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Does nutritional status interfere with adolescents' body image perception?
Eating Behaviors 15 (2014) 509–512
Contents lists available at ScienceDirect
Eating Behaviors
Does nutritional status interfere with adolescents' body image perception? Karla L. Mendonça ⁎, Ana L.L. Sousa, Carolina S. Carneiro, Flávia M.N. Nascente, Thaís I.R. Póvoa, Weimar K.S.B. Souza, Thiago S.V. Jardim, Paulo C.B.V. Jardim Liga de Hipertensão Arterial, Universidade Federal de Goiás, Brazil
a r t i c l e
i n f o
Article history: Received 6 February 2014 Received in revised form 7 April 2014 Accepted 12 June 2014 Available online 21 June 2014 Keywords: Adolescent Nutritional status Body mass index Body image
a b s t r a c t Adolescents' body image (BI) may not match their nutritional status. This study selected representative sample of healthy adolescents aged between 12 and 18 from public and private schools. Anthropometric measures were performed in order to calculate the body mass index (BMI) percentile. The silhouette scale proposed by Childress was used to evaluate BI, making it possible to assess BI satisfaction and BI distortion. The sample was composed of 1168 adolescents with a mean age of 14.7 years; 52.9% were female, 50.9% were fair-skinned, 62.4% had consumed or still consume alcohol and 67% attended public school. Male adolescents presented more overweight and obesity (28.4%) (p b 0.05) than the female (17.1%). It was observed that 69.4% were dissatisfied with BI, 91.1% of the obese and 69.8% of those with overweight wished to lose body weight and 82.5% of those underweight wished to gain body weight. BI distortion was identified, since 35% of the adolescents who were underweight did not regard themselves thin, 39.1% of the overweight individuals and 62.1% of the obese did not see themselves in their adequate classifications. Adolescents with overweight/obesity were those who presented higher dissatisfaction with BI, mainly the females. Male individuals presented a greater wish of gaining weight. BI distortion was present in adolescents of all classes of BMI percentile. © 2014 Elsevier Ltd. All rights reserved.
1. Introduction Increased sedentariness and poor eating are directly related to the population's prevalence of overweight and obesity, which reflects on the occurrence of non-communicable chronic diseases (Vinholes, Assunção, & Neutzling, 2009). Adolescents are more exposed to adverse physical and mental health effects minimizing the opportunity of adopting a healthier lifestyle (Silva & Lopes, 2008). Adoption of a sedentary lifestyle, increase of excess weight prevalence and excessive thinness may be related to a greater dissatisfaction with body image (BI) (Kakeshita & Almeida, 2006; Conti & Latorre, 2009) Adolescents regard self-perception and BI satisfaction as important self-acceptance factors (Brazil. National Survey of School Health, 2009). When the adolescent's perception of their body is not in accordance with their ideal image, they may have inadequate attitudes which may impair their development and growth.
⁎ Corresponding author at: Rua 24, número 245, Edifício Miguel Jorge Azzi, apartamento 904, Setor Central, CEP: 74030-060 Goiânia, GO, Brazil. Tel.: +55 62 8114 0292; fax: +55 62 3269 8433. E-mail address: klmfi[email protected] (K.L. Mendonça).
http://dx.doi.org/10.1016/j.eatbeh.2014.06.011 1471-0153/© 2014 Elsevier Ltd. All rights reserved.
Some adolescents, even with adequate weight or underweight, feel obese and are concerned about weight and appearance. This is denominated BI distortion and it is related to eating disorders and to obesity, which may cause low self-esteem and high levels of body dissatisfaction (Anton, Perri, & Riley, 2000; Conti, Frutuoso, & Gambardella, 2005). It is possible to find situations of body dissatisfaction in which the adolescent's perception of their body is not in accordance with what they idealize and the perception of their biotype is different from reality (Brazil. National Survey of School Health, 2009; Conti et al., 2005). The objective of this study was to identify the influence of BMI percentile on BI perception in teenage students of public and private schools of a large city. 2. Material and methods Descriptive cross-sectional study of a representative sample of male and female healthy adolescents aged between 12 and 18, enrolled in public and private schools, was conducted. Physical disability which did not allow anthropometric evaluation, pregnancy, chronic diseases and the use of medication were the exclusion criteria. This study was part of a project originally entitled: “Blood Pressure Home Measurement and its correlation with left ventricular mass index and insulin resistance
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K.L. Mendonça et al. / Eating Behaviors 15 (2014) 509–512
performed in order to identify BI perception distortion (Laus, Costa, & Almeida, 2009). Data analysis was performed with software SPSS Statistics version 20 and by software Open Epi. Kolmogorov–Smirnov's test was utilized for the distribution analysis, Wilcoxon's test to compare both related samples, Pearson's Chi-square was done to calculate categorical variables, and when necessary, Fisher's exact test. For the agreement analysis of measures taken among observers considering the ordinal scale, Kendall's Tau was utilized. It was considered the significance level of 5% and the confidence interval of 95%.
in adolescents with masked and white coat hypertension”—“Projeto CorAdo” (Coração de Adolescente—Adolescent's heart), approved by the institution's ethics committee and granted by CNPq, process number 477626/2009-2. The sample calculation was performed regarding the fact that the city has 125,525 inhabitants aged between 12 and 18 (IBGE, 2009). For the present study, it was calculated a sample of 306 adolescents, for an obesity prevalence of 3.5% (Ramos & Barros Filho, 2003), confidence interval of 95% and absolute precision of 2%. However, all adolescents who participated in the original project were analyzed. The schools were selected and 26 schools participated. Students were randomly selected and all of those who met the inclusion criteria and signed the Acceptance Term (AT) took part. Collection period was between October 2010 and November 2011. A duly trained team went to the schools and upon arrival applied the AT and the questionnaire to the students. Weight and height were measured, according to the methods described by Lohman, Roche, & Martorell (1988)); the BMI percentile was calculated, based on the new curves of the World Health Organization (WHO) (OMS, 2007). BI perception was evaluated through the application of the scale proposed by Childress, Brewerton, Hodges, & Jarrel (1993), which was based on the scale models developed by Stunkard, Sorenson, & Schlusinger (1983) to allow the use on adolescents. The scale is formed by a group of drawings, containing eight figures of female and male silhouettes, which represent human figures with variations, in ascending order, of body size. The group of silhouettes was shown to adolescents. Each drawing contained a numeration that corresponds to a class of BMI percentile, which was calculated by the Brazilian website created by the Health Ministry, that follows the WHO criteria, being numerations 1 and 2 = below the weight (W b 3); 3 and 4 = healthy (W ≥ 3 and b 85); 5 and 6 = overweight (W ≥ 85 and b 97); 7 and 8 = obesity (W ≥ 97) (Adami, Frainer, Santos, Fernandes, & De Oliveira, 2008; Almeida, Santos, Pasian, & Loureiro, 2005; Brasil. Cálculo de IMC Infantil, 2013; Gomes, Anjos, & Vasconcellos, 2010). In order to evaluate BI, perceived body silhouette was subtracted from desired body silhouette identified by the scale numbers (Anton et al., 2000; Brazil. National Survey of School Health, 2009; Conti & Latorre, 2009; Conti et al., 2005; IBGE, 2009; Kakeshita & Almeida, 2006; Silva & Lopes, 2008; Vinholes et al., 2009). If the variation was equal to zero, the adolescent was classified as satisfied; if it was different from zero, the adolescent was classified as dissatisfied. A positive difference indicated dissatisfaction with the desire of reducing the silhouette, and, when negative, dissatisfaction with the desire of increasing the silhouette. The comparison between the calculated BMI percentile and the self-reported BMI percentile was
3. Results Sample was formed by 1168 adolescents, being 67% enrolled in public schools and 33% in private schools. Mean (±SD) age was 14.7 years (±1.6), and the predominant gender was female (52.9%). Fair-skin was identified in 50.9%, the consumption of alcohol self-reported by 62.4% and 1.2% claimed to be smokers. It was observed that 3.4% of the sample (n = 40) was underweight, 7.7% (n = 90) was obese and 14.7% (n = 172) was overweight, which demonstrated a prevalence of 22.4% (n = 262) of excess weight. Nutritional classification identified more male adolescents overweight, 18.9% (n = 104), and obese, 9.5% (n = 52), than females overweight, 11% (n = 68), and obesity, 6.1% (n = 38) (p b 0.05). The evaluation according to age demonstrated that obesity was more present among the youngest individuals (p b 0.05), and that the oldest adolescents were eutrophic (p b 0.05). Higher frequency of eutrophic adolescents was observed in public schools, whereas more overweight and obese students were in private schools (p b 0.05). Regarding BI perception, it was observed that 811 adolescents (69.4%) were dissatisfied with their body image, 30% wished to gain weight and 39.4% would like to lose weight. It was verified that 37.6% of the male adolescents were dissatisfied and wished to gain weight, whereas 46.4% of the female were also dissatisfied and wished to lose weight (p b 0.05). The youngest adolescents were the ones with greater dissatisfaction and wished to reduce their body weight (p b 0.05). It was observed that the public ones had more adolescents dissatisfied wishing to gain body weight (p b 0.05). The comparison between nutritional evaluation and BI perception identified that among those underweight, 82.5% (n = 33) would like to gain weight, which demonstrated the expected perception. Among those overweight, 69.8% (n = 120) wished to lose weight. Among the obese, 91.1% (n = 82) would like to lose weight, which also demonstrated an adequate perception. Nevertheless 5.1% of the total sample reported a desire to maintain or even increase their weight (Table 1).
Table 1 Distribution of frequency and percentage of BMI percentile classification by body image satisfaction. Goiânia—GO, Brazil, 2012. (n = 1168). Percentile classification BI perception
Dissatisfied—gain Satisfied Dissatisfied—lose
Underweight (a)
Eutrophic (b)
Overweight (c)
Obesity (d)
p*
n
%
n
%
n
%
n
%
(a) and (b)
(b) and (c)
(b) and (d)
33 6 1
82.5 15.0 2.5
310 298 258
35.8 34.4 29.8
6 46 120
3.5 26.7 69.8
1 7 82
1.1 7.8 91.1
b0.001 0.012 0.183
b0.001 0.059 b0.001
0.032 b0.001 b0.001
⁎Classification according to WHO percentile. Fisher's exact test. Most studied adolescents presented BI distortion, 39.1% of those overweight did not regard themselves overweight; moreover, 62.1% of those obese believed that they were eutrophic or only overweight. There was a moderate level of agreement between measured BMI (gold standard) and perceived BMI (τ − b of Kendall = 0.538). Among those evaluated as obese, only 37.9% (n = 33) classified themselves in this condition (Table 2).
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Table 2 Distribution of frequency and percentage of perceived BMI classification (indicated by the adolescent) and measured BMI. Goiânia—GO, Brazil, 2012. (n = 1168). Measure BMI—WHO percentile classification Perceived BMI
Underweight Eutrophic Overweight Obese
Underweight
Eutrophic
Overweight
Obese
n
%
n
%
n
%
n
%
26 13 1 0
65.0 32.5 2.5 0.0
141 567 146 2
16.5 66.2 17.1 0.2
2 53 103 11
1.2 31.4 60.9 6.5
0 2 52 33
0.0 2.3 59.8 37.9
4. Discussion Most adolescents evaluated in this study were eutrophic. The comparison with some studies showed variations, being found lower overweight/obesity percentage in some studies (Araújo, Dumith, Menezes, & Hallal, 2010; Martins, Pelegrini, Matheus, & Petroski, 2010) and higher percentage in others (Kunkel, Oliveira, & Peres, 2009). In the gender-related nutritional evaluation, male adolescents were more overweight, similar to the studies performed in Brazilian southern cities (Araújo et al., 2010; Kunkel et al., 2009; Vergilio & Gravena, 2011). It was noted that the youngest individuals presented more overweight, similar with other studies (Silva & Lopes, 2008). The present study revealed that overweight and obesity in adolescents were more frequent in private schools, similar to the findings of a study performed in João Pessoa (Silva & Lopes, 2008) and different from a study in Florianópolis (Alves, Vasconcelos, Calvo, & Neves, 2008) which showed more obese adolescents in public schools and a higher number of overweight in private schools. This study found that a high percentage of adolescents dissatisfied with their BI, which is in accordance with the data obtained by Triches and Giugliane (Triches & Giugliane, 2007) and different from those verified by Sonneville and Petroski (Petroski, Pelegrini, & Glaner, 2012; Sonneville et al., 2012). Similar to other studies, most females would like to lose weight, whereas males wished to increase theirs (Adami et al., 2008; Conti & Latorre, 2009; Petroski, Pelegrini, & Glaner, 2009; Petroski et al., 2012; Triches & Giugliane, 2007). This demonstrates a tendency in women who believe that their ideal weight should be reduced, whereas boys think that their ideal weight should be higher and burlier. In accordance with a study by Petroski et al. (2009), younger adolescents wish to reduce their weight. Those from public schools wish to gain weight, which is similar to the study by Fernandes et al. (2007). This BI dissatisfaction is quite present and these results corroborate the pressured represented by body models imposed by society, unattainable by most (Dunker, Fernandes, & Carreira, 2009; Kakeshita & Almeida, 2006). A large part of the adolescents who presented BI distortion was obese, since most of them believe that they are only overweight or even eutrophic, as stated in the study of Vergilio and Gravena (Vergilio & Gravena, 2011) accomplished on adolescents using a questionnaire that investigated BI disturbances. This fact probably occurs due to the fear of self-assertion (Dunker et al., 2009; Kakeshita & Almeida, 2006). It was also verified that, despite having an adequate weight, adolescents presented dissatisfaction, since they are greatly influenced by the media and society in general, which determines an excessively thin female beauty pattern and a male pattern that worship a built body (Andrade & Santos, 2009; Goetz, Camargo, Bertoldo, & Justo, 2008; Vergilio & Gravena, 2011). The population, in general, demonstrates a strong attitude against weight excess, which may be manifested by discriminatory behavior towards obesity. A study performed in Minneapolis (EUA) (Cossrow, Jeffery, & McGuire, 2001) stressed that many people are aware of this fact which shows that, in practically all aspects of life (among family, friends, unknown people, health professionals and potential employers),
obese people face the risk of receiving negative treatment (Cossrow et al., 2001). The vast majority also presents BI distortion, once they perceive themselves differently from reality either underestimating or overestimating their actual status. It was observed that most obese adolescents do not regard themselves as obese; they believe they are only overweight or even eutrophic. Through this study it was possible to verify how much sociocultural and media influences interfere with the weight acceptance or not of an adolescent. This demonstrates the importance of not creating standardized body models for men and for women, so that the teenage population can grow up without the pressure of having the perfect body and thus have better self-esteem to face the possible issues concerning their body weight. This study had some limitations; the first was the fact of including adolescents of only a determined age. This occurred due to the existence of questionnaires and instruments validated only for this age range. On the other hand, it was possible to accomplish the investigation in a stratified manner according to age and gender which was representative to this study. The second was regarding the BI scale. It presented similar figures that varied from thinner to more overweight silhouettes. These figures, when observed individually, could have confused the adolescent while selecting their desired and perceived BI. In order to reduce this risk, the scale was shown as whole, which eased the identification for the adolescent. A very positive point was the fact that the study was conducted since its beginning by the same team, previously trained, being the anthropometric measures always taken by the same person, which certainly allowed the obtaining of more reliable results (Table 2). Role of funding sources This project was part of a matrix project that received funding from the National Council for Scientific and Technological Development (CNPq) and the corresponding author received a scholarship for the Coordination of Improvement of Higher Education Personnel (CAPES). The funding source has not developed any role during the execution of the research.
Contributors The corresponding author (Karla Lorena Mendonça) was part of all stages of the project including design, data collection, search for theoretical reference, data analysis, writing and revision of the manuscript. Ana Luiza Lima Sousa worked in project design, analysis of data and contributed to review and have approved the final manuscript. Carolina de Sousa Carneiro worked during collection, data analysis and contributed to review and have approved the final manuscript. Flavia Miquetichuc Nogueira Nascente worked during collection, data analysis and contributed to review and have approved the final manuscript. Thais Inácio Rolim Póvoa worked during collection, data analysis and review of the manuscript. Weimar Kunz Sebba Barroso de Souza worked in project design and contributed to review and have approved the final manuscript. Thiago de Souza Veiga Jardim worked in project design, data analysis and contributed to review and have approved the final manuscript. Paulo César Brandão Veiga Jardim worked in project design, data collection and analysis, writing and contributed to review and have approved the final manuscript.
Conflict of interest All authors declare that they have no conflicts of interest.
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Acknowledgments To the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) (process number 477626/2009-2) and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for the project and research grants.
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Gomes, F. S., Anjos, L. A., & Vasconcellos, M. T. L. (2010). Anthropometry as a tool for assessing the nutritional status of adolescents. Revista de Nutrição, 23(4), 591–605. IBGE (2009). Estimativas elaboradas no âmbito do Projeto UNFPA/IBGE (BRA/4/P31A) População e Desenvolvimento. Coordenação de População e Indicadores Sociais. http://tabnet.datasus.gov.br/cgi/deftohtm.exe?ibge/cnv/popuf.def (cited 25-02-2013) Kakeshita, I. S., & Almeida, S. S. (2006). Relationship between body mass index and selfperception among university students. Revista de Saúde Pública, 40(3), 497–504. Kunkel, N., Oliveira, W. F., & Peres, M.A. (2009). Overweight and health-related quality of life in adolescents of Florianópolis, Southern Brazil. Revista de Saúde Pública, 43(2), 226–235. Laus, M. F., Costa, T. M. B., & Almeida, S. S. (2009). Adolescent's body image distortion: a comparison study between two instruments. Medicina (Ribeirão Preto), 42(3), 358–365. Lohman, T. G., Roche, A. F., & Martorell, R. (1988). Anthropometric standardisation reference manual. Human Kinetics Books. Martins, C. R., Pelegrini, A., Matheus, S.C., & Petroski, E. L. (2010). Body image dissatisfaction and its relationship with nutritional status, body fat, and anorexia and bulimia symptoms in adolescents. Revista de Psiquiatria, 32(1), 19–23. OMS (2007). Incorporação da Curvas de Crescimento da Organização Mundial da Saúde de 2006 e 2007 no SISVAN SISVAN. http://nutricao.saude.gov.br/sisvan.php?conteudo= curvas_cresc_oms (02.04.2013 9:23h]. 1–38) Petroski, E. L., Pelegrini, A., & Glaner, M. F. (2009). Body image dissatisfaction among rural and urban adolescents. Motricidade, 5(4), 13–25. Petroski, E. L., Pelegrini, A., & Glaner, M. F. (Apr 2012). Reasons and prevalence of body image dissatisfaction in adolescents. Ciência & Saúde Coletiva, 17(4), 1071–1077 (PubMed PMID: 22534860. Motivos e prevalencia de insatisfacao com a imagem corporal em adolescentes). Ramos, A.M. P. P., & Barros Filho, A. A. (2003). Prevalence of obesity in adolescents from Bragança Paulista and its relation to parental obesity. Arquivos Brasileiros de Endocrinologia & Metabologia, 47(6), 663–668. Silva, K. S., & Lopes, A. S. (2008). Excess weight, arterial pressure and physical activity in commuting to school: correlations. Arquivos Brasileiros de Cardiologia, 91(2), 93–101. Sonneville, K. R., Calzo, J. P., Horton, N. J., Haines, J., Austin, S. B., & Field, A. E. (2012). Body satisfaction, weight gain and binge eating among overweight adolescent girls. International Journal of Obesity, 36(7), 944–949. Stunkard, A. J., Sorenson, T., & Schlusinger, F. (1983). Use of the Danish Adoption Register for the study of obesity and thinness. In S. S. KETY, L. P. Rowland, R. L. Sidman, & S. W. Matthysse (Eds.), The genetics of neurological and psychiatric disorders (pp. 115–120). Triches, R. M., & Giugliane, E. R. J. (2007). Body dissatisfaction in school children from two cities in the south of Brazil. Revista de Nutrição Campinas, 20(2), 119–128. Vergilio, M. C. P., & Gravena, A. A. F. (2011). Anthropometric profile and anorexia symptomatology on public school adolescents. Acta Scientiarum Health Science, 33(2), 181–186. Vinholes, D. B., Assunção, M. C. F., & Neutzling, M. B. (2009). Frequency of healthy eating habits measured by the 10 steps to healthy eating score proposed by the Ministry of Health Pelotas, Rio Grande do Sul State, Brazil. Cadernos de Saude Publica/Ministerio da Saude, Fundacao Oswaldo Cruz, Escola Nacional de Saude Publica, 25(4), 791–799.
Contents lists available at ScienceDirect
Eating Behaviors
Does nutritional status interfere with adolescents' body image perception? Karla L. Mendonça ⁎, Ana L.L. Sousa, Carolina S. Carneiro, Flávia M.N. Nascente, Thaís I.R. Póvoa, Weimar K.S.B. Souza, Thiago S.V. Jardim, Paulo C.B.V. Jardim Liga de Hipertensão Arterial, Universidade Federal de Goiás, Brazil
a r t i c l e
i n f o
Article history: Received 6 February 2014 Received in revised form 7 April 2014 Accepted 12 June 2014 Available online 21 June 2014 Keywords: Adolescent Nutritional status Body mass index Body image
a b s t r a c t Adolescents' body image (BI) may not match their nutritional status. This study selected representative sample of healthy adolescents aged between 12 and 18 from public and private schools. Anthropometric measures were performed in order to calculate the body mass index (BMI) percentile. The silhouette scale proposed by Childress was used to evaluate BI, making it possible to assess BI satisfaction and BI distortion. The sample was composed of 1168 adolescents with a mean age of 14.7 years; 52.9% were female, 50.9% were fair-skinned, 62.4% had consumed or still consume alcohol and 67% attended public school. Male adolescents presented more overweight and obesity (28.4%) (p b 0.05) than the female (17.1%). It was observed that 69.4% were dissatisfied with BI, 91.1% of the obese and 69.8% of those with overweight wished to lose body weight and 82.5% of those underweight wished to gain body weight. BI distortion was identified, since 35% of the adolescents who were underweight did not regard themselves thin, 39.1% of the overweight individuals and 62.1% of the obese did not see themselves in their adequate classifications. Adolescents with overweight/obesity were those who presented higher dissatisfaction with BI, mainly the females. Male individuals presented a greater wish of gaining weight. BI distortion was present in adolescents of all classes of BMI percentile. © 2014 Elsevier Ltd. All rights reserved.
1. Introduction Increased sedentariness and poor eating are directly related to the population's prevalence of overweight and obesity, which reflects on the occurrence of non-communicable chronic diseases (Vinholes, Assunção, & Neutzling, 2009). Adolescents are more exposed to adverse physical and mental health effects minimizing the opportunity of adopting a healthier lifestyle (Silva & Lopes, 2008). Adoption of a sedentary lifestyle, increase of excess weight prevalence and excessive thinness may be related to a greater dissatisfaction with body image (BI) (Kakeshita & Almeida, 2006; Conti & Latorre, 2009) Adolescents regard self-perception and BI satisfaction as important self-acceptance factors (Brazil. National Survey of School Health, 2009). When the adolescent's perception of their body is not in accordance with their ideal image, they may have inadequate attitudes which may impair their development and growth.
⁎ Corresponding author at: Rua 24, número 245, Edifício Miguel Jorge Azzi, apartamento 904, Setor Central, CEP: 74030-060 Goiânia, GO, Brazil. Tel.: +55 62 8114 0292; fax: +55 62 3269 8433. E-mail address: klmfi[email protected] (K.L. Mendonça).
http://dx.doi.org/10.1016/j.eatbeh.2014.06.011 1471-0153/© 2014 Elsevier Ltd. All rights reserved.
Some adolescents, even with adequate weight or underweight, feel obese and are concerned about weight and appearance. This is denominated BI distortion and it is related to eating disorders and to obesity, which may cause low self-esteem and high levels of body dissatisfaction (Anton, Perri, & Riley, 2000; Conti, Frutuoso, & Gambardella, 2005). It is possible to find situations of body dissatisfaction in which the adolescent's perception of their body is not in accordance with what they idealize and the perception of their biotype is different from reality (Brazil. National Survey of School Health, 2009; Conti et al., 2005). The objective of this study was to identify the influence of BMI percentile on BI perception in teenage students of public and private schools of a large city. 2. Material and methods Descriptive cross-sectional study of a representative sample of male and female healthy adolescents aged between 12 and 18, enrolled in public and private schools, was conducted. Physical disability which did not allow anthropometric evaluation, pregnancy, chronic diseases and the use of medication were the exclusion criteria. This study was part of a project originally entitled: “Blood Pressure Home Measurement and its correlation with left ventricular mass index and insulin resistance
510
K.L. Mendonça et al. / Eating Behaviors 15 (2014) 509–512
performed in order to identify BI perception distortion (Laus, Costa, & Almeida, 2009). Data analysis was performed with software SPSS Statistics version 20 and by software Open Epi. Kolmogorov–Smirnov's test was utilized for the distribution analysis, Wilcoxon's test to compare both related samples, Pearson's Chi-square was done to calculate categorical variables, and when necessary, Fisher's exact test. For the agreement analysis of measures taken among observers considering the ordinal scale, Kendall's Tau was utilized. It was considered the significance level of 5% and the confidence interval of 95%.
in adolescents with masked and white coat hypertension”—“Projeto CorAdo” (Coração de Adolescente—Adolescent's heart), approved by the institution's ethics committee and granted by CNPq, process number 477626/2009-2. The sample calculation was performed regarding the fact that the city has 125,525 inhabitants aged between 12 and 18 (IBGE, 2009). For the present study, it was calculated a sample of 306 adolescents, for an obesity prevalence of 3.5% (Ramos & Barros Filho, 2003), confidence interval of 95% and absolute precision of 2%. However, all adolescents who participated in the original project were analyzed. The schools were selected and 26 schools participated. Students were randomly selected and all of those who met the inclusion criteria and signed the Acceptance Term (AT) took part. Collection period was between October 2010 and November 2011. A duly trained team went to the schools and upon arrival applied the AT and the questionnaire to the students. Weight and height were measured, according to the methods described by Lohman, Roche, & Martorell (1988)); the BMI percentile was calculated, based on the new curves of the World Health Organization (WHO) (OMS, 2007). BI perception was evaluated through the application of the scale proposed by Childress, Brewerton, Hodges, & Jarrel (1993), which was based on the scale models developed by Stunkard, Sorenson, & Schlusinger (1983) to allow the use on adolescents. The scale is formed by a group of drawings, containing eight figures of female and male silhouettes, which represent human figures with variations, in ascending order, of body size. The group of silhouettes was shown to adolescents. Each drawing contained a numeration that corresponds to a class of BMI percentile, which was calculated by the Brazilian website created by the Health Ministry, that follows the WHO criteria, being numerations 1 and 2 = below the weight (W b 3); 3 and 4 = healthy (W ≥ 3 and b 85); 5 and 6 = overweight (W ≥ 85 and b 97); 7 and 8 = obesity (W ≥ 97) (Adami, Frainer, Santos, Fernandes, & De Oliveira, 2008; Almeida, Santos, Pasian, & Loureiro, 2005; Brasil. Cálculo de IMC Infantil, 2013; Gomes, Anjos, & Vasconcellos, 2010). In order to evaluate BI, perceived body silhouette was subtracted from desired body silhouette identified by the scale numbers (Anton et al., 2000; Brazil. National Survey of School Health, 2009; Conti & Latorre, 2009; Conti et al., 2005; IBGE, 2009; Kakeshita & Almeida, 2006; Silva & Lopes, 2008; Vinholes et al., 2009). If the variation was equal to zero, the adolescent was classified as satisfied; if it was different from zero, the adolescent was classified as dissatisfied. A positive difference indicated dissatisfaction with the desire of reducing the silhouette, and, when negative, dissatisfaction with the desire of increasing the silhouette. The comparison between the calculated BMI percentile and the self-reported BMI percentile was
3. Results Sample was formed by 1168 adolescents, being 67% enrolled in public schools and 33% in private schools. Mean (±SD) age was 14.7 years (±1.6), and the predominant gender was female (52.9%). Fair-skin was identified in 50.9%, the consumption of alcohol self-reported by 62.4% and 1.2% claimed to be smokers. It was observed that 3.4% of the sample (n = 40) was underweight, 7.7% (n = 90) was obese and 14.7% (n = 172) was overweight, which demonstrated a prevalence of 22.4% (n = 262) of excess weight. Nutritional classification identified more male adolescents overweight, 18.9% (n = 104), and obese, 9.5% (n = 52), than females overweight, 11% (n = 68), and obesity, 6.1% (n = 38) (p b 0.05). The evaluation according to age demonstrated that obesity was more present among the youngest individuals (p b 0.05), and that the oldest adolescents were eutrophic (p b 0.05). Higher frequency of eutrophic adolescents was observed in public schools, whereas more overweight and obese students were in private schools (p b 0.05). Regarding BI perception, it was observed that 811 adolescents (69.4%) were dissatisfied with their body image, 30% wished to gain weight and 39.4% would like to lose weight. It was verified that 37.6% of the male adolescents were dissatisfied and wished to gain weight, whereas 46.4% of the female were also dissatisfied and wished to lose weight (p b 0.05). The youngest adolescents were the ones with greater dissatisfaction and wished to reduce their body weight (p b 0.05). It was observed that the public ones had more adolescents dissatisfied wishing to gain body weight (p b 0.05). The comparison between nutritional evaluation and BI perception identified that among those underweight, 82.5% (n = 33) would like to gain weight, which demonstrated the expected perception. Among those overweight, 69.8% (n = 120) wished to lose weight. Among the obese, 91.1% (n = 82) would like to lose weight, which also demonstrated an adequate perception. Nevertheless 5.1% of the total sample reported a desire to maintain or even increase their weight (Table 1).
Table 1 Distribution of frequency and percentage of BMI percentile classification by body image satisfaction. Goiânia—GO, Brazil, 2012. (n = 1168). Percentile classification BI perception
Dissatisfied—gain Satisfied Dissatisfied—lose
Underweight (a)
Eutrophic (b)
Overweight (c)
Obesity (d)
p*
n
%
n
%
n
%
n
%
(a) and (b)
(b) and (c)
(b) and (d)
33 6 1
82.5 15.0 2.5
310 298 258
35.8 34.4 29.8
6 46 120
3.5 26.7 69.8
1 7 82
1.1 7.8 91.1
b0.001 0.012 0.183
b0.001 0.059 b0.001
0.032 b0.001 b0.001
⁎Classification according to WHO percentile. Fisher's exact test. Most studied adolescents presented BI distortion, 39.1% of those overweight did not regard themselves overweight; moreover, 62.1% of those obese believed that they were eutrophic or only overweight. There was a moderate level of agreement between measured BMI (gold standard) and perceived BMI (τ − b of Kendall = 0.538). Among those evaluated as obese, only 37.9% (n = 33) classified themselves in this condition (Table 2).
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Table 2 Distribution of frequency and percentage of perceived BMI classification (indicated by the adolescent) and measured BMI. Goiânia—GO, Brazil, 2012. (n = 1168). Measure BMI—WHO percentile classification Perceived BMI
Underweight Eutrophic Overweight Obese
Underweight
Eutrophic
Overweight
Obese
n
%
n
%
n
%
n
%
26 13 1 0
65.0 32.5 2.5 0.0
141 567 146 2
16.5 66.2 17.1 0.2
2 53 103 11
1.2 31.4 60.9 6.5
0 2 52 33
0.0 2.3 59.8 37.9
4. Discussion Most adolescents evaluated in this study were eutrophic. The comparison with some studies showed variations, being found lower overweight/obesity percentage in some studies (Araújo, Dumith, Menezes, & Hallal, 2010; Martins, Pelegrini, Matheus, & Petroski, 2010) and higher percentage in others (Kunkel, Oliveira, & Peres, 2009). In the gender-related nutritional evaluation, male adolescents were more overweight, similar to the studies performed in Brazilian southern cities (Araújo et al., 2010; Kunkel et al., 2009; Vergilio & Gravena, 2011). It was noted that the youngest individuals presented more overweight, similar with other studies (Silva & Lopes, 2008). The present study revealed that overweight and obesity in adolescents were more frequent in private schools, similar to the findings of a study performed in João Pessoa (Silva & Lopes, 2008) and different from a study in Florianópolis (Alves, Vasconcelos, Calvo, & Neves, 2008) which showed more obese adolescents in public schools and a higher number of overweight in private schools. This study found that a high percentage of adolescents dissatisfied with their BI, which is in accordance with the data obtained by Triches and Giugliane (Triches & Giugliane, 2007) and different from those verified by Sonneville and Petroski (Petroski, Pelegrini, & Glaner, 2012; Sonneville et al., 2012). Similar to other studies, most females would like to lose weight, whereas males wished to increase theirs (Adami et al., 2008; Conti & Latorre, 2009; Petroski, Pelegrini, & Glaner, 2009; Petroski et al., 2012; Triches & Giugliane, 2007). This demonstrates a tendency in women who believe that their ideal weight should be reduced, whereas boys think that their ideal weight should be higher and burlier. In accordance with a study by Petroski et al. (2009), younger adolescents wish to reduce their weight. Those from public schools wish to gain weight, which is similar to the study by Fernandes et al. (2007). This BI dissatisfaction is quite present and these results corroborate the pressured represented by body models imposed by society, unattainable by most (Dunker, Fernandes, & Carreira, 2009; Kakeshita & Almeida, 2006). A large part of the adolescents who presented BI distortion was obese, since most of them believe that they are only overweight or even eutrophic, as stated in the study of Vergilio and Gravena (Vergilio & Gravena, 2011) accomplished on adolescents using a questionnaire that investigated BI disturbances. This fact probably occurs due to the fear of self-assertion (Dunker et al., 2009; Kakeshita & Almeida, 2006). It was also verified that, despite having an adequate weight, adolescents presented dissatisfaction, since they are greatly influenced by the media and society in general, which determines an excessively thin female beauty pattern and a male pattern that worship a built body (Andrade & Santos, 2009; Goetz, Camargo, Bertoldo, & Justo, 2008; Vergilio & Gravena, 2011). The population, in general, demonstrates a strong attitude against weight excess, which may be manifested by discriminatory behavior towards obesity. A study performed in Minneapolis (EUA) (Cossrow, Jeffery, & McGuire, 2001) stressed that many people are aware of this fact which shows that, in practically all aspects of life (among family, friends, unknown people, health professionals and potential employers),
obese people face the risk of receiving negative treatment (Cossrow et al., 2001). The vast majority also presents BI distortion, once they perceive themselves differently from reality either underestimating or overestimating their actual status. It was observed that most obese adolescents do not regard themselves as obese; they believe they are only overweight or even eutrophic. Through this study it was possible to verify how much sociocultural and media influences interfere with the weight acceptance or not of an adolescent. This demonstrates the importance of not creating standardized body models for men and for women, so that the teenage population can grow up without the pressure of having the perfect body and thus have better self-esteem to face the possible issues concerning their body weight. This study had some limitations; the first was the fact of including adolescents of only a determined age. This occurred due to the existence of questionnaires and instruments validated only for this age range. On the other hand, it was possible to accomplish the investigation in a stratified manner according to age and gender which was representative to this study. The second was regarding the BI scale. It presented similar figures that varied from thinner to more overweight silhouettes. These figures, when observed individually, could have confused the adolescent while selecting their desired and perceived BI. In order to reduce this risk, the scale was shown as whole, which eased the identification for the adolescent. A very positive point was the fact that the study was conducted since its beginning by the same team, previously trained, being the anthropometric measures always taken by the same person, which certainly allowed the obtaining of more reliable results (Table 2). Role of funding sources This project was part of a matrix project that received funding from the National Council for Scientific and Technological Development (CNPq) and the corresponding author received a scholarship for the Coordination of Improvement of Higher Education Personnel (CAPES). The funding source has not developed any role during the execution of the research.
Contributors The corresponding author (Karla Lorena Mendonça) was part of all stages of the project including design, data collection, search for theoretical reference, data analysis, writing and revision of the manuscript. Ana Luiza Lima Sousa worked in project design, analysis of data and contributed to review and have approved the final manuscript. Carolina de Sousa Carneiro worked during collection, data analysis and contributed to review and have approved the final manuscript. Flavia Miquetichuc Nogueira Nascente worked during collection, data analysis and contributed to review and have approved the final manuscript. Thais Inácio Rolim Póvoa worked during collection, data analysis and review of the manuscript. Weimar Kunz Sebba Barroso de Souza worked in project design and contributed to review and have approved the final manuscript. Thiago de Souza Veiga Jardim worked in project design, data analysis and contributed to review and have approved the final manuscript. Paulo César Brandão Veiga Jardim worked in project design, data collection and analysis, writing and contributed to review and have approved the final manuscript.
Conflict of interest All authors declare that they have no conflicts of interest.
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Acknowledgments To the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) (process number 477626/2009-2) and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for the project and research grants.
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