n20)wasdeemedmoreappropriateduetothesmallsam- rotation redistributes the variance of each component (35) (41) plesize . Themethodsfollowedpreviousstudiesthathave allowing for a simpler structure . Oblimin rotation was https://doi.org/10.1017/S136898002100197X Published online by Cambridge University Press Pattern analysis of vegan eating study 1313 Fig. 1 Scree plot to show eigenvalues of each component number chosenasthepreferredmethodof‘rotation’asithasarange Most participants were female (87%), and most were (42) of advantages compared with other types of rotation . aged18–24(36%)years.Themostcommonreasonselected The number of components selected was based on the for following a vegan lifestyle was ‘Health, Environment & assessmentofthescreeplot,withvalues>1deemedappro- Animalwelfare’(43%).Healthbenefitswereintheminority priate to establish the patterns that explain the largest with only 3% following the vegan lifestyle primarily for (36) proportion of variance . Six components had an eigen- ‘health’. It is important to note that on the questionnaire, value>1,buttherewasagradualbreakinthescreeplotafter these were presented as separate reasons and not a single the fourth component (Fig. 1); therefore, four components reason. Participants were able to select more than one rea- were retained. The dietary patterns were characterised by son.Mostvegans(41%)hadbeenfollowingavegandietfor highandlowintakesofveganfoodanddrinks.Thepatterns 1–3years.Someparticipants(17%)wereeatingavegandiet werelabelledbasedonthetypesoffactorsrepresentingthe for <6 months; (8%) 6–12 months; (23%) 4–10 years and component and explanations in the literature. (11%) over 10 years. From those taking nutritional supple- ments,themajoritytookvitaminB (68%).Almosthalftook 12 Cluster analysis vitaminD(42%).Amoderatenumber(26%)weretakingFe Two-factor cluster analysis identifies groupings by running supplements and 19% took Ca supplements. A small num- pre-clustering first and then by running hierarchical methods berofparticipants(15%,12%,14%and7%)consumedZn, (35) to enable automatic selection of the number of clusters . iodine, n-3 and Se supplements, respectively. Again these Two-factor cluster analysis was performed to order the twenty micronutrientswerepresentedinalistonthequestionnaire, food groups in a dendrogram, where food groups with the and participants were able to select more than one highest correlations were further grouped together, while supplement. samples with small correlations were widely separated. In particular,thetwofoodgroupswiththelargestcorrelationwere identified and merged into a single ‘synthetic’ sample. The Factor analysis remaining food groups were then searched for the largest Inspection of the correlation matrix revealed the presence of correlation with the synthetic sample. This process was manycoefficients of 0·3 and above. The Kaiser–Meyer–Olkin (38) repeated until all samples were merged into a single sample, value was 0·727, reaching the recommended value of 0·5 (44) and the correlations among samples were then expressed as The Barlett’sTestofSphericity reached statistical signifi- (43) cance,supportingthefactorabilityofthecorrelationmatrix(35). a hierarchical tree . Thedietarypatternswerecharacterisedbyhighandlow Factor analysis with the principal component method intakes of vegan food and drinks. The clusters were revealed the presence of six components with eigenvalues labelledbasedonthetypesofinputsrepresentingthecom- exceeding1,explaining22%,12%,9%,7%,7%and5%of ponent and explanations in the literature. the variance. However, inspection of the scree plot (Fig. 1) revealed a gradual break after the fourth component. Therefore,thefirst fourcomponentsexplainthelargestpro- Results portion of variance in the dietary intake data and were retained as ‘dietary patterns’. Together these components Participant characteristics represent a cumulative percentage of 50% of the inter- Data collection took place from Monday 2 March 2020 individual variability. To aid the interpretation of these four throughFriday3April2020.Therewere129fullycompleted components, oblimin rotation was performed, representing FFQ. Sample characteristics are presented in Table 2. fourdefinite dietary patterns (Table 3). The first component https://doi.org/10.1017/S136898002100197X Published online by Cambridge University Press
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