Body image dissatisfaction and its relationship with nutritional status, body fat, and anorexia and bulimia symptoms in adolescents

Abstracts

Objetivos: Identificar a prevalência de insatisfação com a imagem corporal e de sintomas de anorexia e bulimia em adolescentes do sexo feminino da cidade de Santa Maria (RS) e verificar a associação da insatisfação com a imagem corporal com estado nutricional, adiposidade corporal e sintomas de anorexia e bulimia. Método: Foram analisadas 258 adolescentes do sexo feminino (11 a 13 anos), estudantes de escolas públicas. Aplicou-se o Body Shape Questionnaire e o Teste de Atitudes Alimentares (EAT-26). Foram calculados o índice de massa corporal e o percentual de gordura. Foram utilizados o teste qui-quadrado e a regressão logística. Resultados: A prevalência de insatisfação com a imagem corporal foi de 25,3% e a de sintomas de anorexia e bulimia foi de 27,6%. A insatisfação com a imagem corporal apresentou associação com o estado nutricional, sendo que as adolescentes com excesso de peso apresentaram maior insatisfação (razão de chances = 2,64; IC95%= 1,02-6,83). Conclusão: As prevalências de insatisfação corporal e sintomas de anorexia e bulimia foram elevadas. O estado nutricional parece ser o melhor preditor da insatisfação corporal.

Imagem corporal; anorexia; bulimia; antropometria

ORIGINAL ARTICLE

Body image dissatisfaction and its relationship with nutritional status, body fat, and anorexia and bulimia symptoms in adolescents

Cilene Rebolho Martins^I; Andreia Pelegrini^II; Silvana Corrêa Matheus^III; Edio Luiz Petroski^IV

^IMestranda, Programa de Pós-Graduação em Educação Física, Universidade Federal de Santa Catarina (UFSC), Florianópolis, SC, Brazil.

^IIDoutoranda, Programa de Pós-Graduação em Educação Física, UFSC, Brazil. Bolsista CAPES.

^IIIDoutora. Professora adjunta, Centro de Educação Física e Desportos, Universidade Federal de Santa Maria (UFSM), Santa Maria, RS, Brazil.

^IVPós-doutor. Professor titular, Centro de Desportos, UFSC, Brazil.

Correspondence

ABSTRACT

Objectives: To identify the prevalence of body image dissatisfaction and anorexia and bulimia symptoms in adolescent girls from the city of Santa Maria, Brazil, and to determine the association of body image dissatisfaction with nutritional status, body fat, and anorexia and bulimia symptoms.

Method: We investigated 258 adolescent girls (11 to 13 years) from public schools. The Body Shape Questionnaire and the Eating Attitudes Test (EAT-26) were used. Body mass index and percent body fat were calculated. The chi-square test and logistic regression were used.

Results: The prevalence of body image dissatisfaction was 25.3% and the prevalence of anorexia and bulimia symptoms was 27.6%. Body image dissatisfaction was associated with nutritional status, with overweight girls presenting higher dissatisfaction (OR = 2.64; 95%CI 1.02-6.83).

Conclusion: The prevalence rates of body image dissatisfaction and anorexia and bulimia symptoms were high. Nutritional status seems to be a better predictor of body image dissatisfaction.

Keywords: Body image, anorexia, bulimia, anthropometry.

INTRODUCTION

Body image may be defined as the perception one has of one's own body and one's feelings towards the size, shape, and constituent parts of one's body.¹

In women, the onset of puberty is associated with increased buildup of body fat, which often triggers increased body image dissatisfaction.^2,3 Furthermore, the media, peer pressure, parents, and society as a whole also have an influence on this context, as they basically impose thinness as the standard of beauty.^4,5

Body image dissatisfaction has been the focus of great interest among researchers, particularly due to its close association with eating disorders such as anorexia and bulimia.

Recent evidence has pointed to an increasing prevalence of body image dissatisfaction among adolescents.^2,3,6 Likewise, the number of anorexia and bulimia cases in this age range has been on the increase.^2,3,5 These eating disorders are characterized by a morbid fear of weight gain, an obsessive concern with food, a persistent desire for weight loss, and body image distortion,^5,7,8 leading to physical and psychological harm and increased morbidity and mortality.⁹

Eating disorder prevalence estimates vary according to method of study and sample choice. Overall, the prevalences of anorexia and bulimia range from 0.5 to 3.7% and 1.1 to 4.2% respectively.¹⁰ The general profile of a person with eating disorder is that of a white adolescent girl of high socioeconomic status; however, the population living with eating disorders is becoming increasingly heterogeneous, with such disorders now being diagnosed in preadolescents and among patients in lower socioeconomic strata.⁹

Few studies have addressed the relationship between body image dissatisfaction and symptoms of eating disorders in adolescents. One recent study found a strong association between these variables in girls between the ages of 10 and 19,⁶ but there is still a dearth of research to support these results.

Some studies have shown an association between nutritional status and body image dissatisfaction in adolescents¹¹ and college students.¹² However, this association must still be investigated in further detail, as these studies used quite simplistic statistical methods (chi-square testing). Thus far, no studies have addressed the possible association of body fat percentage with body image dissatisfaction in adolescents.

The present study thus sought to assess the prevalence of body image dissatisfaction and anorexia and bulimia symptoms in adolescent girls from Santa Maria, Rio Grande do Sul, and investigate the association between body image dissatisfaction and nutritional status, body fat percentage, and presence of anorexia and bulimia symptoms.

METHOD

This was a cross-sectional, descriptive study carried out in 2007 on a sample of female sixth- to eighth-grade students (age 11 to 13) attending public schools in Santa Maria, Rio Grande do Sul.

According to a school census carried out by the educational studies and research sector of the Brazilian Ministry of Education,¹³ the study population comprised 5,067 adolescents. We used a probability sample, stratified by geographical region (after division of the municipality of Santa Maria into three regions), school system (state and municipal), and age (11, 12, and 13).

Sample size was calculated according to the Fonseca & Martins equation,¹⁴ with an accepted relative error of 0.05 and a 95% confidence interval (95%)CI, for an estimated sample size of 166 adolescents. Fifteen schools (six state and nine municipal) were selected randomly. Data collection was performed by cluster of classes; all adolescents in the target age range who were present in the classroom on the day of data collection invited to participate in the study. The final sample comprised 258 girls.

Data collection was carried out in the schools themselves, during the class period, and consisted of two stages: 1) administration of body image questionnaires and the Eating Attitudes Test and 2) measurement of anthropometric parameters.

Body image dissatisfaction was assessed with the Portuguese version of the Body Shape Questionnaire (BSQ), translated by Cordás & Castilho¹⁵ from the original by Cooper et al.16 and validated by Manetta.¹⁷ The BSQ is a self-administered, Likert scale-based questionnaire made up of 34 multiple-choice questions, with each choice corresponding to a score of 1 to 6; higher scores are assigned to answers that reflect a greater concern with body image and greater feelings of self-deprecation due to physical appearance, particularly a perception of overweight. Depending on the score, respondents were considered satisfied (score <111) or dissatisfied (score ?111) with their body image (Cordás & Castilho¹⁵).

For assessment of anorexia and bulimia symptoms, we used the Eating Attitudes Test (EAT-26) devised by Garner et al.,¹⁸as translated to Portuguese by Nunes et al.8 and validated by Bighetti.¹⁹ The EAT-26 is also a self-administered, Likert scale-based, multiple-choice questionnaire, with each question having six possible choices (never, rarely, sometimes, often, usually, and always), which generate a score of 0 to 3. "Never", "rarely", and "sometimes" all correspond to 0 points each, whereas each "often", "usually", and "always" response adds 1, 2, and 3 points to the total score respectively. Question 25 is scored in the opposite direction, with a response of "often", "usually", or "always" generating no points and a choice of "sometimes", "rarely", or "never" generating a score of 1, 2, or 3 respectively. The overall score can range from 0 to 78. In the present study, adolescents with a total EAT-26 score of 20 or more were considered to display at-risk eating behaviors, as proposed elsewhere in the literature.^3,20,21 EAT-26 scores were thus categorized into positive (EAT+), in the presence of anorexia and bulimia symptoms, or negative (EAT-), in the absence of such symptoms.

Nutritional status was assessed by means of the body mass index (BMI; body mass/(height)²). Measurement of body mass and height was accomplished through standardized procedures.²² BMI values were categorized according to widely accepted cutoff points: underweight, BMI <18.5kg/m2;23 normal weight, BMI 18.5-24.9 kg/m²; overweight, BMI > 25 kg/m².²⁴

Adiposity was determined by body fat percentage (%F), as estimated by measurement of the triceps and subscapular skin folds;²⁵ %F was calculated according to the equation devised by Slaughter et al.²⁶ Body fat percentage was classified into three categories, adapted from the cutoff points established by Lohman:²⁷ normal (< 25%); high (26 to 35%), and very high (> 35%).

Descriptive analysis of the data obtained included means, standard deviations, and frequency distributions. We employed the chi-square test to assess the association between body image dissatisfaction and the following variables: nutritional status, body fat percentage, and anorexia and bulimia symptoms. These associations were also tested by logistic regression analysis, expressing odds ratio (OR). Body image dissatisfaction was the study endpoint or dependent variable. Two regression models were tested, one simple and one multiple (fitted with all variables). All statistical analyses were conducted in the SPSS 13.0 software package. The significance level was set at 0.05.

This study was authorized by the Rio Grande do Sul State Department of Education and the Santa Maria Municipal Department of Education, and was approved by the Human Subjects Research Ethics Committee of the Universidade Federal de Santa Maria (UFSM) (request no. 23081.013844/2007-48). In order to take part in the study, all adolescents in the sample were required to provide a free and informed consent form signed by their legal guardian.

RESULTS

The characteristics of the study sample are shown in Table 1, including means, standard deviations, and minimum and maximum values.

The prevalence of body image dissatisfaction and symptoms of anorexia and bulimia was 25.3% and 27.6%, respectively. Regarding nutritional status, 68.8%, 8.2%, and 23% of adolescents were classified as being underweight, normal-weight, and overweight, respectively. As for body fat percentage, 42.4% of participants fell into the "normal" category, 34.6% in the "high" category and e 23% were classified as "very high" (data not shown).

Body image dissatisfaction was associated with nutritional status (as measured by BMI) (p < 0.01) and body fat percentage (F%) (p < 0.01), as ascertained through the chi-square test (Figure 1). We found that increases in BMI and %F were followed by increased body image dissatisfaction among the adolescents in our sample.

Table 2 shows the results of logistic regression analysis of body image dissatisfaction against nutritional status, body fat percentage, and anorexia and bulimia symptoms. In the simple regression model, body image dissatisfaction was associated with both BMI and %F. When the model included all variables, body image dissatisfaction was associated only with BMI; overweight adolescents were 2.64 times more likely to be dissatisfied with their body image than those with a normal BMI.

DISCUSSION

The prevalence of body image dissatisfaction found in our sample (25.3%) was higher than that reported by other Brazilian studies that employed the same questionnaire.^6,11 Alves et al.⁶ found the prevalence of body image dissatisfaction to be 18.8% among female students aged 10 to 19 in Florianópolis, Santa Catarina. In a study by Branco et al.,¹¹ of students aged 14 to 19 in São Paulo, body image dissatisfaction was detected in 18.5% of respondents. The results found in our sample of adolescents from Santa Maria are similar to those reported in a Spanish study of adolescent girls (22.1%).²⁸

Furthermore, these results are similar to those obtained in prior studies of college students. Among students of the Nutrition program at the Universidade Federal do Rio de Janeiro (UFRJ), in Rio de Janeiro, 18.6% reported body image dissatisfaction.¹² In students of the Universidade Metodista de Piracicaba (São Paulo state), the prevalence of body image dissatisfaction was 17.3% and 22.2% among Nutrition and Psychology majors, respectively.²⁹

In terms of eating disorders, the results of this study were quite concerning, as the prevalence of anorexia and bulimia symptoms in our sample (27.6%) was higher than that found in other Brazilian^6,20,21,30 and international^3,28,31,32 studies, which suggests that a major proportion of the girls analyzed in the present study had risk factors for development of these disorders.

A study of public school students of both genders conducted in five municipalities in Minas Gerais found that 15.8% of girls aged 7 to 19 displayed abnormal eating behaviors.²⁰ Among 15- to 18-year-old students of a private school in São Paulo, the prevalence of anorexia and bulimia symptoms was 21.1%.³⁰ In a Canadian study, 14% of schoolgirls aged 12 to 18 were found to be at risk of developing anorexia and bulimia.³ In these particular studied, a score of 20 points on the EAT-26 was chosen as a cutoff. Other studies, which used an EAT-26 cutoff score of 21, found prevalence rates of 8.3,²¹ 15,³¹ and 15.6%⁶ for symptoms of anorexia and bulimia in adolescent girls. In a study conducted in Spain with the EAT-40 (the questionnaire from which the EAT-26 is derived), 16.3% of young women were found to have abnormal eating behaviors.²⁸

Public school students from Santa Maria thus appear to be more likely to develop anorexia and bulimia than adolescents in other regions of Brazil^6,20,21,30 and in other countries, such as Canada³ and the U.S.³¹

The literature has shown eating disorders to be quite prevalent among public school students,^6,11,32 which corroborates the results of the present study.

Body image dissatisfaction was not associated with symptoms of anorexia and bulimia, which was unexpected. Alves et al.6 reported a strong association between these two variables in adolescents from Florianópolis. Our finding may possibly be explained by the fact that body image dissatisfaction is present in adolescents regardless of whether they display behaviors that put them at risk of eating disorders.

In this study, we found an association between body image dissatisfaction and nutritional status; overweight adolescents were more dissatisfied with their body image than those with normal weight. These results corroborate the findings of Branco et al.,¹¹ who, in an analysis of male and female adolescents aged 14 to 19, found greater body image dissatisfaction among overweight and obese girls. However, Bosi et al.¹² found no association in a sample of college students; of those found to be dissatisfied in their study, 82.9% had normal weight, and only 11.4% were overweight.

Thus far, no published studies had reported the relationship between body fat percentage and body image dissatisfaction. Although we found an association between these variables on chi-square testing, it did not show on regression analysis. The context is therefore that of a growing number of adolescents who, despite having body fat percentages perfectly adequate for age, seek to be ever thinner and are thus dissatisfied with their body image. These results reflect the extent to which the media and society as a whole influence the body image of these girls by establishing an excessively thin standard of beauty.

The main limitation of the present study is its cross-sectional design, which makes it difficult to ascertain a causal relationship between variables. On the other hand, this was the first study to assess the prevalence of body image dissatisfaction and its association with anthropometric parameters and eating disorders in a sample of adolescents from Santa Maria, Rio Grande do Sul.

Our results revealed a high prevalence of body image dissatisfaction and anorexia and bulimia symptoms, showing a need for public school-based interventions seeking to prevent the development of eating disorders in female adolescents. In this study, symptoms of anorexia and bulimia were not associated with body image dissatisfaction, and neither was body fat percentage; nutritional status was, however, which indicates that overweight is predictive of greater body image dissatisfaction among adolescent girls.

REFERENCES

• 1. Slade PD. Body Image in anorexia nervosa. Br J Psychiatry Suppl. 1988;(2):20-2.
• 2. Campagna VN, Souza AS. Corpo e imagem corporal no início da adolescência feminina. Bol psicol. 2006;56(124):9-35.
• 3. Jones JM, Bennett S, Olmsted MP, Lawson ML, Rodin G. Disordered eating attitudes and behaviors in teenaged girls: a school-based study. CMAJ. 2001;165(5):547-52.
• 4. Tiggemann M, Pickering AS. Role of television in adolescent women's body dissatisfaction and drive for thinness. Int J Eat Disord. 1996;20(2):199-203.
• 5. Nunes MA, Olinto MT, Barros FC, Camey S. Influência da percepção do peso e do índice de massa corporal nos comportamentos alimentares anormais. Rev Bras Psiquiatr. 2001;23(1):21-7.
• 6. Alves E, Vasconcelos FA, Calvo MC, Neves J. Prevalência de sintomas de anorexia nervosa e insatisfação com a imagem corporal em adolescentes do sexo feminino do município de Florianópolis, Santa Catarina, Brasil. Cad Saude Publica. 2008;24(3):503-12.
• 7. Morandé G, Celada J, Casas JJ. Prevalence of eating disorders in a Spanish school-age population. J Adolesc Health. 1999;24(3):212-9.
• 8. Nunes MA, Bagatini LF, Abuchaim AL, Kunz A, Ramos D, Silva JA, et al. Distúrbios da conduta alimentar: considerações sobre o Teste de Atitudes Alimentares (EAT). Rev ABP-APAL. 1994;16(1):7-10.
• 9. Borges NJ, Sicchieri JM, Ribeiro RP, Marchini JS, dos Santos JE. Transtornos alimentares - quadro clínico. Medicina (Ribeirão Preto). 2006;39(3):340-8.
• 10. Practice guideline for the treatment of pacients with eating disorders (revision). American Psychiatric Association Work Group on Eating Disorders. Am J Psychiatry. 2000;157(1 Suppl):1-39.
• 11. Branco LM, Hilário MO, Cintra IP. Percepção e satisfação corporal em adolescentes e a relação com seu estado nutricional. Rev Psiquiatr Clin. 2006;33(6):292-6.
• 12. Bosi ML, Luiz RR, Morgado CM, Costa ML, de Carvalho RJ. Autopercepção da imagem corporal entre estudantes de nutrição: um estudo no município do Rio de Janeiro. J Bras Psiquiatr. 2006;55(2):108-13.
• 13. Sistema de Estatísticas Educacionais. [website] Brasil, Ministério da Educação. Disponível em: . Acessado em 15/04/2007.
• 14. Fonseca JS, Martins GA. Curso de Estatística. 6 ed. São Paulo: Atlas; 1996.
• 15. Cordás TA, Castilho S. Imagem corporal nos transtornos alimentares - Instrumento de Avaliação: "Body Shape Questionnaire". Psiquiatr Biol. 1994;2(1):17-21.
• 16. Cooper PJ, Taylor MJ, Cooper Z, Fairbun CG. The development and validation of the body shape questionnaire. Int J Eat Disord. 1987;6(4):485-94.
• 17. Manetta MC. Validade interna, dimensionalidade e desempenho da escala BSQ "Body Shape Questionaire" em uma população de estudantes universitários [dissertação]. São Paulo: Universidade Federal de São Paulo; 2002.
• 18. Garner DM, Olmsted MP, Bohr Y, Garfinkel PE. The eating attitudes test: psychometric features and clinical correlates. Psychol Med. 1982;12(4):871-8.
• 19. Bighetti F. Tradução e validação do Eating Attitudes Test (EAT-26) em adolescentes do sexo feminino na cidade de Ribeirão Preto - SP [dissertação]. Ribeirão Preto: Universidade de São Paulo; 2003.
• 20. Vilela JE, Lamounier JA, Dellaretti Filho MA, Barros Neto JR, Horta GM. Transtornos alimentares em escolares. J Pediatr (Rio J). 2004;80(1):49-54.
• 21. Chiodini JS, Oliveira MR. Comportamento alimentar de Adolescentes: aplicação do EAT-26 em uma escola pública. Saude Rev. 2003;5(9):53-8.
• 22. Alvarez BR, Pavan AL. Alturas e comprimentos. In: Petroski EL, ed. Antropometria: técnicas e padronizações. 3ª ed. Blumenau: Nova Letra; 2007. p. 31-44.
• 23. Cole TJ, Flegal KM, Nicholls D, Jackson AA. Body mass index cut offs to define thinness in children and adolescents: international survey. BMJ. 2007;335:194.
• 24. Cole TJ, Bellizzi MC, Flegal KM, Dietz WH. Establishing a standard definition for child overweight and obesity worldwide: international survey. BMJ. 2000;320(7244):1240-3.
• 25. Benedetti TR, Pinho RA, Ramos VM. Dobras cutâneas. In: Petroski EL, ed. Antropometria: técnicas e padronizações. 3ª ed. Blumenau: Nova Letra; 2007. p. 45-56.
• 26. Slaughter MH, Lohman TG, Boileau RA, Horswill CA, Stillman RJ, Van Loan MD, Bemben DA. Skinfold equations for estimation of body fatness in children and youth. Hum Biol. 1988;60(5):709-23.
• 27. Lohman TG. The use of skinfolds to estimate body fatness on children and youth. J Phisical Educ Recr Dance. 1987;58:98-103.
• 28. Ferrando DB, Blanco MG, Masó JP, Gurnés CS, Avellí MF. Eating attitudes and body satisfactions in adolescents: a prevalence study. Actas Esp Psiquiatr. 2002;30(4):207-12.
• 29. Stipp LM, Oliveira MR. Imagem corporal e atitudes alimentares: diferenças entre estudantes de nutrição e de psicologia. Saude Rev. 2003;5(9):47-51.
• 30. Dunker KL, Philippi ST. Hábitos e comportamentos alimentares de adolescentes com sintomas de anorexia nervosa. Rev Nutr. 2003;16(1):51-60.
• 31. Pastore DR, Fisher M, Friedman SB. Abnormalities in weight status, eating attitudes, and eating behaviors among urban high school students: correlations with self-esteem and anxiety. J Adolesc Health. 1996;18(5):312-9.
• 32. Rodriguéz A, Novalbos JP, Martínez JM, Ruiz MA, Fernández JR, Jiménez D. Eating Disorders and altered eating behaviors in adolescents of normal weight in a Spanish city. J Adolesc Health. 2001;28(3):338-45.

Publication Dates

• Publication in this collection
  28 July 2010
• Date of issue
  2010

History

• Received
  14 Apr 2009
• Accepted
  12 Sept 2009