“An Important Part of Who I am”: The Predictors of Dietary Adherence among Weight-Loss, Vegetarian, Vegan, Paleo, and Gluten-Free Dietary Groups
Abstract
:1. Introduction
1.1. Personality Characteristics Linked to Dietary Adherence
1.2. Mental Health and Its Link to Dietary Adherence
1.3. The Neglected Role of Motivational Factors in Adherence
1.4. The Current Study
- To compare the degree of adherence between dietary groups in order to establish whether people following some restrictive dietary patterns are more adherent than others.
- To investigate predictors of adherence across dietary groups to establish whether there are some psychosocial factors that may support adherence universally, regardless of which dietary pattern a person seeks to follow. We tentatively predicted that the importance of motivational factors may have been underestimated in prior work focusing on one dietary group at a time, relative to personality and mental health factors.
2. Materials and Methods
2.1. Participants and Design
2.2. Measures of Adherence
2.2.1. Adherence
2.3. Measure of Personality Characteristics
2.3.1. Self-Control
2.3.2. Emotional Eating
2.3.3. Big Five
2.4. Measures of Mental Health
2.4.1. Disordered Eating Behaviors
2.4.2. Depression, Anxiety, and Stress Symptoms
2.5. Measures of Motivational Factors
2.5.1. Dietary motivation
2.5.2. Moral Foundations
2.5.3. Social Identification with Dietary Group
2.5.4. Self-Efficacy
2.5.5. Demographics
2.6. Analysis Plan
2.6.1. Qualitative Analyses
2.6.2. Quantitative Analyses
3. Results
3.1. Qualitative Analyses
3.1.1. Vegans: Diet Adherence as a Socio-Political Struggle
“Realizing the fact that meat comes from animals who suffer in order to feed people. Same applies to dairy. The entire meat industry is evil and I have no intention to support it.”(P142)
“The ongoing desire to do no harm.”(P57)
3.1.2. Vegetarians: Diet Adherence as Standing up for one’s Moral and Ethical Values
“Reminding myself of the ethical reasons of why I am vegetarian definitely keeps me on track…Knowing that I am standing up for something that I believe in makes me feel proud.”(P26)
“My belief system is about viewing animals as companions/to be respected in their own right not consumed as food. It is an important part of who I am.”(P36)
“My environmental values. If I eat meat, it isn’t the same as it used to be. I feel very guilty and disgusted, and think about the animal alive and yada yada yada. So I avoid meat for the discomfort I experience now.”(P9)
3.1.3. Paleo: Diet Adherence as Personal Preference and Benefit
“Getting into a routine and feeling benefits i.e., more energy, weight loss, clearer skin etc.”(P184)
“I don’t need help. I no longer crave processed, scary foods.”(P187)
“I feel (and look) so much better when I stick to paleo eating that it’s my strongest motivation.”(P185)
3.1.4. Gluten Free: Diet Adherence as the only Viable Option
“I get violently ill when I eat gluten.”(P217)
“Gluten causes pain. I don’t like pain. I don’t eat gluten.”(P218)
“I vomit 3 h after ingesting gluten, so it’s not a hard decision to avoid it.”(P233)
3.1.5. Weight-Loss Diet: Adherence as Personal Goal of Self-Discipline
“Regularly maintenance and reassessing diet and dietary needs. Mindful action daily.”(P273)
“looking at myself in the mirror and also eating foods outside of my diet plan makes me feel horrible and guilty so that helps as well.”(P254)
“The fact that I’ve started and that I should stick to it.”(P247)
3.2. Quantitative Analyses
3.2.1. Personality Characteristics
3.2.2. Mental Health
3.2.3. Motivation
3.2.4. Final Predictive Model of Dietary Adherence
4. Discussion
4.1. Summary of the Findings
4.2. Implications
4.3. Limitations
5. Conclusions
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
- Popkin, B.M. Does global obesity represent a global public health challenge? Am. J. Clin. Nutr. 2011, 93, 232–233. [Google Scholar] [CrossRef] [PubMed]
- Serdula, M.K.; Mokdad, A.H.; Williamson, D.F.; Galuska, D.A.; Mendlein, J.M.; Heath, G.W. Prevalence of attempting weight loss and strategies for controlling weight. Jama 1999, 282, 1353–1358. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Ikeda, J.; Amy, N.K.; Ernsberger, P.; Gaesser, G.A.; Berg, F.M.; Clark, C.A.; Peters, P. The national weight control registry: A critique. J. Nut. Educ. Behav. 2005, 37, 203–205. [Google Scholar] [CrossRef]
- Lowe, M.R.; Timko, C.A. Dieting: Really harmful, merely ineffective or actually helpful? Br. J. Nutr. 2004, 92, S19–S22. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Neumark-Sztainer, D.; Wall, M.; Haines, J.; Story, M.; Eisenberg, M.E. Why Does Dieting Predict Weight Gain in Adolescents? Findings from Project EAT-II: A 5-Year Longitudinal Study. J. Am. Diet. Assoc. 2007, 107, 448–455. [Google Scholar] [CrossRef] [PubMed]
- Elfhag, K.; Rössner, S. Who succeeds in maintaining weight loss? A conceptual review of factors associated with weight loss maintenance and weight regain. Obes. Rev. 2005, 6, 67–85. [Google Scholar] [CrossRef]
- Kemp, E.; Bui, M.Y.; Grier, S. When food is more than nutrition: Understanding emotional eating and overconsumption. J. Consum. Behav. 2013, 12, 204–213. [Google Scholar] [CrossRef]
- Leehr, E.J.; Krohmer, K.; Schag, K.; Dresler, T.; Zipfel, S.; Giel, K.E. Emotion regulation model in binge eating disorder and obesity—A systematic review. Neurosci. Biobehav. Rev. 2015, 49, 125–134. [Google Scholar] [CrossRef]
- Canetti, L.; Berry, E.M.; Elizur, Y. Psychosocial predictors of weight loss and psychological adjustment following bariatric surgery and a weight-loss program: The mediating role of emotional eating. Int. J. Eat. Disord. 2009, 42, 109–117. [Google Scholar] [CrossRef]
- Wheeler, K.; Wagaman, A.; McCord, D. Personality Traits as Predictors of Adherence in Adolescents With Type I Diabetes. J. Child. Adolesc. Psychiatr. Nurs. 2012, 25, 66–74. [Google Scholar] [CrossRef]
- Edwards-George, J.B.; Leffler, D.A.; Dennis, M.D.; Franko, D.L.; Blom-Hoffman, J.; Kelly, C.P. Psychological correlates of gluten-free diet adherence in adults with celiac disease. J. Clin. Gastroenterol. 2009, 43, 301–306. [Google Scholar] [CrossRef] [PubMed]
- Brantley, P.J.; Stewart, D.W.; Myers, V.H.; Matthews-Ewald, M.R.; Ard, J.D.; Coughlin, J.W.; Stevens, V.J. Psychosocial predictors of weight regain in the weight loss maintenance trial. J. Behav. Med. 2014, 37, 1155–1168. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- McGuire, M.T.; Wing, R.R.; Klem, M.L.; Hill, J.O. What Predicts Weight Regain in a Group of Successful Weight Losers? J. Consult. Clin. Psychol. 1999, 67, 177–185. [Google Scholar] [CrossRef] [PubMed]
- Sainsbury, K.; Mullan, B.; Sharpe, L. Gluten free diet adherence in coeliac disease. The role of psychological symptoms in bridging the intention-behaviour gap. Appetite 2013, 61, 52–58. [Google Scholar] [CrossRef] [Green Version]
- Sainsbury, K.; Marques, M.M. The relationship between gluten free diet adherence and depressive symptoms in adults with coeliac disease: A systematic review with meta-analysis. Appetite 2018, 120, 578–588. [Google Scholar] [CrossRef] [Green Version]
- Presnell, K.; Stice, E.; Tristan, J. Experimental investigation of the effects of naturalistic dieting on bulimic symptoms: Moderating effects of depressive symptoms. Appetite 2008, 50, 91–101. [Google Scholar] [CrossRef]
- Wadden, T.A.; Butryn, M.L.; Byrne, K.J. Efficacy of Lifestyle Modification for Long-Term Weight Control. Obes. Res. 2004, 12, 151S–162S. [Google Scholar] [CrossRef]
- Haynes, A.; Kersbergen, I.; Sutin, A.; Daly, M.; Robinson, E. A systematic review of the relationship between weight status perceptions and weight loss attempts, strategies, behaviours and outcomes. Obes. Rev. 2018, 19, 347–363. [Google Scholar] [CrossRef]
- Puhl, R.M.; Heuer, C.A. Obesity stigma: Important considerations for public health. Am. J. Public Health 2010, 100, 1019–1028. [Google Scholar] [CrossRef]
- Rose, C.; Howard, R. Living with coeliac disease: A grounded theory study. J. Hum. Nutr. Diet. 2014, 27, 30–40. [Google Scholar] [CrossRef]
- Cherry, E. I Was a Teenage Vegan: Motivation and Maintenance of Lifestyle Movements. Sociol. Inq. 2015, 85, 55–74. [Google Scholar] [CrossRef]
- Fox, N.; Ward, K. Health ethics and environment: A qualitative study of vegetarian motivations. Appetite 2008, 50, 422–429. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Ruby, M.B. Vegetarianism. A blossoming field of study. Appetite 2012, 58, 141–150. [Google Scholar] [CrossRef] [PubMed]
- Rothgerber, H. A comparison of attitudes toward meat and animals among strict and semi-vegetarians. Appetite 2014, 72, 98–105. [Google Scholar] [CrossRef]
- Cruwys, T.; Platow, M.J.; Rieger, E.; Byrne, D.G.; Haslam, S.A. The social psychology of disordered eating: The Situated Identity Enactment model. J. Pers. Soc. Psychol. 2016, 27, 160–195. [Google Scholar] [CrossRef]
- Epiphaniou, E.; Ogden, J. Successful weight loss maintenance and a shift in identity: From restriction to a new liberated self. J. Health Psychol. 2010, 15, 887–896. [Google Scholar] [CrossRef]
- Rothgerber, H. Can you have your meat and eat it too? Conscientious omnivores, vegetarians, and adherence to diet. Appetite 2015, 84, 196–203. [Google Scholar] [CrossRef]
- Rothgerber, H. Underlying differences between conscientious omnivores and vegetarians in the evaluation of meat and animals. Appetite 2015, 87, 251–258. [Google Scholar] [CrossRef]
- Shimpo, M.; Fukkoshi, Y.; Akamatsu, R. Correlations between self-efficacy in resisting six temptations and dietary energy and macronutrient intake at each meal. Eat. Behav. 2014, 15, 563–566. [Google Scholar] [CrossRef]
- Warziski, M.T.; Sereika, S.M.; Styn, M.A.; Music, E.; Burke, L.E. Changes in self-efficacy and dietary adherence: The impact on weight loss in the PREFER study. J. Behav. Med. 2008, 31, 81–92. [Google Scholar] [CrossRef]
- Leffler, D.A.; Edwards George, J.B.; Dennis, M.; Cook, E.F.; Schuppan, D.; Kelly, C.P. A prospective comparative study of five measures of gluten-free diet adherence in adults with coeliac disease. Aliment. Pharmacol. Ther. 2007, 26, 1227–1235. [Google Scholar] [CrossRef] [PubMed]
- Louis, W.R.; Davies, S.; Smith, J.R.; Terry, D. Pizza and pop and the student identity: The role of referent group norms in healthy and unhealthy eating. J. Pers. Soc. Psychol. 2007, 147, 57–74. [Google Scholar] [CrossRef] [PubMed]
- Cade, J.E.; Burley, V.J.; Warm, D.L.; Thompson, R.L.; Margetts, B.M. Food-frequency questionnaires: A review of their design, validation and utilisation. Nutr. Res. Rev. 2004, 17, 5. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Cade, J.; Thompson, R.; Burley, V.; Warm, D. Development validation and utilisation of food-frequency questionnaires—A review. Public Health Nutr. 2002, 5, 567–587. [Google Scholar] [CrossRef] [Green Version]
- National Health and Medical Research Council (NHMRC). Australian Dietary Guidelines; National Health and Medical Research Council: Canberra, Australia, 2013. [CrossRef]
- Tangney, J.P.; Baumeister, R.F.; Boone, A.L. High Self-Control Predicts Good Adjustment, Less Pathology, Better Grades, and Interpersonal Success. J. Pers. 2004, 72, 271–324. [Google Scholar] [CrossRef]
- Wardle, J. Eating style: A validation study of the Dutch eating behaviour questionnaire in normal subjects and women with eating disorders. J. Psychosom. Res. 1987, 31, 161–169. [Google Scholar] [CrossRef]
- Donnellan, M.B.; Oswald, F.L.; Baird, B.M.; Lucas, R.E. The mini-IPIP scales: Tiny-yet-effective measures of the Big Five factors of personality. Psychol. Assess. 2006, 18, 192–203. [Google Scholar] [CrossRef]
- Goldberg, L.R. Personality Psychology in Europe. In A Broad-Bandwidth, Public-Domain, Personality Inventory Measuring the Lower-Level Facets of Several Five-Factor Models; Mervielde, I., Deary, F., Fruyt, D., Ostendorf, F., Eds.; Tilburg University Press: Tilburg, The Netherlands, 1999; pp. 7–28. [Google Scholar]
- Friborg, O.; Clausen, L.; Rosenvinge, J.H. A five-item screening version of the Eating Disorder Inventory (EDI-3). Compr. Psychiatry 2013, 54, 1222–1228. [Google Scholar] [CrossRef]
- Lovibond, P.F.; Lovibond, S.H. The structure of negative emotional states: Comparison of the Depression Anxiety Stress Scales (DASS) with the Beck Depression and Anxiety Inventories. Behav. Res. Ther. 1995, 33, 335–343. [Google Scholar] [CrossRef]
- Page, A.C.; Hooke, G.R.; Morrison, D.L. Psychometric properties of the Depression Anxiety Stress Scales (DASS) in depressed clinical samples. Br. J. Clin. Psychol. 2007, 46, 283–297. [Google Scholar] [CrossRef]
- Steptoe, A.; Pollard, T.M.; Wardle, J. Development of a Measure of the Motives Underlying the Selection of Food: The Food Choice Questionnaire. Appetite 1995, 25, 267–284. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Davies, C.L.; Sibley, C.G.; Liu, J.H. Confirmatory factor analysis of the moral foundations questionnaire independent scale validation in a new zealand sample. Soc. Psychol. 2014, 45, 431–436. [Google Scholar] [CrossRef]
- Graham, J.; Nosek, B.A.; Haidt, J.; Iyer, R.; Koleva, S.; Ditto, P.H. Mapping the moral domain. J. Pers. Soc. Psychol. 2011, 101, 366–385. [Google Scholar] [CrossRef] [PubMed]
- Graham, J.; Haidt, J.; Nosek, B.A. Liberals and Conservatives Rely on Different Sets of Moral Foundations. J. Pers. Soc. Psychol. 2009, 96, 1029–1046. [Google Scholar] [CrossRef] [PubMed]
- Leach, C.W.; van Zomeren, M.; Zebel, S.; Vliek, M.L.W.; Pennekamp, S.F.; Doosje, B.; Ouwerkerk, J.W. Group-level self-definition and self-investment: A hierarchical (multicomponent) model of in-group identification. J. Pers. Soc. Psychol. 2008, 95, 144–165. [Google Scholar] [CrossRef]
- Hoeppner, B.; Kelly, J.; Urbanoski, K.A.; Slymaker, V. Comparative utility of a sing-item vs. multiple-item measure of self-efficacy in predicting relapse among young adults. J. Subst. Abuse Treat. 2012, 41, 305–312. [Google Scholar] [CrossRef] [Green Version]
- Clarke, V.; Braun, V.; Hayfield, N. Using Thematic Analysis in Psychology. In Qualitative Psychology: A Practical Guide to Research Methods; Smith, J.A., Ed.; Sage: Southend Oaks, CA, USA, 2015. [Google Scholar]
- Elliott, R.; Fischer, C.T.; Rennie, D.L. Evolving guidelines for publication of qualitative research studies in psychology and related fields. Br. J. Clin. Psychol. 1999, 38, 215–229. [Google Scholar] [CrossRef] [Green Version]
- Braun, V.; Clarke, V. Using thematic analysis in psychology. Qual. Res. Psychol. 2006, 3, 77–101. [Google Scholar] [CrossRef] [Green Version]
- Boyatzis, R.E. Transforming Qualitative Information: Thematic Analysis and Code Development; Sage: New York, NY, USA, 1988. [Google Scholar]
- Norwood, R.; Cruwys, T.; Chachay, V.S.; Sheffield, J. The psychological characteristics of people consuming vegetarian, vegan, paleo, gluten free and weight loss dietary patterns. Obes. Sci. Pract. 2019, 5, 148–158. [Google Scholar] [CrossRef] [PubMed]
- Cruwys, T.; Platow, M.J.; Angullia, S.A.; Chang, J.M.; Diler, S.E.; Kirchner, J.L.; Wadley, A.L. Modeling of food intake is moderated by salient psychological group membership. Appetite 2012, 58, 754–757. [Google Scholar] [CrossRef]
- Putterman, E.; Linden, W. Appearance versus health: Does the reason for dieting affect dieting behaviour? J. Behav. Med. 2004, 27, 185–204. [Google Scholar] [CrossRef] [PubMed]
- Armstrong, M.J.; Mottershead, T.A.; Ronksley, P.E.; Sigal, R.J.; Campbell, T.S.; Hemmelgarn, B.R. Motivational interviewing to improve weight loss in overweight and/or obese patients: A systematic review and meta-analysis of randomized controlled trials. Obes. Rev. 2011, 12, 709–723. [Google Scholar] [CrossRef] [PubMed]
- Smith, D.E.; Heckemeyer, C.M.; Kratt, P.P.; Mason, D.A. Motivational interviewing to improve adherence to a behavioral weight-control program for older obese women with NIDDm: A pilot study. Diabetes Care 1997, 20, 53–54. [Google Scholar] [CrossRef]
- Addolorato, G.; De Lorenzi, G.; Abenavoli, L.; Leggio, L.; Capristo, E.; Gasbarrini, G. Psychological support counselling improves gluten-free diet compliance in coeliac patients with affective disorders. Aliment. Pharmacol. Ther. 2004, 20, 777–782. [Google Scholar] [CrossRef]
- Baker, R.C.; Kirschenbaum, D.S. Self-monitoring may be necessary for successful weight control. Behav Ther. 1993, 24, 377–394. [Google Scholar] [CrossRef]
- Hall, N.J.; Rubin, G.; Charnock, A. Systematic review: Adherence to a gluten-free diet in adult patients with coeliac disease. Aliment. Pharmacol. Ther. 2009, 30, 315–330. [Google Scholar] [CrossRef] [PubMed]
- Leffler, D.A.; Dennis, M.; Edwards George, J.B.; Jamma, S.; Magge, S.; Cook, E.F.; Kelly, C.P. A Simple Validated Gluten-Free Diet Adherence Survey for Adults With Celiac Disease. Clin. Gastroenterol. Hepatol. 2009, 7, 530–536. [Google Scholar] [CrossRef]
Theme Example | Vegetarian (n = 48) | Vegan (n = 128) | Paleo (n = 42) | Gluten Free (n = 38) | Weight Loss (n = 36) | Pearson χ (df) | p Value |
---|---|---|---|---|---|---|---|
Facilitators | |||||||
Ethical/moral | 46.7% a | 80.5% b | 12.8% c | 8.6% c | 42.9% a | 92.04 (4) | <0.001 |
“It’s SO easy to be vegan once you have made the ethical connection. Once you see animals as living being creatures who feel pain and joy. Animal products and by-products don’t look like food to me. Eating a steak would be as absurd as eating cardboard.” | |||||||
Health | 11.1% a | 34.1% b | 53.8% c | 68.6% c | 48.6% b, c | 33.64 (4) | <0.001 |
“I feel very unwell if I do not maintain my dietary pattern so a feeling of wellness after eating is what helps me to maintain my diet.” | |||||||
Weight loss | 2.2% a, b | 1.6% b | 12.8% a, c | 2.9% a, b | 22.9% c | 26.21 (4) | <0.001 |
“The thought of losing fat fast and being lean” | |||||||
Identity | 8.9% a, b | 9.8% a | 0.0% b | 0.0% a, b | 0.0% a, b | 11.06 (4) | 0.026 |
“I identify as Vegan above all other things so eating non-vegan food would be betraying myself.” | |||||||
Enjoyment | 17.8% a | 8.1% a, b | 17.9% a | 2.9% b | 2.9% b | 10.42 (4) | 0.034 |
“Coming to the realization that healthy foods are actually delicious and more satisfying than junk food and sweets.” | |||||||
Conscientiousness | 24.4% a | 8.1% b | 20.5% a | 20.0% a | 22.9% a | 10.35 (4) | 0.035 |
“Being prepared, reading absolutely every label (this happens in the shopping process so I don’t have Gluten products in the cupboard). Check everything I put into my mouth.” | |||||||
Barriers | |||||||
Lack of willpower | 26.7% a, b | 20.3% a | 41.0%b | 25.7% a, b | 68.6% c | 32.31 (4) | <0.001 |
“When I have cravings it can take mental strength.” | |||||||
Mood/emotion | 0.0% a | 8.1% b, c | 17.9% c, d | 2.9%a, b | 22.9% d | 17.47 (4) | 0.002 |
“Whenever I am feeling down/depressed as a result of other life stressors I have generally used food as a coping mechanism so it is hard to stay strict during these times” | |||||||
Inconvenience | 44.4% a | 39.8% a | 33.3% a | 48.6% a | 11.4% b | 13.52 (4) | 0.009 |
“Sometimes it is difficult when traveling and I have at certain times not followed my dietary patterns as a necessity.” | |||||||
None | 15.6% a, b | 25.2% a | 12.8% a, b | 14.3% a, b | 2.9% b | 11.11 (4) | 0.025 |
I never have struggled with it and I never will. |
β | SE | p Value | Semi-Partial r2 | F(df) | Model R2 | |
---|---|---|---|---|---|---|
Measured adherence | 38.67 (3,271) | 0.30 | ||||
Predictors | ||||||
Self-efficacy | 0.16 | 0.03 | 0.004 | 0.02 | ||
Social identification | 0.41 | 0.04 | <0.001 | 0.16 | ||
Weight control motivation | −0.18 | 0.03 | 0.001 | 0.03 | ||
Subjective adherence | 48.62 (3,270) | 0.35 | ||||
Predictors | ||||||
Self-efficacy | 0.41 | 0.02 | <0.001 | 0.15 | ||
Social identification | 0.33 | 0.04 | <0.001 | 0.10 | ||
Mood motivation | −0.11 | 0.03 | 0.027 | 0.01 |
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Cruwys, T.; Norwood, R.; Chachay, V.S.; Ntontis, E.; Sheffield, J. “An Important Part of Who I am”: The Predictors of Dietary Adherence among Weight-Loss, Vegetarian, Vegan, Paleo, and Gluten-Free Dietary Groups. Nutrients 2020, 12, 970. https://doi.org/10.3390/nu12040970
Cruwys T, Norwood R, Chachay VS, Ntontis E, Sheffield J. “An Important Part of Who I am”: The Predictors of Dietary Adherence among Weight-Loss, Vegetarian, Vegan, Paleo, and Gluten-Free Dietary Groups. Nutrients. 2020; 12(4):970. https://doi.org/10.3390/nu12040970
Chicago/Turabian StyleCruwys, Tegan, Rebecca Norwood, Veronique S. Chachay, Evangelos Ntontis, and Jeanie Sheffield. 2020. "“An Important Part of Who I am”: The Predictors of Dietary Adherence among Weight-Loss, Vegetarian, Vegan, Paleo, and Gluten-Free Dietary Groups" Nutrients 12, no. 4: 970. https://doi.org/10.3390/nu12040970