Body image dissatisfaction: comparative evaluation of the association with nutritional status in university students

Abstracts

INTRODUCTION: The objective of this study was to investigate the association between body image dissatisfaction and two indicators of nutritional status in Brazilian university students, and also to identify the best predictor of body image dissatisfaction in Brazilian university students. METHODS: This was a cross-sectional study of 256 university students (128 males). Data were collected on demographics (age and sex), anthropometrics (body mass, stature and skinfold thickness), and body image (current silhouette and ideal silhouette). Body mass index (< 18.5 or ≥ 25.0 kg/m² = abnormal) and the sum of five skinfolds (≤ 30 or ≥ 62 and ≤ 43 or ≥ 76 mm = abnormal, for men and women, respectively) were then calculated. The analysis included descriptive statistics, proportionality testing, chi-square test and logistic regression. RESULTS: Mean age of the sample was 23.1 years (standard deviation = 5.3) and the frequency of body image dissatisfaction was 78.8%. Body image dissatisfaction was not associated with sex or body mass index. The multivariate analysis demonstrated that the odds ratio for abnormal sum of five skinfolds was 2.56. CONCLUSION: Body mass index was not a determinant of body image dissatisfaction, whereas the sum of five skinfolds proved to be a significant predictor of this disorder, irrespective of sex.

Body image; nutritional status; students; self-image

INTRODUÇÃO: O objetivo do estudo foi verificar a associação entre insatisfação com a imagem corporal e dois indicadores de estado nutricional em universitários brasileiros, assim como identificar o melhor preditor de insatisfação com a imagem corporal em universitários brasileiros. MÉTODOS: Trata-se de um estudo transversal, realizado com 256 universitários (128 homens). Foram coletados dados demográficos (sexo e idade), antropométricos (massa corporal, estatura e espessura de dobras cutâneas) e de imagem corporal (silhueta atual e silhueta ideal). O índice de massa corporal (< 18,5 ou ≥ 25,0 kg/m² = inadequado) e o somatório de espessura de cinco dobras cutâneas (≤ 30 ou ≥ 62 e ≤ 43 ou ≥ 76 mm = inadequado, para homens e mulheres, respectivamente) foram derivados subseqüentemente. A análise incluiu estatística descritiva, teste de proporção, qui-quadrado e regressão logística. RESULTADOS: A média de idade dos indivíduos foi de 23,1 anos (desvio padrão = 5,3), e a freqüência de insatisfeitos com a imagem corporal foi de 78,8%. A insatisfação com a imagem corporal não se associou ao sexo e ao índice de massa corporal. A análise multivariada demonstrou que a odds ratio associada ao somatório de espessura de cinco dobras cutâneas inadequado foi de 2,56. CONCLUSÃO: O índice de massa corporal não foi determinante de insatisfação com a imagem corporal, enquanto o somatório de espessura de cinco dobras cutâneas mostrou-se um preditor significativo desse distúrbio, independentemente do sexo.

Imagem corporal; estado nutricional; estudantes; auto-imagem

ORIGINAL ARTICLE

Body image dissatisfaction: comparative evaluation of the association with nutritional status in university students

Raildo da Silva Coqueiro^I; Edio Luiz Petroski^II; Andreia Pelegrini^III; Aline Rodrigues Barbosa^IV

^ISpecialist. Graduate student, Universidade Federal de Santa Catarina (UFSC), Florianópolis, SC, Brazil. Scholarship holder, CNPq

^IIPhD. Professor, Graduate Program in Physical Education, Núcleo de Pesquisa em Cineantropometria e Desempenho Humano (NuCIDH), UFSC

^IIIGraduate student, UFSC. Scholarship holder, CAPES

^IVPhD. Associate professor, Graduate Program in Physical Education, Núcleo de Pesquisa em Cineantropometria e Desempenho Humano (NuCIDH), UFSC

Correspondence

ABSTRACT

INTRODUCTION: The objective of this study was to investigate the association between body image dissatisfaction and two indicators of nutritional status in Brazilian university students, and also to identify the best predictor of body image dissatisfaction in Brazilian university students.

METHODOS: This was a cross-sectional study of 256 university students (128 males). Data were collected on demographics (age and sex), anthropometrics (body mass, stature and skinfold thickness), and body image (current silhouette and ideal silhouette). Body mass index (< 18.5 or ≥ 25.0 kg/m² = abnormal) and the sum of five skinfolds (≤ 30 or ≥ 62 and ≤ 43 or ≥ 76 mm = abnormal, for men and women, respectively) were then calculated. The analysis included descriptive statistics, proportionality testing, chi-square test and logistic regression.

RESULTS: Mean age of the sample was 23.1 years (standard deviation = 5.3) and the frequency of body image dissatisfaction was 78.8%. Body image dissatisfaction was not associated with sex or body mass index. The multivariate analysis demonstrated that the odds ratio for abnormal sum of five skinfolds was 2.56.

CONCLUSION: Body mass index was not a determinant of body image dissatisfaction, whereas the sum of five skinfolds proved to be a significant predictor of this disorder, irrespective of sex.

Keywords: Body image, nutritional status, students, self-image.

Introduction

Body image perception can be defined as an illustration of what is inside an individual's mind in terms of body size, image and shape, and also about feelings related to these characteristics, as well as to the parts that compose it.¹ Thus, it can be understood as a phenomenon of affective, cognitive, perceptive and behavioral components.^2,3

The subjective component of body image refers to a person's dissatisfaction with her body size and specific body parts. Therefore, such dissatisfaction comprehends several factors that are interrelated, such as perception of parents' and friends' expectations to be thinner,⁴ geographical location of place of residence (large urban centers or smaller towns),⁵ depression⁶ and health behaviors (self-esteem, eating behavior, use of steroids and exercise dependence),^3,6 wrong perception of body weight,⁷ age,⁶ personal reasons for trying to lose weight (appearance, health or esthetics)⁸ and gender.^9,10

While some studies have suggested that people with weight excess are less satisfied with body image,^10,11 others have shown that even in those with proper body mass, prevalence of dissatisfaction is quite high,⁴ i.e., the relationship between nutritional status and body image dissatisfaction remains unsolved. Studies aimed at investigating this relationship only used body mass index (BMI) as a measure of nutritional status.^4,6,10-12

The main explanation for such disagreement as to nutritional status is that there seems to be an exaggerated concern about body esthetics, and beauty patterns do not usually correspond to patterns considered adequate for health. However, the fact that BMI is not an accurate index of body fat can be considered as another possible cause.^13,14 In this sense, it is necessary to investigate the association between body image dissatisfaction and other nutritional status measures, such as sum of skinfold thickness, which not only maintains practicability and low cost, but also better reflects body fat.¹⁵

Hence, the objectives of this study were a) to investigate the association between body image dissatisfaction and two nutritional status indexes; b) to identify the best predictor of body image dissatisfaction in Brazilian university students.

Methods

It is a cross-sectional study of university students enrolled at Physical Education (offered as an optional discipline for students of all courses) at a public university in Florianópolis, State of Santa Catarina, Brazil. Firstly, all professors were invited to make their students available for researchers and allocate respective schedules for data collection. Next, the students in the classes in which the professors agreed to participate in the study were informed in advance about the purposes of the study and the dates for data collection. In each participating class, all students interested in participating were included in the sample and submitted to evaluation.

According to information obtained from the academic department, 1,034 students were regularly enrolled in that discipline. A total of 263 university students (25.4%) agreed to participate in the study (133 men and 130 women). After excluding the individuals who did not provide information about body image (five men and two women), the data from 256 participants were analyzed, equally distributed between genders. All participants were invited to complete a questionnaire that included specific information about gender, age and body image perception.

The study was approved by the Research Ethics Committee of Universidade Federal de Santa Catarina. Data were collected after the individuals signed a consent form. Secrecy of individual information was ensured.

The information regarding perceived body image was obtained using the Figure Rating Scale proposed by Stunkard et al.¹⁶ To collect data, the individuals were shown a group of silhouettes and then asked the following questions: Which silhouette best represents your current physical appearance? Which silhouette would you like to have? The examiner did not provide any opinion as to choice of silhouettes. The investigation of body image dissatisfaction was performed using disagreement between current silhouette and ideal silhouette to classify individuals as satisfied or dissatisfied.

Anthropometric data (body mass, stature and skinfold thickness) were measured by two experienced examiners, in accordance with standard procedures.^17,18 Measurement of body mass was performed using a digital scale (Plena), with 150 kg capacity and 0.1 kg sensitivity, with automatic shut-off and automatic calibration at every measurement.

A height flexible steel tape measure attached on the wall was used to measure stature; its verticality was verified using a plumb line. The individual was placed at this site, standing straight and with his feet and ankles together, buttocks and head against the wall, with reference to the Frankfurt plane. Values were recorded with 0.1-cm accuracy.

A Cescorf skinfold compass with 0.1-mm sensitivity was used to measure skinfold thickness (subscapular, triceps, biceps, suprailiac and calf).

Nutritional status was assessed using the BMI - body mass (kg) / height (m²) - and the sum of five skinfold thickness sites (Σ5ST). Cut-off points according to widely accepted recommendations in the literature were defined to investigate nutritional status: inadequate BMI (< 18.5 or ≥ 25.0 kg/m²)¹⁹ and inadequate Σ5ST (≤ 30 or ≥ 62 and ≤ 43 or ≥ 76 mm, for men and women, respectively).²⁰

Standard deviation, means and proportions were used in the descriptive analysis of variables. Percentage frequency tables were created to find the proportion of university students below or above proper cut-off points for BMI and Σ5ST. The significance test for differences between proportions was used to compare two proportions. The chi-square test was used to verify differences in frequency between variables. The association between nutritional status measurements and body image dissatisfaction was analyzed by logistic regression. Two models, a simple one and a multiple (gender-controlled) one, were tested. Significance level was set at 5% for all analyses. Statistical analysis was performed using SPSS^® version 10.0 and MedCalc version 9.3.3.0.

Results

Data in Table 1 present age, mean and standard deviation, anthropometric measures, and current and ideal body image perception in the population studied.

The results showed that most individuals (78.8%) were dissatisfied with their own body image. In addition, 49.2% of individuals wanted to reduce silhouette size, while 26.6% wanted to increase it. Distribution of university students by gender, according to body image dissatisfaction, is presented in Figure 1.

Figure 1 - Click to enlarge

The results of Figure 1A showed that, when analyzed dichotomously, there was no statistical difference between men and women as to prevalence of individuals dissatisfied with body image. However, when the group of dissatisfied individuals was divided according to desire to change silhouette size, chi-square showed a greater proportion in the female gender (p < 0.001) for the desire of reducing body dimensions, while in the male gender there was greater desire to increase them (p < 0.001) (Figure 1B).

Figure 2 shows the proportion of individuals classified according to nutritional status based on cut-off points for BMI and Σ5ST. According to the data in Figure 2A, 83.2% of the individuals were classified as healthy based on BMI, while only 34% were in that condition based on Σ5ST. Difference in proportions was statistically different (p < 0.05). When the analysis was performed non-dichotomously (Figure 1B), Σ5ST indicated higher proportion of overweight individuals (p < 0.05).

Figure 2 - Click to enlarge

Figure 3 shows the proportion of individuals, according to gender, who were below or above the cut-off points considered as inadequate for health.

Figure 3 - Click to enlarge

There was a significant correlation between BMI and Σ5ST for men (r = 0.692; p < 0.001) and women (r = 0.761; p < 0.001). The proportion test showed significant difference (p < 0.05) for Σ5ST in the distribution of nutritional status, and women had higher prevalence of nutritional inadequacy. The same was not observed for BMI (p > 0.05) (Figure 3A). However, when the inadequate group was transformed into two categories (underweight and overweight), a higher number of women were classified as low weight by BMI (p < 0.05), while Σ5ST showed the opposite: higher number of women who had overweight (p < 0.05) (Figure 3B).

Table 2 shows the association between body image dissatisfaction and nutritional inadequacy according to both anthropometric indexes. Odds ratio (OR) did not show any difference in frequency of body image dissatisfaction between genders (CI95% 0.40-1.26). Crude OR showed that inadequate BMI (< 18.5 or ≥ 25.0 kg/m²) was associated with body image dissatisfaction (CI95% 1.04-7.38), and the same occurred with Σ5ST (CI95% 1.25-4.05). However, only inadequate Σ5ST was a significant predictor of body image dissatisfaction in university students who showed nutritional inadequacy in the multiple model adjusted by gender. According to this index, they have a 2.5-fold chance of being dissatisfied with their own body (CI95% 1.36-4.80) than those who had body fat within proper health levels.

Discussion

According to the findings in the literature, no study has been found considering more than one anthropometric index to investigate the association between body image and nutritional status, as well as to identify which anthropometric index is the best predictor for this outcome. Hence, the present study was the first to deal with the association between two nutritional status indexes and body image dissatisfaction.

This study collected data from 256 university students enrolled at Physical Education at a federal university in Florianópolis, Brazil, which corresponds to 24.8% of the total population.

The body silhouette method can be easily and quickly applied and has shown good reliability. It has been widely used over the past years, including in population studies^4,12,21-23 and in university students.¹¹ However, the main limitations regarding silhouette drawings are directly associated with bidimensional linear forms, which may imply flaws in total body representation, in distribution of fat mass and in other aspects of body composition that are important in the formation of a body image.^8,24 In addition, it is based on a biotype that cannot be the same of the Brazilian population.

The results showed that a large number of university students are dissatisfied with their own body image. In studies performed in Brazil, the prevalence of body image dissatisfaction was similar to that of the present study, with prevalence rates of 82% in school students⁴ and 76 and 82% in physically active women and men, respectively.⁸

Women in general want to reduce their body silhouette size, while the desire of having a stronger and more voluminous body is predominant in men. These results are similar to those by Damasceno et al.,⁸ who demonstrated the same tendency in a study performed in a sample of 186 individuals who regularly took walks in a city in the State of Minas Gerais, Brazil.

This difference in preferences of body silhouettes between men and women can be explained by the fact that women overestimate body image and men underestimate it.^{11,12,22,25-27}

An important finding of the present study was the significant difference between both indexes (BMI and Σ5ST) in the classification of nutritional status. Pearson's test showed moderate to high correlation between both anthropometric indexes in men and women. The results also showed that, while the BMI classified most university students as adequate, Σ5ST showed that more than half of them were in a status of nutritional inadequacy. Such inconsistency was also seen in an investigation performed in adolescents, which showed that only 49% of girls and 57% of boys were concomitantly classified by BMI and sum of skinfold thickness.¹⁵

Although the results of this study had shown higher prevalence of body image dissatisfaction in men, regression analysis showed that gender was not a significant predictor of body image dissatisfaction .

Over the past years, several cross-sectional studies have been performed with the aim of investigating the relationship between body image dissatisfaction and nutritional status. However, investigations have used BMI as the standard measurement of nutritional status for this purpose,^4,9-12 and results have not been consistent.

In univariate analyses, there was significant association between BMI and body image dissatisfaction. Individuals with nutritional inadequacy had approximately three times more chances of having body image dissatisfaction in relation to adequate individuals. The same occurred to the other index (Σ5ST). Nevertheless, the association between BMI and outcome disappeared when the variables (BMI and Σ5ST) were adjusted in the gender-controlled multiple model, whereas the association of Σ5ST was maintained (Table 2). These results suggest that Σ5ST was the index with the best predictive power of body image dissatisfaction in university students compared with BMI.

The findings regarding BMI suggest that this index is not always equivalent to how individuals perceive their bodies. Therefore, there is the possibility of an individual having adequate BMI and wishing to reduce or increase silhouette size, enhancing his/her body image dissatisfaction. In this sense, it seems that the reason of not having any association between BMI and body image dissatisfaction was that most individuals, independently of BMI classification (adequate or inadequate), were dissatisfied with their body size and shape.

Thus, two possible explanations for Σ5ST having higher prediction power of body image dissatisfaction than BMI can be assumed: 1) since Σ5ST classified most university students as having excess of body fat, body image dissatisfaction would depend more on amount of subcutaneous adipose tissue than on amount of total body mass; 2) Σ5ST, because it is a result of subcutaneous body fat measures, is an index of nutritional status and body composition, different from BMI, which only verifies nutritional status.

It is worth stressing that, opposed to some studies^10,11 suggesting a relationship between BMI and body image dissatisfaction, the results of this study showed that BMI was not a determinant of outcome.

This study has limitations inherent to cross-sectional studies, i.e., it estimates the relationships between variables at a single moment, which prevents identification of cause and effect relationships. It is also important to stress that, in the present study, overweight and obesity were grouped along with low weight, forming the category inadequate BMI. The same criterion was adopted for Σ5ST. Thus, the way variables were dichotomized may not have been the best to show an association between nutritional status and body image dissatisfaction.

In summary, body image dissatisfaction was a highly frequent phenomenon in university students of both genders. For this reason, it should be considered as a serious public health problem, since it can partly condition unhealthy behavioral attitudes and conducts, such as anorexia, bulimia, dysmorphia, and acceptance of misguided diets.³

According to the analysis performed in this study, the data suggest that, regardless of gender, Σ5ST is a strong predictor of body image dissatisfaction in university students, while BMI does not seem to be a significant determinant of this outcome. However, other behavioral factors, especially those related to esthetic patterns, should be investigated.

Considering that this study was cross-sectional and restricted to university students, further studies with nutritional intervention and/or physical exercise are needed, with the aim of identifying their impact on body composition and, thus, on self-esteem and levels of body image satisfaction. Other comparative analyses, considering different social and ethnic groups, are needed for a better understanding of the relationship between nutritional status and body image.

Finally, it is worth stressing that, as a form of providing feedback to the participants of the study, a report containing all information and interpretations regarding body composition and respective recommendations was printed and delivered to all participants immediately after data collection.

References

• 1. Slade PD. Body image in anorexia nervosa. Br J Psychiatry Suppl. 1988;2:20-2.
• 2. Sepúlveda AR, Botella J, León JA. Body-image disturbance in eating disorders: A meta-analysis. Psychology in Spain. 2002;6:83-95.
• 3. McCabe MP, Ricciardelli LA. Body image dissatisfaction among males across the lifespan: a review of past literature. J Psychosom Res. 2004;56:675-85.
• 4. Pinheiro AP, Giugliani ER. Body dissatisfaction in Brazilian schoolchildren: prevalence and associated factors. Rev Saude Publica. 2006;40:489-96.
• 5. Hayashi F, Takimoto H, Yoshita K, Yoshiike N. Perceived body size and desire for thinness of young Japanese women: a population-based survey. Br J Nutr. 2006;96:1154-62.
• 6. Hrabosky JI, Grilo CM. Body image and eating disordered behavior in a community sample of Black and Hispanic women. Eat Behav. 2007;8:106-14.
• 7. Dionne MM, Davis C. Body image variability: the influence of body-composition information and neuroticism on young women's body dissatisfaction. Body Image. 2004;1:335-49.
• 8. O'Brien K, Venn BJ, Perry T, Green TJ, Aitken W, Bradshaw A, et al. Reasons for wanting to lose weight: different strokes for different folks. Eat Behav. 2007;8:132-35.
• 9. Damasceno VO, Lima JRP, Vianna JM, Vianna VRA, Novaes JS. Tipo físico ideal e satisfação com a imagem corporal de praticantes de caminhada. Rev Bras Med Esporte. 2005;11:181-86.
• 10. Conti MA, Frutuoso MFP, Gambardella AMD. Excesso de peso e insatisfação corporal em adolescentes. Rev Nutr. 2005;18:491-97.
• 11. Kakeshita IS, Almeida SS. Relação entre índice de massa corporal e a percepção da auto-imagem em universitários. Rev Saude Publica. 2006;40:497-504.
• 12. Branco LM, Hilário MOE, Cintra IP. Percepção e satisfação corporal em adolescentes e a relação com seu estado nutricional. Rev Psiquiatr Clín. 2006;33:292-6.
• 13. Acuña K, Cruz T. Avaliação do estado nutricional de adultos e idosos e situação nutricional da população brasileira. Arq Bras Endocrinol Metab. 2004;48:345-61.
• 14. Anjos LA. Índice de massa corporal (massa corporal.estatura^-2) como indicador do estado nutricional de adultos: revisão da literatura. Rev Saude Publica. 1992;26:431-6.
• 15. Glaner MF. Índice de massa corporal como indicativo da gordura corporal comparado às dobras cutâneas. Rev Bras Med Esporte. 2005;11:243-6.
• 16. Stunkard AJ, Sorenson T, Schlusinger F. Use of the Danish adoption register for the study of obesity and thinness. In: Kety SS, Rowland LP, Sidman RL, Matthysse SW, editors. The genetics of neurological and psychiatric disorders. New York: Raven; 1983. p. 115-20.
• 17. Alvarez BR, Pavan AL. Alturas e comprimentos. In: Petroski EL, editor. Antropometria: técnicas e padronizações. 3 ed. Blumenau: Nova Letra; 2007. p. 31-44.
• 18. Benedetti TRB, Pinho RA, Ramos VM. Dobras cutâneas. In: Petroski EL, editor. Antropometria: técnicas e padronizações. 3 ed. Blumenau: Nova Letra; 2007. p. 45-56.
• ¹⁹
  World Health Organization. Obesity: preventing and managing the global epidemic. Geneva: WHO; 1998.
• ²⁰
  Canadian Society for Exercise Physiology (CSEF). The Canadian physical activity, fitness and lifestyle appraisal: CSEP's guide to health active living. 2nd ed. Ottawa: CSEF; 2003.
• 21. Sánchez-Villegas A, Madrigal H, Martínez-González MA, Kearney J, Gibney MJ, Irala J, et al. Perception of body image as indicator of weight status in the European Union. J Hum Nutr Diet. 2001;14:93-102.
• 22. Madrigal H, Sánchez-Villegas A, Martinez-González MA, Kearney J, Gibney MJ, Irala J, et al. Underestimation of body mass index through perceived body image as compared to self-reported body mass index in the European Union. Public Health. 2000;114:468-73.
• 23. Madrigal Fritsch H, de Irala Estévez J, Martínez González MA, Kearney J, Gibney M, Martínez Hernández JA. Percepción de la imagen corporal como aproximación cualitativa al estado de nutrición. Salud Pública Méx. 1999;41:479-86.
• 24. Kay S. The psychological and anthropometric in body image. In: Norton K, Olds T, editors. Anthropometrica. Sydney: University of New South Wales Press; 1996. p. 217-38.
• 25. Atalah E, Urteaga C, Rebolledo A. Autopercepción del estado nutricional en adultos de Santiago. Rev Med Chile. 2004;132:1383-8.
• 26. Veggi AB, Lopes CS, Faerstein E, Sichieri R. Índice de massa corporal, percepção do peso corporal e transtornos mentais comuns entre funcionários de uma universidade no Rio de Janeiro. Rev Bras Psiquiatr. 2004;26:242-7.
• 27. Tanaka S, Itoh Y, Hattori K. Relationship of body composition to body-fatness estimation in Japanese university students. Obes Res. 2002;10:590-6.

Publication Dates

• Publication in this collection
  01 Dec 2008
• Date of issue
  Apr 2008

History

• Accepted
  05 Dec 2007
• Received
  02 Oct 2007