Introduction
According to the DSM-5, binge eating disorder is characterized by the intake of large amounts of food in a discrete period, with a sense of lack of control. Although the main cause of this disorder is not yet well known, many factors, such as early life experiences [1, 2,  3, 4], psychological factors of shame [2, 3, 5, 6], and self-criticism [6, 7] are involved. However, the mediating role of shame and self-criticism has not yet been investigated. A review of previous research shows that negative childhood experiences related to body image and weight are associated with eating problems and binge eating symptoms. On the other hand, shame and self-criticism as mediators predict directly or indirectly eating problems and binge eating symptoms. Binge eating symptoms are so prevalent and many people struggle with them without being diagnosed [8]. In Iran, many people suffer from the symptoms of eating disorders, especially overeating [9]. Despite the progress of increasing research on binge eating, the  underlying factors of these behaviors to better understand and solve this problematic behavior have not been identified.
Methods
Structural equation modeling was employed in this study. Given that a sample size greater than 200 is recommended for modeling good structural equations, 283 participants were selected using multistage cluster random sampling from all undergraduate and graduate students of Shahid Beheshti University of Medical Sciences in Tehran. The anonymity of participants was granted and oral consent was received.
Research Tools
Body Image Victimization Experiences Scale (BIVES): This scale was developed in 2016 by Duarte and Pinto-Gouveia [10] and measures childhood or adolescence experiences of bullying and teasing related to physical appearance. 
Body Image Shame Scale (BISS): This scale was designed in 2015 [11] and is a 14-item scale assessing body image shame. 
Forms of Self-Criticizing/Self-Reassuring Scale (FSCRS): This scale was created by Gilbert and Clarke [12]. The FSCRS is a 22-item self-report instrument and assesses how respondents typically think and react when they face setbacks or failures. 
Binge Eating Scale (BES): This scale was designed by Gormally et al. [13]. BES is a 16-item self-report instrument assessing behavioral, emotional, and cognitive dimensions of binge eating. 
Data Analysis
The obtained data were analyzed by the Pearson correlation coefficient and path analysis of structural equations using SPSS v. 24 and Liserl 8 software. To determine the significance of the relationship between the bootstrap tests in the macro program, the Preacher and Hayes test using SPSS v. 24 software was performed. Bootstrap is the most powerful and logical way to indicate indirect effects [14]. The final data analysis was performed on 283 participants.
Results 
In this study, 283 students with an age range of 40-18 years and a mean age of 23.70±3.98 years participated. The mean body mass index of the participants was 23.32±3.49 kg/m2. Among participants, 176 cases (62.2%) were men and 107 (cases 37.8%) were women.
The results showed that the severity of binge eating symptoms had a positive and significant relationship with body image shame and body image victimization experiences. Furthermore, body image shame and self-criticism/self-reassurance had a positive and significant relationship with body image victimization experiences.
In the current study, the hypothetical model examined the relationship between the severity of binge eating symptoms and body image victimization experiences mediated by body image shame and self-criticizing. Initially, the assumptions of structural equation modeling were met. The direct standard coefficient of body image victimization experiences, body image shame, and self-criticizing of the severity of binge eating symptoms was significant (Figure 1). Therefore, the evidence was sufficient to support this hypothesis.  
The index in Table 1 shows that the proposed model had a good fit [15, 16, 17].


To fit the model, the ratio of Chi-square to freedom must be less than 3. Values ​​less than 0.10 have also been suggested for the root mean square error index (RMSEA). For comparative fit index (CFI), the goodness of fit (GFI), and normed fit index (NFI), values ​​of 0.90 to 1 indicate a good fit [15, 16, 17].
As shown in Table 2, the path of victimization experienced with the severe binge eating symptoms mediated by body image shame was significant.


The path of body image victimization experiences was highly significant too, with binge eating mediated by self-criticizing.
Discussion
The finding of this study was consistent with previous studies [1, 2, 3, 4] asserting that early experiences related to body image play a critical role in eating problems and the severity of binge eating symptoms in later years. Also, binge eating symptoms can be an ineffective way to deal with threats and fears caused by the negative view of others. On the other hand, the results demonstrated that body image shame could mediate the relationship between body image victimization experiences and the severity of binge eating symptoms. Accordingly, people with binge eating symptoms are continually checking their bodies and always criticizing or making sure of their body shape and condition. In other words, self-criticism and body image distortion may unconsciously lead to an increase in negative emotions, which is a strong predictor of periods of binge eating and exacerbation of binge eating symptoms.
This study had several limitations. This research had a cross-sectional correlation design; thus, causal results cannot be obtained and experimental designs can be used in future research. Self-report tools were used to collect the data, which are not accurate enough. The sample of this study was nonclinical, which limits generalizations to clinical groups. Therefore, future research can consider these limitations and examine this research in clinical samples using objective tools.
The present study has important implications for the conceptualization and treatment of binge eating symptoms in the Iranian sample. Therefore, researchers and clinicians can consider the effect of these factors on binge eating disorder treatment.

Ethical Considerations
Compliance with ethical 
This article is taken from the thesis of Zahra Salarian Koljegi in the Department of Clinical Psychology, Tehran University of Social Welfare and Rehabilitation Sciences and registered with the code of ethics IR.USWR.REC.1398.024.

Funding
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Authors contributions
Supervision of research implementation and data accuracy: Hamid Poursharifi; Preparing the draft of the article, making corrections and scientific supervision of the method of writing the report in accordance with the standards, finalizing the writing and editing, methodology and analysis: Zahra Salarian Koleji; Sources, research and review: Farishte Momeni and Behrouz Dolatshahi.

Conflicts of interest
The authors declared no conflict of interest.

Acknowledgements
The cooperation of the staff and students of Shahid Beheshti University of Medical Sciences who helped us in conducting this study is sincerely appreciated.



References

1. American Psychiatric Association. Diagnostic and statistical manual of mental disorders (DSM-5®). Washington: American Psychiatric Publisher; 2013. [Link]
2. Verstuyf J, Vansteenkiste M, Soenens B, Boone L, Mouratidis A. Daily ups and downs in women's binge eating symptoms: The role of basic psychological needs, general self-control, and emotional eating. Journal of Social and Clinical Psychology. 2013; 32(3):335. [DOI:10.1521/jscp.2013.32.3.335]
3. Kessler RC, Berglund PA, Chiu WT, Deitz AC, Hudson JI, Shahly V, et al. The prevalence and correlates of binge eating disorder in the world health organization world mental health surveys. Biological Psychiatry. 2013; 73(9):904-14. [DOI:10.1016/j.biopsych.2012.11.020] [PMID] [PMCID]
4. Sahlan RN, Saunders JF, Mond JM, Fitzsimmons-Craft EE. Eating disorder symptoms among adolescent boys and girls in Iran. International Journal of Eating Disorders. 2021; 54(1):19-23.  [DOI:10.1002/eat.23420] [PMID] [PMCID]
5. Belli H, Ural C, Akbudak M, Sagaltıcı E. Levels of childhood traumatic experiences and dissociative symptoms in extremely obese patients with and without binge eating disorder. Nordic Journal of Psychiatry. 2019; 73(8):527-31. [DOI:10.1080/08039488.2019.1662085] [PMID]
6. Quilliot D, Brunaud L, Mathieu J, Quenot C, Sirveaux MA, Kahn JP, et al. Links between traumatic experiences in childhood or early adulthood and lifetime binge eating disorder. Psychiatry Research. 2019; 276:134-41. [DOI:10.1016/j.psychres.2019.05.008] [PMID]
7. Pinto-Gouveia J, Matos M. Can shame memories become a key to identity? The centrality of shame memories predicts psychopathology. Applied Cognitive Psychology. 2011; 25(2):281-90. [DOI:10.1002/acp.1689]
8. Chen X, Luo YJ, Chen H. Body image victimization experiences and disordered eating behaviors among Chinese female adolescents: The role of body dissatisfaction and depression. Sex Roles. 2020; 83(7):442-52. [DOI:10.1007/s11199-020-01122-4]
9. Duarte C, Pinto-Gouveia J, Ferreira C. Escaping from body image shame and harsh self-criticism: Exploration of underlying mechanisms of binge eating. Eating Behaviors. 2014; 15(4):638-43.[DOI:10.1016/j.eatbeh.2014.08.025] [PMID]
10. Duarte C, Ferreira C, Pinto-Gouveia J. At the core of eating disorders: Overvaluation, social rank, self-criticism and shame in anorexia, bulimia and binge eating disorder. Comprehensive Psychiatry. 2016; 66:123-31. [DOI:10.1016/j.comppsych.2016.01.003] [PMID]
11. Mustapic J, Marcinko D, Vargek P. Body shame and disordered eating in adolescents. Current Psychology. 2017; 36(3):447-52.[DOI:10.1007/s12144-016-9433-3]
12. Duarte C, Pinto-Gouveia J, Stubbs R. The prospective associations between bullying experiences, body image shame and disordered eating in a sample of adolescent girls. Personality and Individual Differences. 2017; 116:319-25. [DOI:10.1016/j.paid.2017.05.003]
13. Palmeira L, Pinto-Gouveia J, Cunha M, Carvalho S. Finding the link between internalized weight-stigma and binge eating behaviors in Portuguese adult women with overweight and obesity: The mediator role of self-criticism and self-reassurance. Eating behaviors. 2017; 26:50-4. [DOI:10.1016/j.eatbeh.2017.01.006] [PMID]
14. Olvera N, McCarley K, Matthews-Ewald MR, Fisher F, Jones M, Flynn EG. Pathways for disordered eating behaviors in minority girls: The role of adiposity, peer weight-related teasing, and desire to be thinner. The Journal of Early Adolescence. 2017; 37(3):367-86. [DOI:10.1177/0272431615609155]
15. Duarte C, Pinto-Gouveia J. Body image as a target of victimization by peers/parents: Development and validation of the body image victimization experiences scale. Women Health. 2017; 57(9):1061-79. [DOI:10.1080/03630242.2016.1243603] [PMID]
16. Duarte C, Pinto-Gouveia J, Ferreira C, Batista D. Body image as a source of shame: A new measure for the assessment of the multifaceted nature of body image shame. Clinical Psychology & Psychotherapy. 2015; 22(6):656-66. [DOI:10.1002/cpp.1925] [PMID]
17. Duarte C, Pinto-Gouveia J, Ferreira C. Ashamed and fused with body image and eating: Binge eating as an avoidance strategy. Clinical Psychology & Psychotherapy. 2017; 24(1):195-202. [DOI:10.1002/cpp.1996] [PMID]
18. Duarte C, Pinto-Gouveia J. The impact of early shame memories in binge eating disorder: The mediator effect of current body image shame and cognitive fusion. Psychiatry Research. 2017; 258:511-7. [DOI:10.1016/j.psychres.2017.08.086] [PMID]
19. Gois AC, Ferreira C, Mendes AL. Steps toward understanding the impact of early emotional experiences on disordered eating: The role of self-criticism, shame, and body image shame. Appetite. 2018; 125:10-17. 7. [DOI:10.1016/j.appet.2018.01.025] [PMID]
20. Gilbert P, Clarke M, Hempel S, Miles JN, Irons C. Criticizing and reassuring oneself: An exploration of forms, styles and reasons in female students. British Journal of Clinical Psychology. 2004; 43(1):31-50. [DOI:10.1348/014466504772812959] [PMID]
21. Gilbert P, Irons C. Focused therapies and compassionate mind training for shame and self-attacking. In: P. Gilbert, editor. Compassion: Conceptualisations, research and use in psychotherapy. , Oxfordshire: Routledge; 2005. [Link]
22. Ferreira C, Matos M, Duarte C, Pinto-Gouveia J. Shame Memories and eating psychopathology: The buffering effect of self-compassion. European Eating Disorders Review. 2014; 22(6):487-94. [DOI:10.1002/erv.2322] [PMID]
23. Kelly AC, Carter JC. Why self-critical patients present with more severe eating disorder pathology: The mediating role of shame. British Journal of Clinical Psychology. 2013; 52(2):148-61. [DOI:10.1111/bjc.12006] [PMID]
24. Dakanalis A, Carrà G, Timko A, Volpato C, Pla-Sanjuanelo J, Zanetti A, et al. Mechanisms of influence of body checking on binge eating. International Journal of Clinical and Health Psychology. 2015; 15(2):93-104. [DOI:10.1016/j.ijchp.2015.03.003] [PMID] [PMCID]
25. Dunkley DM, Masheb RM, Grilo CM. Childhood maltreatment, depressive symptoms, and body dissatisfaction in patients with binge eating disorder: The mediating role of self-criticism. International Journal of Eating Disorders. 2010; 43(3):274-81. [DOI:10.1002/eat.20796] [PMID] [PMCID]
26. Kline RB. Principles and practice of structural equation modeling. New York: Guilford publications; 2015. [Link]
27. Khanjani S, Gharraee B, Farani AR, Foroughi A. Psychometric properties of Persian version of body image shame scale: A study in cosmetic surgery clinics. Iranian Journal of Psychiatry and Behavioral Sciences. 2020; 14(2):e99492. [DOI:10.5812/ijpbs.99492]
28. Castilho P, Pinto-Gouveia J, Duarte J. Exploring self-criticism: Confirmatory factor analysis of the FSCRS in clinical and nonclinical samples. Clinical Psychology & Psychotherapy. 2015; 22(2):153-64. [DOI:10.1002/cpp.1881] [PMID]
29. Savari Y, Mohagheghi H, Yarmohammadivasel M, Esbati M. [The effect of compassionate mind training on depression and anger rumination in students with depression symptoms (Persian)]. Journal of Psychological Studies. 2019; 15(2): 7-24. [DOI: 10.22051/PSY.2019.23565.1799]
30. Gormally J, Black S, Daston S, Rardin D. The assessment of binge eating severity among obese persons. Addictive Behaviors. 1982; 7(1):47-55. [DOI:10.1016/0306-4603(82)90024-7] [PMID]
31. Mootabi F, Moloodi R, Dezhkam M, Omidvar N. [Standardization of the Binge eating scale among Iranian obese population (Persian)]. Iranian Journal of Psychiatry. 2009; 4(4):143-6.
32. Preacher KJ, Hayes AF. Asymptotic and resampling strategies for assessing and comparing indirect effects in multiple mediator models. Behavior Research Methods. 2008; 40(3):879-91. [DOI:10.3758/BRM.40.3.879] [PMID]
33. Shah R, Goldstein SM. Use of structural equation modeling in operations management research: Looking back and forward. Journal of Operations Management. 2006; 24(2):148-69. [DOI:10.1016/j.jom.2005.05.001]
34. Hooper D, Coughlan J, Mullen MR. Structural equation modelling: Guidelines for determining model fit. Electronic Journal Of Business Research Methods. 2008; 6(1):53-60. [Link]
35. Hosseini E, Talepasand S, Rahimian Boogar I. Body image and eating problems: Testing a tripartite model. Iranian Journal of Psychiatry and Clinical Psychology. 2017; 23(2):192-207. [DOI:10.29252/nirp.ijpcp.23.2.192]
36. Marta-Simões J, Ferreira C, Mendes AL. Exploring the effect of external shame on body appreciation among Portuguese young adults: The role of self-compassion. Eating behaviors. 2016; 23:174-9. [DOI:10.1016/j.eatbeh.2016.10.006] [PMID]
37. Matos M, Pinto-Gouveia J, Duarte C. Internalizing early memories of shame and lack of safeness and warmth: The mediating role of shame on depression. Behavioural And Cognitive Psychotherapy. 2013; 41(04):479-93. [DOI:10.1017/S1352465813000350] [PMID]
38. Gilbert P. The evolution and social dynamics of compassion. Social and personality psychology compass. 2015; 9(6):239-54. [DOI:10.1111/spc3.12176]
39. Gilbert SC, Thompson JK. Body shame in childhood and adolescence: Relations to general psychological functioning and eating disorders. Body shame: Routledge; 2014. p. 69-88. [DOI:10.4324/9781315820255]