ORIGINAL RESEARCH

Body Mass Index, Nutritional Knowledge, and Eating Behaviors in Elite Student and Professional Ballet Dancers Matthew A. Wyon, PhD,*† Kate M. Hutchings, MSc,‡ Abigail Wells, MSc,* and Alan M. Nevill, PhD*

Objective: It is recognized that there is a high esthetic demand in ballet, and this has implications on dancers’ body mass index (BMI) and eating behaviors. The objective of this study was to examine the association between BMI, eating attitudes, and nutritional knowledge of elite student and professional ballet dancers.

Design: Observational design. Setting: Institutional. Participants: One hundred eighty-nine participants from an elite full-time dance school (M = 53, F = 86) and from an elite ballet company (M = 16, F = 25) volunteered for the study. There were no exclusion criteria. Interventions: Anthropometric data (height and mass), General Nutrition Knowledge Questionnaire (GNKQ), and the Eating Attitude Test—26 (EAT-26) were collected from each participant. Main Outcome Measures: Univariate analysis of variance was used to examine differences in gender and group for BMI, GNKQ, and EAT-26. Regression analyses were applied to examine interactions between BMI, GNKQ, and EAT-26. Results: Professional dancers had significantly greater BMI than student dancers (P , 0.001), and males had significantly higher BMI scores than females (P , 0.05). Food knowledge increased with age (P , 0.001) with no gender difference. Student dancers had a significant interaction between year group and gender because of significantly higher EAT-26 scores for females in years 10 and 12. Regression analysis of the subcategories (gender and group) reported a number of significant relationships between BMI, GNKQ, and EAT-26. Conclusions: The findings suggest that dancers with disordered eating also display lower levels of nutritional knowledge, and this may have an impact on BMI. Female students’ eating attitudes and BMI should especially be monitored during periods of adolescent development. Key Words: ballet, eating disorders, body mass index, nutrition knowledge (Clin J Sport Med 2014;24:390–396) Submitted for publication March 11, 2013; accepted October 8, 2013. From the *Research Centre for Sport, Exercise and Performance, University of Wolverhampton, Walsall, United Kingdom, †National Institute for Dance Medicine and Science, Birmingham, United Kingdom, and ‡English Institute of Sport, Bisham Abbey, Marlow, United Kingdom. The authors report no conflicts of interest. Corresponding Author: Matthew A. Wyon, PhD, Research Centre for Sport, Exercise, and Performance, University of Wolverhampton, Gorway Rd, Walsall, West Midlands, United Kingdom WS1 3BD ([email protected]). Copyright © 2013 by Lippincott Williams & Wilkins

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INTRODUCTION It is recognized that athletic performance is enhanced by optimal nutrition and adequate recovery from exercise.1 Energy requirements must be met to maintain body weight, replenish glycogen stores, and provide essential components for tissue regeneration and repair.2 However, dietary inadequacies and nutrition-related knowledge deficits continue to persist among many athletes.2 The prevalence of low body weight body mass index (BMI) and disordered eating in the field of ballet is documented in the medical literature,3 and female elite dancers have been reported to weigh between 10% and 14% below their ideal weight for height.4 The esthetic demand of dance can generate high levels of body dissatisfaction and a motivation to be thin,5 and this creates a conflict between achieving an “acceptable” body image and acquiring optimal aerobic endurance and muscular strength.6 These contrasting goals may predispose the dancer to an increased risk of disordered eating behaviors that are confounded by psychosocial stressors.7 In addition, ballet, as a form of exercise, can be an inefficient method of burning calories,8,9 and therefore dietary constraint may be used for weight control in a drive to maintain a lean physique.10 The constant requirement of a lean physique has also been linked to increased healing times; dancers with low percentage of body fat are more prone to injury and take longer to recover than their healthier counterparts.11 The prevalence of eating disorders (ED) and disordered eating patterns (DE) in athletes varies significantly in the literature with estimates between 1% and 62%.12 Esthetic sports that require leanness or a specific body weight are at higher risk of developing DE than nonesthetic sports.13 One of the largest studies to date14 has shown a significant increase in ED in females competing in endurance, weight category, and esthetic sports, and these characteristics have also been seen within dance populations, especially ballet2–4,15 but also in other genres.6 The reasons for the increased prevalence of ED among certain subgroups of athletes have been open to considerable speculation;16 the most common view has been that the pressures to diet and become thin may actually trigger ED in those with specific vulnerabilities.17 Alternatively, it may be that they attract people with preexisting ED or certain personalities that may predispose them to develop ED.18 The concept of disordered eating behaviors must be distinguished from a clinical diagnosis of an ED. Disordered eating patterns are defined as a continuum from ED (eg, anorexia nervosa bulimia nervosa) to preoccupations with Clin J Sport Med  Volume 24, Number 5, September 2014

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weight and restrictive eating.1 There are distinct differences, with DE manifesting as a habitual reaction to external stressors and requires education and identification of the precipitating factors, whereas an ED is classified as a psychiatric illness,19 which requires specific medical interventions. The consequence of disordered eating affects both metabolism and endocrine function and in the female athlete can lead to the development of the “female triad.”20 The nutritional intake of athletes is a critical determinant of their athletic performance, but in contrast to the evidence of ED in dance, there are relatively few studies in the literature examining both eating behaviors and knowledge of nutrition. Research indicates that female ballet dancers have a lower BMI21 and a higher preoccupation with weight, eating habits, and body perfectionism than the general population.22 However, the relationship between BMI, nutritional knowledge, and eating behaviors in ballet dancers is unclear. The aim of this study was to examine eating attitudes and nutritional knowledge of both elite student and professional ballet dancers in relation to their BMI. Two selfcompleted questionnaires were used: the Eating Attitudes Test—26 (EAT-26)23 and the General Nutrition Knowledge Questionnaire (GNKQ).24 The EAT-26 is not designed to give a specific diagnosis of an ED; however, it is used as a screening instrument and has been found to be effective with clinical, subclinical, athletic,18 and dance populations. The GNKQ is divided into 3 sections: dietary recommendations, sources of food/nutrients, and choosing everyday food. The use of BMI as an indicator of a person’s “thinness” or “thickness” was initially intended for population studies but has now been used for individual diagnosis for under- or overweight and the risk of disease. The formula (height/ weight2) was developed for sedentary populations, and therefore, complications arise when used with power athletes; their increased muscle mass often results in an “obese” diagnosis. Dancers, and especially ballet dancers, do not have the same muscle mass as observed in age-matched power athletes10 and therefore are not prone to this misdiagnosis. Other measurements of “fatness,” such as body fat and waist circumference, are rarely used with dance populations; the former is avoided, especially in female dancers, as it can enhance disordered eating tendencies. Therefore, along with a historical precedent in published data, BMI, as both an absolute score and as an age-related percentile, was chosen as the outcome measure for this study. The use of age-related percentiles is important within any study that has adolescent participants as it takes into account adolescent growth spurts. The initial objective was to test for significant differences between professional and student dancers in their BMI, nutritional knowledge, and eating behaviors, secondly to test for significant gender differences within these parameters, and thirdly to test for significant relationships between the variables.

METHODOLOGY One hundred eighty participants volunteered for the study from an elite full-time ballet school (n = 139, 77% of school; age range 11-18 years) and an elite touring ballet company (n = 41, 75% of company; age range 19-39 years).  2013 Lippincott Williams & Wilkins

BMI, EAT-26, and GNKQ in Ballet Dancers

The student participants engaged in 4-6 hours of predominant ballet training 6 days a week, whereas the professional dancers were contracted to dance for 38 hours a week. There were no exclusion criteria for the study, and each participant signed informed consent; parental/guardian consent was also gained for all the student participants. Ethical approval for the study was given by the lead author’s institution. The demographics and anthropometric data of each dancer were collected before the administration of the questionnaires (Table). Body mass index (kilograms per square millimeter) was calculated from the measured height (0.1 cm) and weight (0.1 kg). The GNKQ and EAT-26 questionnaires were completed in an isolated environment with supervision from an independent medical professional over a 3-day period. The medical professional was in the room to oversee the process, to collect the questionnaires on completion, and to allow the participants to indicate they would like to talk further about any issues raised without having to go through the artistic staff. High scores in the GNKQ indicated good nutritional knowledge, and within the EAT-26, the higher the score the more disordered the eating behavior; it is suggested that scores above 20 require medical referral. Adolescent data were categorized according to academic year (7-13), and BMI was reported as an age-related percentile using the World Health Organization’s 2007 gender-specific charts (Table). A 2 · 2 (gender · group) univariate analysis of variance was used to determine if a statistical difference existed for BMI, percentile BMI, EAT-26, and GNKQ. Linear and quadratic regression analyses were computed to examine the relationship between BMI, EAT-26, and GNKQ. Statistical significance was set at P , 0.05.

RESULTS Professional dancers had significantly greater BMI than student dancers (P , 0.001); a significant gender-by-group interaction (P = 0.005) confirms that the gap between male and female dancers in BMI was greater in professional male dancers. Further analyses, using student year group as a category in addition to the professional dancers, also indicated significant differences because of year (P , 0.001). Gender differences were significant (P = 0.005), and a significant interaction between age groups by gender was observed (P = 0.001), where in older groups a divergence in BMI and percentile BMI was noted as male scores increased and females flatten out from year 10 (Table, Figure 1). General Nutrition Knowledge Questionnaire indicated that the professional dancers had significantly greater food knowledge than the student dancers (P , 0.001). Analysis by student year group in addition to the professional dancer group indicated a significant increase by year (P , 0.001) with no gender difference. There were no significant differences in EAT-26 scores between the professional and the student dancers though professionals and males had lower mean scores (Table). Yearby-year analyses reported no significant main effects for year group or gender. A significant interaction between year group and gender was noticed (P = 0.004) because of significantly www.cjsportmed.com |

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TABLE. Demographic, BMI, EAT-26, and GNKQ Descriptive Data for the Student and Professional Dancer Cohorts Year

Gender

7

Male Female Male Female Male Female Male Female Male Female Male Female Male Female Male Female

8 9 10 11 12 13 Professional

Age (y) 12 11 13 12 13 13 15 14 15 15 17 16 18 17 30 27

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

0.52 0.49 0.52 0.47 0.53 0.47 0.53 0.47 0.52 0.43 0.96 0.52 0.49 0.61 5.42 4.61

Height (m) 1.48 1.51 1.58 1.55 1.63 1.59 1.68 1.63 1.75 1.62 1.81 1.59 1.85 1.62 1.77 1.65

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

0.09 0.11 0.06 0.06 0.07 0.06 0.09 0.04 0.06 0.04 0.12 0.04 0.06 0.10 3.91 2.65

Mass (kg) 36.7 38.8 46.7 40.9 47.7 45.6 54.0 50.1 61.1 49.4 69.5 45.8 72.4 52.3 69.2 51.9

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

7.86 6.26 5.16 5.58 5.76 2.98 8.91 6.44 6.14 4.28 13.08 4.65 6.51 4.42 4.51 2.57

higher EAT-26 scores for females in years 10 and 12 (Figure 2). These elevated scores were because of 5 participants in year 10 and 3 in year 12 (EAT-26 scores above 2015,17,23); once these were removed, the effect disappeared. Linear and quadratic regression analyses of the subcategories (gender and group) reported a number of significant relationships between BMI, GNKQ, and EAT-26. Female student and professional dancers reported significant positive and negative quadratic associations between BMI and EAT-26, respectively (students, P = 0.014; professionals, P = 0.013), whereas the male participants reported no significant associations. General Nutrition Knowledge Questionnaire and EAT-26 reported significant associations only for professional dancers; both reported negative quadratic relationships (females P = 0.048, r = 2492, and males P = 0.040, r = 20.624). Within both the female student and professional participants, GNKQ was positively associated with BMI (P = 0.002, r = 0.372, and P = 0.04, r = 0.567, respectively).

DISCUSSION The aim of this study was to examine eating attitudes and nutritional knowledge of both elite student and professional ballet dancers. It was unique in that unlike many previous studies,3,25 the cohort consisted of both elite student and professional male and female ballet dancers. Previous research has mainly investigated high-level student ballet dancers about to embark on a professional career,3,6 whereas this study has enabled the comparison between professionals and students. The incidence of medical referral for possible ED or disordered eating (EAT-26 scores above 20) was 0% for professional cohorts, whereas previous studies reported an incidence rate of 33%25; this could be for a number of reasons, including better initial selection of company members or the artistic director having a different ideal body shape. The student cohort incidence was 9.4% (males 1.3%, females 8.1%), which was similar to the literature.6

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BMI (kg/m2) 16.5 15.9 18.7 16.9 17.9 18.1 19.0 18.9 19.8 18.9 21.2 18.2 21.9 20.1 21.9 18.9

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

1.99 0.85 1.08 1.37 1.07 1.00 1.89 1.83 1.49 1.77 2.28 1.78 1.25 3.07 1.02 0.66

BMI Percentile 17.2 24.0 46.3 22.3 30.8 23.0 37.6 21.9 40.8 25.5 47.5 15.3 45.4 28.2 42.4 19.8

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

23.11 15.86 15.81 19.95 16.04 9.98 24.21 15.35 22.14 16.56 30.92 13.63 14.95 26.41 14.37 8.47

EAT-26 3 2 6 3 8 3 1 14 4 6 6 14 9 7 3 4

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

2.68 1.52 3.27 3.09 12.14 2.73 1.48 13.41 3.64 5.41 2.65 11.67 8.18 8.76 4.17 4.51

GNKQ 34 32 35 32 30 34 33 40 42 40 41 39 44 44 54 51

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

9.43 9.59 15.19 8.73 16.57 9.41 5.33 6.45 5.71 7.59 9.09 7.28 8.57 7.69 6.51 7.18

The observed difference in BMI between professional and student dancers is probably because of increased muscle mass in the former group, though it should be recognized that the BMI data for the professional dancers were higher than previously reported for both male and female dancers.10 It is known that high-level training enhances muscle mass, which may account for the higher BMI seen in the present male cohort. Future research should assess the relationship between BMI and body composition within this population to examine whether they are similar to athletic or nonathletic populations.26 The observed gender differences are consistent with previous studies.8,9 It is recognized that BMI as a measure of body composition can lead to misclassification of athletes (as a low body weight can be attributed to a lower lean body mass). In comparison with normal child BMI development,27 the female students’ mean BMI tracked between the 15th and 30th percentiles across the cohort years 7 to 13 (12-18 years old) and the male students’ mean BMI tracked between the 17th to 47th percentiles. Early research had highlighted the prevalence of poor nutritional knowledge and practices,3,15 and in recent years, the profession has sought to combat this through increased education. The school had timetabled specific nutrition and cooking classes throughout the academic years to make sure that their graduates were prepared for professional life. The significant difference between the scores of the students and professionals is probably because of the latter having to implement this knowledge into their daily lives as the student dancers were at a boarding school. Esthetic sports and dance, where leanness or a specific weight category is important, are often prone to disordered eating.3,6 Work by Hamilton et al4 highlighted the specific concerns of disordered eating practices within classical ballet companies, though this cohort does not support the findings of these previous studies in dance or esthetic sports. Whether this is because of the company’s recruitment policy where they select dancers with “healthier” BMIs than previously  2013 Lippincott Williams & Wilkins

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FIGURE 1. The gender differences in absolute and percentile BMI development across the student and professional dancer cohorts.

reported within the profession cannot be ascertained from the current data, but it is accompanied with the dancers having a good level of nutritional knowledge, which may be the result of a change in the profession’s attitude toward ultraleanness. Within this study, the professional dancers had a lower EAT-26 score compared with the student cohort, which possibly suggests that those who graduate from an elite ballet school and are selected through audition to work professionally either have the profession-required body shape and do not have to adhere to disordered eating practices to maintain it or drop out as they cannot cope with the much greater physical demands of the profession.  2013 Lippincott Williams & Wilkins

The analysis of the student cohort highlighted the previously reported tendencies for disordered eating with ballet student populations.3,6 The 2 observed peaks within the female student data are caused by 5 students in year 4 (;15 years old) and 3 in year 12 (;17 years old) that had EAT-26 above 20.2 Year 4 is around the age when many young female dancers are beginning to start puberty; this is later than the normal population because of the increased workload and lower BMI of this population.28 This sudden rise in higher nutritional concern for females could be prompted by the bodily changes that occur during puberty and body composition altering to accumulate, approximately, a further 5% of www.cjsportmed.com |

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FIGURE 2. The gender differences in EAT-26 scores across the student and professional dancer cohorts.

body fat.28 This may be misinterpreted as “putting on weight” instead of natural development, hence an overconcern with food and dietary intake, the one thing that they feel they can control. The second observable peak (year 12) could be partly because of new students joining the school, often from overseas, for 2 to 3 years of intensive dance training. It was interesting to note that most of the high EAT-26 scores in this year group were submitted by international students, and this could have contributed to the overall look of the data, as knowledge and attitudes toward nutrition could perhaps be different because of the cultural influences. Because of the limited scope of the present study that has not collected longitudinal data, these peaks could just be a localized effect of that year group that have manifested because of heightened perfectionism and low self-esteem.7 The observed positive association between BMI and EAT-26 scores for the female student dancers is an effect of age as the older students who had higher BMI also reported greater mean EAT-26 scores, as previously reported. The 5 students in year 10 and 3 in year 12 who had EAT-26 scores above 20 recorded BMI data at the extremes of their year cohorts, ,17 or .23 BMI. The female professional dancers reported a moderate negative correlation between BMI and EAT-26, with dancers with BMI ,18 having the greatest EAT-26 scores. This is possibly because of these dancers having to achieve a weight and leanness below their “natural” ideal body weight and has resulted in disordered eating practices because of caloric restriction. In a national survey, the mean BMI of female ballet dancers was 19.6 6 2.1,29 and therefore, a dancer with a BMI .23 would be considered overweight for this population. One of the fundamental issues for dancers that leads to caloric reduction practices is that dance has a low energy expenditure. Even though dance activity can reach intensities above 9 Metabolic Equivalent of Task (METS), the majority of the professional’s dancing day is spent below 3 METS8 because of its intermittent nature. The drive

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for leanness also means that female dancers have relatively low amounts of muscle mass in the upper body that further decreases their BMI and basal metabolic rate.10 Systematic review30 of 29 studies on athletic nutritional knowledge reported that athletes’ knowledge was equal to or better than nonathletes and also female athletes scored higher than their male counterparts. The present study noted a rise in nutritional knowledge with age implying that nutritional education may help dancers in achieving a healthy body weight. Within the present study, both male and female professional dancers had moderate negative associations between EAT-26 and GNKQ scores, but the present study design does not allow an examination of whether a nutritional knowledge intervention could have an effect on eating practices as demonstrated by the EAT-26. The interpretation of the relationship between BMI with eating patterns and nutritional knowledge raises a number of important issues. Studies in the ballet population have often focused on the clinical diagnoses of ED3,18 rather than disordered eating behaviors. The results from this cohort and other studies raise the question regarding the actual prevalence of disordered eating in dancers (anorexia nervosa 7%-19%, bulimia nervosa 10%-15%)3,4 and the use of conventional assessment methods. To our knowledge, the relationship between nutritional knowledge and BMI has not previously been examined in this population, and the findings add to the complex issues around weight control in ballet dancers. The variables influencing BMI in athletes competing in esthetic sports are multifactorial, and it is difficult to ascertain whether the athlete’s eating behavior is influenced by nutritional knowledge or whether dietary restriction overrides the decision. The findings from this study reflect the need to address both eating behaviors and nutritional knowledge in managing underweight female dancers. The relationship between nutritional knowledge and eating behaviors showed a negative correlation between EAT 2013 Lippincott Williams & Wilkins

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26 and GNKQ scores in both male and female professional dancers, that is, nutritional knowledge had a positive effect on eating behaviors. This relationship has not previously been documented in the ballet literature, but similar findings have been shown in endurance athletes. Elite female ballet dancers have been shown to display increased image distortion, neurotic perfectionism symptoms, and higher levels of diet concerns.4,15 The use of dietary restriction as a means of weight control may in theory be complicated by a deficit in nutritional knowledge, and this may compound the difficulty in maintaining a perceived body image. Nutritional education has a role in helping this population achieve a healthy but acceptable body weight; however, interventions need to address both nutrition education and psychological therapy as nutrition advice in isolation is insufficient in addressing the issues. There are limitations of this study that restrict the wider application of the results. First, the sampling methods involved voluntary participation, and potentially, dancers “at risk” of an ED or those with a lower BMI may have self-selected themselves from the study. Some dancers may have declined participation because of the nature of the data or concerns about the findings being shared outside the respective medical teams although anonymity was assured. In addition, the findings were extrapolated without reference to a control group.

CONCLUSIONS Professional female dancers with a lower BMI were found to display higher levels of DE on the EAT-26 and less knowledge of nutrition. Both male and female professional dancers showed moderate negative correlations between EAT-26 and GNKQ scores, suggesting that dancers with disordered eating also display lower levels of nutritional knowledge. Student dancers showed a year-by-year improvement in nutritional knowledge, but a minority reported disordered eating profiles at the age of puberty and 2 years later as they entered their final 2 years of training. The analysis highlights the issues surrounding the issues of maintaining an esthetic body shape in this highpressured environment. Future longitudinal studies are needed to enhance our knowledge of the impact eating behaviors and nutritional knowledge have on body composition in ballet dancers and how educational interventions can positively be employed.

Practical Implications 1. Professional dancers should be monitored for nutritional knowledge and BMI as indicators of potential disordered eating practices. 2. Educational programs focused on nutritional knowledge within vocational dance schools have a beneficial effect on BMI and eating attitudes. 3. Coaching/teaching staff need to be knowledgeable on how the body prepares for puberty and provide support especially to female dancers during this physiological change.  2013 Lippincott Williams & Wilkins

BMI, EAT-26, and GNKQ in Ballet Dancers

4. Body mass index should be used with care when assessing a dancer as its relationship to body composition has not been ascertained, and in other elite groups, the BMI is higher than expected because of increased muscle mass. REFERENCES 1. Wein D, Micheli L. Nutrition, eating disorders, and the female athlete triad. In: Mostofsky D, Zaichkowsky L, eds. Medical and Psychological Aspects of Sport and Exercise. Morgantown, WV: Fitness Information Technology; 2002:91–111. 2. Dotti A, Fioravanti M, Balotta M, et al. Eating behaviour of ballet dancers. Eat Weight Disord. 2002;7:60–67. 3. Abraham S. Characteristics of eating disorders among young ballet dancers. Psychopathology. 1996;29:223–229. 4. Hamilton L, Brooks-Gunn J, Warren M, et al. The role of selectivity in the pathogenesis of eating problems in ballet dancers. Med Sci Sports Exerc. 1988;20:560–565. 5. Byrne S, McLean N. Elite athletes: effects of the pressure to be thin. J Sci Med Sport. 2002;5:80–94. 6. Nordin-Bates S, Walker I, Redding E. Correlates of disordered eating attitudes among male and female young talented dancers: findings from the UK Centres for Advanced Training. Eat Disord. 2011;19:211–233. 7. Carr S, Wyon MA. The influence of goal orientation, trait anxiety, and perfectionism on dance students’ current perceptions of the motivational climate. J Dance Med Sci. 2003;7:105–114. 8. Twitchett E, Angioi M, Koutedakis Y, et al. The demands of a working day among female professional ballet dancers. J Dance Med Sci. 2010; 14:127–132. 9. Wyon MA, Abt G, Redding E, et al. Oxygen uptake during modern dance class, rehearsal and performance. J Strength Cond Res. 2004;18: 646–649. 10. Koutedakis Y, Jamurtas A. The dancer as a performing athlete: physiological considerations. Sports Med. 2004;34:651–661. 11. Twitchett E, Angioi M, Metsios G, et al. Body composition and ballet injuries: a preliminary study. Med Probl Perform Art. 2008; 23:93–98. 12. Byrne S, McLean N. Eating disorders in athletes: a review of the literature. J Sci Med Sport. 2001;4:145–159. 13. Torstveit M, Rosenvinge J, Sundgot-Borgen J. Prevalence of eating disorders and the predictive power of risk models in female elite athletes: a controlled study. Scand J Med Sci Sports. 2008;18:108–118. 14. Sundgot-Borgen J, Torstveit M. Prevalence of eating disorders in elite athletes is higher than in the general population. Clin J Sport Med. 2004; 14:25–32. 15. Garner D, Garfinkel P, Rockert W, et al. A prospective study of eating disturbances in the ballet. Psychother Psychosom. 1987;48:170–175. 16. Raymond-Barker P, Petroczi A, Quested E. Assessment of nutritional knowledge in female athletes susceptible to the Female Athlete Triad syndrome. J Occup Med Toxicol. 2007;2:1–11. 17. Garner D, Rosen L, Barry D. Eating disorders in athletes. In: Child and Adolescent Psychiatric Clinics of North America. New York, NY: W.B. Saunders; 1998:839–857. 18. Sundgot-Borgen J. Risk and trigger factors for the development of eating disorders in female elite athletes. Med Sci Sports Exerc. 1994; 26:414–419. 19. American Psychiatric Association. Diagnostic and Statistical Manual. 4th ed. Washington, DC: American Psychiatric Association; 1994. 20. Torstveit M, Sundgot-Borgen J. The female athlete triad: are elite athletes at increased risk? Med Sci Sports Exerc. 2005;37:184–193. 21. Twitchett E, Brodrick A, Nevill AM, et al. Does physical fitness affect injury occurrence and time loss due to injury in elite vocational ballet students? J Dance Med Sci. 2010;14:26–31. 22. Neumärker K, Bettle N, Bettle O, et al. The eating attitudes test: comparative analysis of female and male students at the Public Ballet School of Berlin. Eur Child Adolesc Psychiatry. 1998;7:19–23. 23. Garner M, Olmsted M, Bohr Y, et al. The eating attitudes test: psychometric features and clinical correlates. Psychol Med. 1982;12: 871–878. 24. Parmenter K, Wardle J. Development of a general nutrition knowledge questionnaire for adults. Eur J Clin Nutr. 1999;53:298–308.

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25. Brooks-Gunn J, Warren MP, Hamilton LH. The relation of eating problems and amenorrhea in ballet dancers. Med Sci Sports Exerc. 1987;19:41–44. 26. Nevill A, Winter E, Ingham S, et al. Adjusting athletes’ body mass index to better reflect adiposity in epidemiological research. J Sports Sci. 2010; 28:1009–1016. 27. Fryar C, Gu Q, Ogden C. Anthropometric reference data for children and adults: United States, 2007–2010. National Center for Health Statistics. Vital Health Stat. 2012;11:201.

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Clin J Sport Med  Volume 24, Number 5, September 2014 28. Lindholm C, Hagenfeldt K, Ringertz B- M. Pubertal development in elite juvenile gymnasts: effects of physical training. Acta Obstet Gynecol Scand. 1994;73:269–273. 29. Laws H. Fit to Dance 2-Report of the Second National Inquiry Into Dancers’ Health and Injury in the UK. London, United Kingdom: Newgate Press; 2005. 30. Heaney S, O’Connor H, Michael S, et al. Nutrition knowledge in athletes: a systematic review. Int J Sport Nutr Exerc Metab. 2011;21:248–261.

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Body mass index, nutritional knowledge, and eating behaviors in elite student and professional ballet dancers.

It is recognized that there is a high esthetic demand in ballet, and this has implications on dancers' body mass index (BMI) and eating behaviors. The...
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