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Disordered eating behaviors in adolescents and adults living in the same household in metropolitan area of Rio de Janeiro, Brazil
Psychiatry Research 210 (2013) 612–617
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Disordered eating behaviors in adolescents and adults living in the same household in metropolitan area of Rio de Janeiro, Brazil Julia Elba de Souza Ferreira a, Paulo Roberto Borges de Souza Jr.b, Rosana Salles da Costa c, Rosely Sichieri d, Gloria Valeria da Veiga c,n a
Department of Health Sciences, Federal University of Triângulo Mineiro, Uberaba, MG, Brazil Department of Information and Communication Science and Technology, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil c Department of Nutrition, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil d Department of Social Medicine – Rio de Janeiro State University, Rio de Janeiro, RJ, Brazil b
art ic l e i nf o
a b s t r a c t
Article history: Received 27 August 2012 Received in revised form 7 June 2013 Accepted 15 June 2013
Objective: To examine the prevalence of disordered eating behaviors among adolescents and adults living in the same household. Methods: We conducted a population-based cross-sectional study developed with a probabilistic sample of 511 adolescents and 1254 adults living in the metropolitan area of Rio de Janeiro, Brazil. The frequency of binge eating, purging, and strict dieting or fasting over the previous 6 months was ascertained using a self-report questionnaire. Results: Binge eating (20.0% vs. 8.4%), strict dieting or fasting (18.9% vs. 2.4%), and purging (3.3% vs. 2.2%) were more frequent among adolescents than adults. There was a significant association between frequency of binge eating and strict dieting or fasting in adults and in adolescents living in the same household. Conclusion: The presence of disordered eating behaviors in adults may be a risk factor for the development of eating disorders in adolescents living in the same household. Thus, the development and implementation of eating disorder interventions should consider incorporating a family component. & 2013 Elsevier Ireland Ltd. All rights reserved.
Keywords: Disordered eating Strict dieting Binge eating Teenagers Adults Low socioeconomic status
1. Introduction The thin body shape idealized as the modern standard or beauty in society may be a contributing factor to the increasing prevalence of disordered eating behaviors, such as engaging in strict diets or fasting, binge eating after long periods of food restriction, or purging behaviors like self-induced vomiting and/or laxative or diuretic misuse (Nunes et al., 2003). Depending on the intensity and frequency with which they occur, these behaviors may be diagnosed as Partial Syndrome Eating Disorder or Eating Disorder Not Otherwise Specified as cited by Diagnostic and Statistical Manual of Mental Disorders, 4th edition (American Psychiatric Association, 1994); they also indicate a risk of developing into full-blown eating disorders (Nunes et al., 2006; Eddy et al., 2008). Adolescents are among the highest risk groups for the development of eating disorders, although the problem is also present
n Correspondence to: Instituto de Nutrição Josué de Castro, Universidade Federal do Rio de Janeiro, Avenue Carlos Chagas Filho, no 373Centro de Ciências da Saúde, Bloco J, 21 andar, Ilha do Fundão, Rio de Janeiro, RJ CEP: 21941-590, Brazil. Tel.: +55 21 2562 6432; fax: 55 21 2280 8343. E-mail address: [email protected] (G.V. da Veiga).
0165-1781/$ - see front matter & 2013 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.psychres.2013.06.021
in adults (Cumella and Kally, 2008; Preti et al., 2009). Until the 1990s, evidence for eating disorders was most frequently reported in the higher social classes (Hesse-Biber et al., 2006). However, recent studies show that the problem is present across social classes (Portela de Santana et al., 2012; Smink et al., 2012). In Brazil, where the increasing prevalence of obesity has been observed mainly in less-advantaged social classes (IBGE, 2010), behaviors inadequate to combat obesity have also been observed among youth with a low socioeconomic status such as fasting or very restrictive diets and self-induced vomiting, use of laxatives or diuretics as compensatory mechanisms to binge episodes. (Vilela et al., 2004; Ferreira and Veiga, 2008b; Alves et al., 2008; Vale et al., 2011). These findings suggest an association between obesity and low socioeconomic status. Disordered eating behaviors in adolescence can be motivated by the media (Derenne and Eugene, 2006), peers (Shomaker and Furman, 2009), and parents (Field et al., 2001; Wertheim et al., 2002; Rodgers and Chabrol, 2009), however parental influences were an important source of pressure, independently of media or peer influence, in the prediction of the appearance of weight concerns or constant dieting in adolescents (Field et al., 2001). For instance Wertheim et al. (2002) observed that parents who had previously taken part in weight loss programs encouraged their
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children to engage in weight-reduction diets regardless of their weight status. Other studies suggesting that mother's unhealthy eating attitudes may pose a risk for disordered eating in their adolescents (Benedikt et al., 1998; Hill and Franklin, 1998; Field et al., 2005; May et al., 2006). Ogden and Steward (2000) however, did not find maternal influence on the transmission of values related to body dissatisfaction and the practice of dieting to lose weight in their children. In general, these studies analyzed parents' influence on their children's eating behaviors. However, it is possible that the presence of disordered eating behaviors in any adult who lives with the adolescent, even older siblings, cousins, or uncles and aunts, can be a risk factor for the development of such behaviors in adolescents. In Brazil, few studies have assessed the prevalence of disordered eating behaviors, particularly in persons of a low socioeconomic status; the association of such behaviors among adolescents and their parents or legal guardians has not yet been investigated. The purpose of this study was to (a) examine the prevalence of disordered eating behaviors in adolescents and adults living in a low socioeconomic neighborhood of metropolitan area of Rio de Janeiro, Brazil, and (b) determine whether the presence of adults with disordered eating behaviors is associated with the presence of disordered eating behaviors in adolescents living in the same household.
2. Methods 2.1. Sampling and subjects The study was developed to assess adolescents from 12 to 18 years of age and adults 19–85 years of age in a population-based cross-sectional study carried out through household visits in Campos Eliseos, a neighborhood located in a municipality (Duque de Caxias) of metropolitan area of Rio de Janeiro, Brazil. In this neighborhood, 14.5% of the residents live below the extreme poverty line; this proportion represents almost twice the average in the state of Rio de Janeiro (8.7%) (Salles-Costa et al., 2008). A random cluster sampling design was used in three stages of selection. First, 75 census sectors were selected from a total 322 sectors within the study area. Second, the households were selected based on a previously set limit of 15 households per sector, totaling 1125 households. The final sample size was 1085 households (corresponding to 96.4% of the total planned). In the third stage, one adolescent and one adult were selected at random from each of the households in which there was more than one individual in the required age range, except when the household contained only adults. In this situation, two adults were randomly selected for assessment. One thousand two hundred eighty-two adults and 561 adolescents were assessed. Considering an estimated prevalence of disordered eating behaviors of approximately 20% (Sampei et al., 2009), confidence level of 95%, absolute precision of 5%, and a cluster sampling design, this sample size allows for estimating the prevalence of such behaviors in the adolescent population evaluated. For adults, the investigated sample allows for estimating the prevalence of such behaviors with absolute precision of 2% (Lwanga and Lemeshow, 1991). To investigate the association of disordered eating behaviors among adolescents and adults, complete data from 508 pairs of adults and adolescents living in the same household were obtained, considering only one randomly selected adult in cases where more than one adult lived with the adolescent. The adult respondent could be any adult living in the household; he or she was not required to be one of the adolescent's parents.
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Table 1 Distribution of adolescents and adults by sex, age group and body mass index (BMI) classification. Duque de Caxias, RJ, Brazil, 2005. Variables
Adolescents
Adults
n
%
n
%
Sex Male Female
(N¼ 511) 252 259
49.3 50.7
(N¼ 1254) 496 758
32.8 67.2
Age group (years) 12–14 15–18 19–29 30–39 40–49 ≥50 years old
229 282 – – – –
44.9 55.1 – – – –
– (N¼ 1247) 338 355 202 352
27.1 28.4 16.2 28.3
BMI classification Underweight Normal weight Overweight Obesity
(N¼ 506) 18 367 85 36
3.5 72.5 16.8 7.2
(N¼ 920) 32 440 316 132
3.5 47.8 34.3 14.4
–
There was loss of information of five adolescents and 334 adults for BMI classification and of seven adults for age group variable. In order to determine whether respondents engaged in strict dieting or fasting and purging behaviors at least once per week, respondents were asked the following question: “Over the last six months, did you regularly use (at least once a week), any method to control your weight such as… laxatives, diuretics or selfinduced vomiting?… very strict diets or fasting?” Adolescents' and adults' weights were measured by means of electronic scales (Kratos PPSs, São Paulo, Brazil) with a capacity of 150 kg and variation of 100 g. Height was measured using a portable stadiometer (Leicesters, United Kingdom) with a variation of 0.1 cm. The subjects wore light clothing and were barefoot at the time of this assessment. Adolescents were classified as low weight, normal weight, overweight, or obese on the basis of age- and sex-specific body mass index (BMI ¼weight (kg)/[height (m)]²) cut-offs according to the criteria set by the World Health Organization (WHO; de Onis et al., 2007). For adults, similar BMI cut-offs were set following WHO criteria (WHO, 1998). 2.3. Data analysis The complex cluster-sample design involved two stages and required taking into account both sample weights and clustering (Beckett et al., 1992; Sousa and Silva, 2003). Statistical analyses were performed using the procedures for complex samples included in the Statistical Package for the Social Sciences (SPSS version 19.0., Chicago, IL, USA). The prevalence of disordered eating behaviors was compared between sex, age groups (12–14 years and 15–18 years for adolescents; 19–29 years, 30–49 years, and ≥50 years for adults), and BMI classification groups, using the chi-square test and 0.05 as the threshold for statistical significance. The prevalence ratio (PR) and 95% confidence intervals (95% CI) were calculated in order to measure the strength of the association between the prevalence of disordered eating behaviors among adolescents and among adults. To investigate this association we considered the presence of disordered eating behaviors among adults as a possible risk factor for the presence of disordered eating behaviors among adolescents. We adopted this approach because in general, adolescents are more likely to be influenced by adult behavior (Rodgers and Chabrol, 2009) than the reverse. The broader study from which the data used in the present study originated was approved by the Research Ethics Committee of Rio de Janeiro State University, Brazil.
2.2. Data collection
3. Results
The data were collected between May and December of 2005 by a well-trained team of 16 interviewers and 6 nutritionists. Eating behaviors were evaluated using a self-report questionnaire, which had been utilized in previous studies for tracking eating disorders, both binge eating (Siqueira et al., 2005; Ferreira and Veiga, 2008b; Freitas et al., 2008) and strict dieting or fasting and purging (Ferreira and Veiga, 2008b). Binge eating was assessed on the basis of the definition proposed in the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (American Psychiatric Association, 1994), using the following: “Have you ever eaten an amount of food greater than that most people would eat in a period of two hours or less? If so, did you feel unable to stop eating or to control how much you were eating?”
Data from 511 adolescents (91% response rate) and 1254 adults (97.8% response rate) were examined. Their characteristics are presented in Table 1. Half of the adolescents were female and slightly more than half were between 15 and 18 years old. Between adults the proportion of women was twice the proportion of men (67.2% vs. 32.8%) and the highest of the adults were between 19 and 39 years old. Overweight was more prevalent than underweight in both adults (48.7% vs. 3.5%) and adolescents (24.0% vs. 3.5%).
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Both binge eating and strict dieting or fasting were more frequent among adolescents than adults, regardless of sex. Strict dieting or fasting was more frequent among girls than boys (23.7% vs. 13.7, p ¼0.02). Among adults, all disordered eating behaviors were more frequent among women than men (Table 2). There was no difference in the prevalence of disordered eating behaviors between age groups among adolescents but the prevalence of binge eating was shown to decrease as age increased among adults (12.7% at 19–29 years, 8.1% at 30–39, and 4.5% ≥50 years). Binge eating and strict dieting or fasting were more frequently found among overweight adolescents and binge eating and purging behaviors were more frequently found among underweight adolescents than normal weight adolescents. In adults, no significant association was found between disordered eating behaviors and BMI classification (Table 3). The prevalence of binge eating and strict dieting or fasting was more than twice as high among adolescents who lived with adults reporting such behaviors than among adolescents who lived with adults not endorsing disordered eating behaviors. The effect of the practice of strict dieting in adults on the same practice in adolescents was observed when the adults were 19–29 years old (PR: 4.13; 95% CI ¼1.13–15.11) and 30–49 years old (PR: 2.65; 95% CI 1.37–5.12), (Table 4).
4. Discussion The main finding of the present study was the high prevalence of disordered eating behaviors in the adolescents and adults under
investigation, especially among female adolescents. As hypothesized, the household presence of adults with disordered eating behaviors appeared to increase the risk of such behaviors in adolescents. Our findings highlight the need for a family component in intervention measures designed to control disordered eating behaviors in adolescents. The prevalence of binge eating in adolescents was shown to be high (21.8% in male and 18.1% in females), although lower than that described in students from public schools in Niterói city also located in metropolitan area of Rio de Janeiro, Brazil (25% for boys and 40% for girls; Ferreira and Veiga, 2008b). The prevalence of strict dieting or fasting found in our study was slightly higher for boys (13.7%) and slightly lower for girls (23.7%), when compared to the results observed in the Niterói students (10.6% and 31.2%, respectively; Ferreira and Veiga, 2008b). For adults, the proportion of 3.7% reporting strict dieting or fasting was very similar to the prevalence observed by Hay et al. (2008) in the Australian population (4.6%). The higher frequency of the practice of strict dieting in girls than in boys is congruent with results from other studies (O'Connor et al., 2003; Kjelsås et al., 2004; Ferreira and Veiga, 2008b; Grave, 2011). This could perhaps be explained by the fact that women may be more susceptible to the current concept of beauty, which focuses on thinness (Vale et al., 2011). The practice of strict dieting or fasting has also been more frequent among overweight adolescents than among normal weight adolescents; this is compatible with findings from other studies (FernandezAranda et al., 2007; Sancho et al., 2007; Ferreira and Veiga, 2008b; Babio et al., 2009). In fact, strict diets do not necessarily result in
Table 2 Weighted prevalence of disordered eating behaviors in adolescents and adults by sex. Duque de Caxias, RJ, Brazil, 2005. Disordered Eating Behaviors
Adolescents
Adults
Male, N ¼249 (%)
Binge Eating Purging Behaviors Strict dieting or fasting n
21.8 2.0 13.7
Female, N¼ 259 (%)
p-Value*
18.1 4.6 23.7
0.43 0.10 0.02
p-Value*
Male, N ¼ 489 (%)
5.3 0.5 0.5
Female, N ¼ 757 (%)
10.4 3.3 3.7
p-Value*
0.004 0.03 o 0.001
Adolescents adults Male
Female
o 0.001 0.19 o 0.001
0.009 0.61 o0.001
Obtained by Chi-square test.
Table 3 Weighted prevalence of disordered eating behaviors in adolescents and adults by age group (years) and body mass index (BMI) classification. Duque de Caxias, RJ, Brazil, 2005. Disordered Eating Behaviors
Adolescents
Adults
12–14, N ¼ 228 (%)
15–18, N ¼ 279*(%)
p-Value
Binge Eating Purging Behaviors Strict Dieting
21.0 2.9 17.5
19.1 3.6 20.0
0.65 0.67 0.52
Disordered Eating Behaviors
Adolescents
Binge Eating Purging Behaviors Strict Dieting □
□
19–29, N ¼337♦ (%)
30–49, N ¼552☼ (%)
≥50, N ¼350ξ (%)
p-Value□
12.7a 2.8 1.8
8.1a 2.1 2.9
4.4b 1.8 2.2
0.03 0.80 0.59
Adults □
Underweight, N ¼ 23 (%)
Normal weight, N ¼ 363 (%)
Overweight, N¼ 121 (%)
p-Value
Underweight, N ¼31 (%)
normal weight, N ¼440 (%)
Overweight, N ¼ 444 (%)
p-Value□
33.1ª,b 11.6a 8.9a
16.1b 1.9 b 15.6a
29.1a 5.8c 30.4b
0.02 0.01 0.01
12.5 0 0
6.8 1.2 1.3
9.3 4.2 1.9
0.49 0.18 0.70
Obtained by Chi-square test: values with different letters¼p o 0.05 to show differences in disordered eating behaviors among groups. There was loss of information of two adolescents for purging and of three adolescents for strict dieting. ♦ There was loss of information of one adolescent for purging and strict dieting. ☼ There was loss of information of one adolescent for purging and five adolescents for strict dieting. ξ There was loss information of six adolescents for purging and 4 adolescents for strict dieting. n
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Table 4 Prevalence ratio, confidence interval of 95% and proportional attributable risk for association between disordered eating behaviors among adolescents and adults living in the same household by adults' sex and age group. Duque de Caxias-RJ, Brazil, 2005. Disordered eating behavior in adolescents % Disordered eating behavior in adults Binge eating Yes 38.7 No 17.2 Strict dieting or fasting Yes 43.2 No 17.9
PR (CI 95%)
2.25 (1.39–3.63) 1.00 2.41 (1.3–4.36) 1.00
Disordered eating behavior in adult womena Binge eating Yes 32.3 No 15.6 Strict dieting or fasting Yes 50.3 No 16.1
3.12 (1.70–5.75) 1.00
Disordered eating behavior in adult menb Binge eating Yes 53.1 No 18.9
2.81 (1.30–6.08) 1.00
2.07 (1.23–3.49) 1.00
Disordered eating behavior in adults from 19 to 29.9 years olda Binge eating Yes 34.3 1.81 (0.61–5.29) No 18.9 1.00 Strict dieting or fasting Yes 49.9 4.13 (1.13–15.11) No 12.0 1.00 Disordered eating behavior in adults from 30 to 49.9 years olda Binge eating Yes 42.9 2.52 (1.44–4.42) No 17.0 1.00 Strict dieting or fasting Yes 50.0 2.65 (1.37–5.12) No 18.8 1.00 Disordered eating behavior in adults ≥50 years olda Binge eating Yes 6.3 0.44 (0.04–4.39) No 14.1 1.00 Strict dieting or fasting Yes 14.1 0.68 (0.05–8.72) No 20.5 1.00 PR—prevalence ratio; CI 95%—confidence interval of 95%. a Purging behaviors was excluded, because there was not this behavior among adults. b Purging behaviors and strict dieting or fasting were excluded, because there weren´t these behaviors among adults.
thinness (Field et al., 2003); rather, they can be a precipitant factor for the binge eating that arises following repeated excessive food restriction, characterizing the binge eating behaviors. In the present study, the prevalence (3.3%) of purging behaviors in adolescents was lower than that of other disordered eating behaviors we investigated. However, it was no less important, because such behaviors are unacceptable and quite harmful to adolescent health, particularly among underweight adolescents in whom this behavior was more frequent (11.6%). Interestingly, for adults, the prevalence (2.2%) of purging behaviors was greater than the 1% prevalence observed in two similar studies of the South Australian population (Hay et al., 2008; Mitchison et al., 2012). The prevalence of binge eating in females (10.4%) and males (5.3%) in this study was lower than that observed by Siqueira et al. (2005) in adults at frequent shopping centers in five Brazilian
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capitals (13% among women and 12.8% among men). Freitas et al. (2008) also found a much higher prevalence of binge eating (20.6%) in women residents in the city of Rio de Janeiro. However, the prevalence observed for purging behaviors was similar in both studies (about 3%). Both Freitas et al. and Siqueira et al. investigated a population with a higher socioeconomic status than that investigated in the current study which could explain such differences. However, the relationship between socioeconomic status and disordered eating behaviors is not well understood. An inverse association was observed in Ecuadorian adolescents (Power et al., 2008), and in Portuguese adolescents, associations were found to be dependent on sex, being directly associated for girls and inversely associated for boys (Costa et al., 2008). Further, no association was observed in Brazilian adolescents (Dunker et al., 2009). The lower prevalence observed in our study could also be explained by under-reporting, since purging and binging are considered shameful behaviors. However, in our study as well as in the Siqueira et al. (2005) study, the self-report questionnaire was utilized intentionally to minimize any embarrassment or shame that might arise during a face-to-face interview. Despite the high prevalence of disordered eating behaviors among adults, particularly among women, our study demonstrates that the problem occurs on a larger scale among adolescents, regardless of sex. Such results indicate that during adolescence, even males are at risk. Currently, men desire a much leaner and more muscular body than the body they actually have or perceive themselves to have (Pope et al., 2000; Rodgers et al., 2012). The pursuit of muscularity can lead to use of unhealthy, muscleenhancing behaviors whose prevalence is particularly high in boys (Eisenberg et al., 2012). These unhealthy behaviors could then lead to disordered eating behaviors that have been observed in different ethnic groups (Ricciardelli et al., 2007). Although the prevalence of disordered eating behaviors among adults was meaningful, findings from this study also suggest that adults living in the same household as an adolescent could influence that adolescent to develop the same behavior. In fact, the presence of binge eating and strict dieting or fasting in adults doubled the risk that adolescents living in the same household would exhibit the same behavior in accordance with the findings of Yanez et al. (2007), who found that girls whose mothers demonstrated unhealthy attitudes about eating had three times higher the risk of developing the same behavior than those whose mothers did not demonstrate such attitudes. In our study, we also found that among adolescents who lived with women reporting binge eating and the practice of strict dieting, the prevalence of these behaviors was approximately three times greater than that among the adolescents who lived with women who did not report these behaviors. These results concur with the findings of Sampei et al. (2009), who observed that 33.5% of Caucasian adolescents and 22.1% of Japanese– Brazilian adolescents were motivated by their mothers to engage in strict dieting. In a Spanish study Canals et al. (2009) also found significant associations between mothers' weight loss behaviors and disordered eating behaviors in their daughters. According to our results, male adults also seem to influence adolescents' eating practices: the presence of an adult man engaging in binge eating at home almost tripled the prevalence of this behavior in adolescents in the same household. The findings of our study in combination with the relevant literature (Adami-Lauand and Ribeiro, 2011) support the proposition that the psychodynamics of family interaction is an important factor in determining the development and maintenance of eating disorders. Indeed adult family members who have excessive concern with dieting and weight may negatively affect the development and maintenance of eating disorders in their offspring. Among family factors, emphasis is frequently placed on psychoanalytic viewpoints
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and genetic predisposition. From a psychoanalytic perspective, abnormal mother–daughter relationships are considered to underlie the later development of eating disorders (Betancourt et al., 2007). Further, one longitudinal genetic study (Strober et al., 2000) showed that, in female relatives of anorexic and bulimic probands, the relative risks were 11.3 and 12.3 for the full syndrome of anorexia nervosa and 4.2 and 4.4 for the full syndrome of bulimia nervosa, respectively. The authors then argued that anorexia nervosa and bulimia nervosa are indicative of at least some sharing of familial genetics. Currently, studies estimate that the heritability of eating disorders varies from 40% to 60% (Trace et al., 2013). The findings of all of these studies have contributed to the interpretation of the current work. It is important to address the limitations of this study. Adult participants were randomly chosen and the respondent in the same household was not required to be the adolescent's parent, thus generalization of findings to association with adolescent's parent is limited. However, among the 1085 households evaluated, 32.1% had a woman without a partner (single or divorced) as the head of the household, 37% included children aged from 6 to 30 months, and fewer than 0.5% had more distant relatives living together (data not shown). This allows us to conclude that the adult respondent was most often directly related to the adolescent. Moreover, the method applied in this study allowed us to identify the possible influence of older siblings, since the association between the practice of strict dieting or fasting among young adults aged 19–29 years (unlikely to be parents of teenagers) and the same behavior in adolescents was also significant. Additionally the cross-sectional study design does not permit establishment of causality of the associations between the disordered eating behavior in adults and adolescents. It is possible that the adults could be influenced by the adolescents. Nevertheless, we believe that the reverse is more likely, since in general, adolescents follow their elders' example (Rodgers and Chabrol, 2009). It is important to stress that diagnosis of eating disorders is only possible through clinical interviewing. Thus, this study does not claim to diagnose eating disorders, but rather to determine the risk factors for the development of these disorders in adolescent and adult residents of an area where the majority of residents are of lower socioeconomic status, because such behaviors have been scarcely investigated in this population. So, this study was also hindered by the fact that the questions used to assess disordered eating behaviors were simplistic and did not encompass the full spectrum of eating disorder symptomatology. However, although the questionnaire was comparatively short and simple, the questions addressed important topics relevant to the primary risk factors for eating disorders. The reproducibility of these questions was considered moderate to excellent in a previous study using data from Brazilian adolescents (Ferreira and Veiga, 2008a). Moreover, this simplified approach is appropriate for tracking the issue in epidemiological studies, particularly in people from lower-income social backgrounds with low levels of education, similar to the population investigated in this study, where long and complex questionnaires could be difficult to understand and accurately complete. We conclude that the prevalence of disordered eating behaviors among adolescents is high and that the presence at home of adults with disordered eating behaviors may influence adolescents to acquire similar behaviors. Therefore, adults should be educated about the important role they may play in shaping eating behaviors in adolescents. They should also be informed about interventions aimed at the prevention and control of disordered eating behaviors in adolescents. In both clinical practice and as part of public health initiatives, such interventions should be directed toward both adolescents and the adults with whom they live aiming to be increasingly effective.
References Adami-Lauand, C.B., Ribeiro, R.P.P., 2011. A herança transgeracional nos transtornos alimentares: algumas reflexões. (Transgenerational inheritance in eating disorders: some reflections). Psicologia USP 22, 927–942. Alves, E., Vasconcelos, F.A.G., Calvo, M.C.M., Neves, J., 2008. Prevalência de sintomas de anorexia nervosa e insatisfação com a imagem corporal em adolescentes do sexo feminino do Município de Florianópolis, Santa Catarina, Brasil (Prevalence of symptoms of anorexia nervosa and dissatisfaction with body image among female adolescents in Florianópolis, Santa Catarina State, Brazil). Cadernos de Saúde Pública 24, 503–512. American Psychiatric Association, 1994. Diagnostic and Statistical Manual of Mental Disorders DSM-IV. Washington, DC. Babio, N., Canals, J., Pietrobelli, A., Pérez, S., Arija, A., 2009. A two-phase population study: relationships between overweight, body composition and risk of eating disorders. Nutrición Hospitalaria 24, 485–491. Beckett, L.A., Scherr, P.A., Evans, D.A., 1992. Population prevalence estimates from complex samples. Journal of Clinical and Epidemiology 45, 393–402. Benedikt, R., Wertheim, E.H., Love, A., 1998. Eating attitudes and weight loss attempts in female adolescents and their mothers. Journal of Youth and Adolescence 27, 43–57. Betancourt, L., Rodríguez Guarín, M., Gempeler Rueda, J., 2007. Interacción madrehijo, patrones de apego y su papel en los trastornos del comportamiento alimentario. Universitas Médica 48, 261–276. Canals, J., Sancho, C., Arija, M.V., 2009. Influence of parent's eating attitudes on eating disorders in school adolescents. European Child & Adolescent Psychiatry 18, 353–359. Costa, C., Ramos, E., Severo, M., Barros, H., Lopes, C., 2008. Determinants of eating disorders symptomatology in Portuguese adolescents. Archives of Pediatrics & Adolescent Medicine 162, 1126–1132. Cumella, E.J., Kally, Z., 2008. Comparison of middle-age and young women in patients with eating disorders. Eating and Weight Disorders 13, 183–190. de Onis, M., Onyango, A.W., Borghi, E., Siyam, A., Nishida, C., Siekmann, J., 2007. Development of a WHO growth reference for school-aged children and adolescents. Bulletin of the World Health Organization 85, 660–667. Derenne, J.L., Eugene, V.B., 2006. Body image, media, and eating disorders. Academic Psychiatry 30, 257–261. Dunker, K.L.L., Fernandes, C.P.B., Carreira Filho, D., 2009. Influência do nível socioeconômico sobre comportamentos de risco para transtornos alimentares em adolescentes. (Socioeconomic influence on eating disorders risk behaviors in adolescents). Jornal Brasileiro de Psiquiatria 58, 156–161. Eddy, K.T., Celio Doyle, A., Hoste, R.R., Herzog, D.B., le Grange, D., 2008. Eating disorder not otherwise specified in adolescents. Journal of the American Academy of Child and Adolescent Psychiatry 47, 156–164. Eisenberg, M.E., Wall, M., Neumark-Sztainer, D., 2012. Muscle-enhancing behaviors among adolescent girls and boys. Pediatric 130, 1019–1026. Fernandez-Aranda, F., Krug, I., Granero, R., Ramón, J.M., Badia, A., Gimenez, L., Solano, R., Collier, D., Karwautz, A., Treasure, J., 2007. Individual and family eating patterns during childhood and early adolescence: an analysis of associated eating disorder factors. Appetite 49, 476–485. Ferreira, J.E.S., Veiga, G.V., 2008a. Confiabilidade (teste-reteste) de um questionário simplificado para avaliar comportamentos de risco para transtornos alimentares em adolescentes. (Test-retest reliability of a simplified questionnaire for screening adolescents with risk behaviors for eating disorders in epidemiologic studies). Revista Brasileira de Epidemiologia 11, 393–401. Ferreira, J.E.S., Veiga, G.V., 2008b. Eating disorder risk behavior in Brazilian adolescents from low socioeconomic level. Appetite 51, 249–255. Field, A.E., Camargo, C.A., Taylor, C.B., Berkey, C.S., Roberts, S.B., Colditz, G.A., 2001. Peer, parent, and media influences on the development of weight concerns and frequent dieting among preadolescent and adolescent girls and boys. Pediatrics 107, 54–60. Field, A.E., Austin, S.B., Taylor, C.B., Malspeis, S., Rosner, B., Rockett, H.R., 2003. Relation between dieting and weight change among preadolescents and adolescents. Pediatrics 112 (Suppl. IV), 900–906. Field, A.E., Austin, S.B., Striegel-Moore, R., Taylor, C.B., Camargo, C.A., Laird, N., Colditz, G., 2005. Weight concerns and weight control behaviors of adolescents and their mothers. Archives of Pediatrics & Adolescent Medicine 159, 1121–1126. Freitas, S.R., Appolinário, J.C., Souza, A.M., Schieri, R., 2008. Prevalence of binge eating and associated factors in a Brazilian probability sample of midlife women. International Journal of Eating Disorders 41, 471–478. Grave, R.D., 2011. Eating disorders: progress and challenges. European Journal of Internal Medicine 22, 153–160. Hay, P.J., Mond, J., Buttner, P., Darby, A., 2008. Eating disorder behaviors are increasing: findings from two sequential community surveys in South Australia. PLoS ONE 3, 1–5. Hesse-Biber, S., Leavy, P., Quinn, C.E., Zoino, J., 2006. The mass marketing of disordered eating and eating disorders: the social psychology of women, thinness and culture. Womens's Studies International Forum 29, 208–224. Hill, A.J., Franklin, J.A., 1998. Mothers, daughters and dieting: investigating the transmission of weight control. British Journal of Clinical Psychology 37, 3–13. Instituto Brasileiro de Geografia e Estatística, 2010. Pesquisa de Orçamentos Familiares 2008–2009. Antropometria e estado nutricional de crianças, adolescentes e adultos no Brasil (Household Budget Survey 2008–2009). (Anthropometry and nutritional status of children, adolescents and adults in Brazil). Instituto Brasileiro de Geografia e Estatística, Rio de Janeiro. Retrieved from 〈http://www.ibge.gov.br〉.
J.E.d.S. Ferreira et al. / Psychiatry Research 210 (2013) 612–617
Kjelsås, E., Bjørnstrøm, C., Götestam, K.G., 2004. Prevalence of eating disorders in female and male adolescents (14–15 years). Eating Behaviors 5, 13–25. Lwanga, S.K., Lemeshow, S., 1991. Sample Size Determination in Health Studies: A Practical Manual. World Health Organization, Geneva. May, A.L., Kim, J.Y., McHale, S.M., Crouter, A., 2006. Parent–adolescent relationships and the development of weight concerns from early to late adolescence. International Journal of Eating Disorders 39, 729–740. Mitchison, D., Hay, P., Slewa-Younan, S., Mond, J., 2012. Time trends in population prevalence of eating disorder behaviors and their relationship to quality of life. PLoS ONE 7, 1–7. Nunes, M.A., Barros, F.C., Anselmo, O.M.T., Camey, S., Mari, J.D., 2003. Prevalence of abnormal eating behaviors and inappropriate methods of weight control in young women from Brazil: a population-based study. Eating and Weight Disorders 8, 100–106. Nunes, M.A., Olinto, M.T., Camey, S., Morgan, C., Mari, J.J., 2006. Abnormal eating behaviors in adolescent and young adult women from southern Brazil: reassessment after four years. Social Psychiatry Epidemiology 41, 951–956. O’Connor, M., Simmons, T., Cooper, M., 2003. Assumptions and beliefs, dieting, and predictors of eating disorder-related symptoms in young women and young men. Eating Behaviors 4, 1–6. Ogden, J., Steward, J., 2000. The role of the mother–daughter relationship in explaining weight concern. International Journal of Eating Disorders 28, 78–83. Pope Jr., H.G., Gruber, A.J., Mangweth, B., Bureau, B., deCol, C., Jouvent, R., Hudson, J.I., 2000. Body image perception among men in three countries. American Journal of Psychiatry 157, 1297–1301. Portela de Santana, M.L., da Costa Ribeiro Junior, H., Mora Giral, M., Raich, R.M., 2012. Epidemiology and risk factors of eating disorder in adolescence: a review. Nutrición Hospitalaria 27, 391–401. Power, Y., Power, L., Canadas, M.B., 2008. Low socioeconomic status predicts abnormal eating attitudes in Latin American female adolescents. Eating Disorders 16, 136–145. Preti, A., Girolamo, G., Vilagut, G., Alonso, J., Graaf, R., Bruffaerts, R., Demyttenaere, K., Pinto-Meza, A., Haro, J.M., Morosini, P., ESEMeD-WMH Investigators, 2009. The epidemiology of eating disorders in six European countries: results of the ESEMeD-WMH project. Journal of Psychiatric Research 43, 1125–1132. Ricciardelli, L.A., McCabe, M.P., Williams, R.J., Thompson, K.J., 2007. The role of ethnicity and culture in body image and disordered eating among males. Clinical Psychology Review 27, 582–606. Rodgers, R., Chabrol, H., 2009. Parental attitudes, body image disturbance and disordered eating amongst adolescents and young adults: a review. European Eating Disorders Review 17, 137–151. Rodgers, R.F., Ganchou, C., Franko, D.L., Chabrol, H., 2012. Drive for muscularity and disordered eating among French adolescent boys: a sociocultural model. Body Image 9, 318–323.
617
Salles-Costa, R., Pereira, R.A., Vasconcellos, M.T.L., Veiga, G.V., Marins, V.M.R., Jardim, B.C., Gomes, F.S., Sichieri, R., 2008. Associação entre fatores socioeconômicos e insegurança alimentar: estudo de base populacional na Região Metropolitana do Rio de Janeiro, Brasil (Association between socioeconomic factors and food insecurity: a population-based study in the Rio de Janeiro metropolitan area, Brazil). Revista de Nutrição 21 (Supl.), 99s–109s. Sampei, M.A., Sigulem, D.M., Novo, N.F., Juliano, Y., Colugnati, F.A.B., 2009. Eating attitudes and body image in ethnic Japanese and Caucasian adolescent girls in the city of São Paulo, Brazil. Jornal de Pediatria 85, 122–128. Sancho, C., Arija, A., Asorey, O., Canals, J., 2007. Epidemiology of eating disorders: a two year follow up study in an early adolescent school population. European Child & Adolescent Psychiatry 16, 495–504. Shomaker, L.B., Furman, W., 2009. Interpersonal influences on late adolescent girls' and boys' disordered eating. Eating Behaviors 10, 97–106. Siqueira, K.S., Appolinário, J.C., Schieri, R., 2005. Relationship between binge-eating episodes and self-perception of body weight in a nonclinical sample of five Brazilian cities. Revista Brasileira de Psiquiatria 27, 290–294. Smink, F.R.E., Hoeken, D.V., Hoek, H.W., 2012. Epidemiology of eating disorders: incidence, prevalence and mortality rates. Current Psychiatry Reports 14, 406–414. Sousa, M.H., Silva, N.N., 2003. Estimativas obtidas de um levantamento complexo (Estimates from a complex survey). Revista de Saúde Pública 37, 662–670. Strober, M., Freeman, R., Lampert, C., Diamond, J., Kaye, W., 2000. Controlled family study of anorexia nervosa and bulimia nervosa: evidence of shared liability and transmission of partial syndromes. American Journal of Psychiatry 157 (3), 393–401. Trace, S.E., Baker, J.H., Peñas-Lledó, E., Bulik, C.M., 2013. The genetics of eating disorders. Annual Review of Clinical Psychology 9, 589–620. Vale, A.M.O., Kerr, L.R.S., Bosi, M.L.M., 2011. Risk behaviors for eating disorders among female adolescents from different social strata in the Brazilian Northeastern. Ciência & Saúde Coletiva 16, 121–132. Vilela, J.E.M., Lamounier, J.A., Dellaretti, M.A., Barros Neto, J.R., Horta, G.M., 2004. Anorexia nervosa, bulimia nervosa, inappropriate eating behaviors, epidemiology. Pediatrics 80, 49–54. Wertheim, E.H., Martin, G., Prior, M., Sanson, A., Smart, D., 2002. Parent influences in the transmission of eating and weight related values and behaviors. Eating Disorders 10, 321–334. World Health Organization, 1998. Yanez, A.M., Peix, M.A., Atserias, N., Arnau, A., Brug, J., 2007. Association of eating attitudes between teenage girls and their parents. International Journal of Social Psychiatry 53, 507–513.
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Disordered eating behaviors in adolescents and adults living in the same household in metropolitan area of Rio de Janeiro, Brazil Julia Elba de Souza Ferreira a, Paulo Roberto Borges de Souza Jr.b, Rosana Salles da Costa c, Rosely Sichieri d, Gloria Valeria da Veiga c,n a
Department of Health Sciences, Federal University of Triângulo Mineiro, Uberaba, MG, Brazil Department of Information and Communication Science and Technology, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil c Department of Nutrition, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil d Department of Social Medicine – Rio de Janeiro State University, Rio de Janeiro, RJ, Brazil b
art ic l e i nf o
a b s t r a c t
Article history: Received 27 August 2012 Received in revised form 7 June 2013 Accepted 15 June 2013
Objective: To examine the prevalence of disordered eating behaviors among adolescents and adults living in the same household. Methods: We conducted a population-based cross-sectional study developed with a probabilistic sample of 511 adolescents and 1254 adults living in the metropolitan area of Rio de Janeiro, Brazil. The frequency of binge eating, purging, and strict dieting or fasting over the previous 6 months was ascertained using a self-report questionnaire. Results: Binge eating (20.0% vs. 8.4%), strict dieting or fasting (18.9% vs. 2.4%), and purging (3.3% vs. 2.2%) were more frequent among adolescents than adults. There was a significant association between frequency of binge eating and strict dieting or fasting in adults and in adolescents living in the same household. Conclusion: The presence of disordered eating behaviors in adults may be a risk factor for the development of eating disorders in adolescents living in the same household. Thus, the development and implementation of eating disorder interventions should consider incorporating a family component. & 2013 Elsevier Ireland Ltd. All rights reserved.
Keywords: Disordered eating Strict dieting Binge eating Teenagers Adults Low socioeconomic status
1. Introduction The thin body shape idealized as the modern standard or beauty in society may be a contributing factor to the increasing prevalence of disordered eating behaviors, such as engaging in strict diets or fasting, binge eating after long periods of food restriction, or purging behaviors like self-induced vomiting and/or laxative or diuretic misuse (Nunes et al., 2003). Depending on the intensity and frequency with which they occur, these behaviors may be diagnosed as Partial Syndrome Eating Disorder or Eating Disorder Not Otherwise Specified as cited by Diagnostic and Statistical Manual of Mental Disorders, 4th edition (American Psychiatric Association, 1994); they also indicate a risk of developing into full-blown eating disorders (Nunes et al., 2006; Eddy et al., 2008). Adolescents are among the highest risk groups for the development of eating disorders, although the problem is also present
n Correspondence to: Instituto de Nutrição Josué de Castro, Universidade Federal do Rio de Janeiro, Avenue Carlos Chagas Filho, no 373Centro de Ciências da Saúde, Bloco J, 21 andar, Ilha do Fundão, Rio de Janeiro, RJ CEP: 21941-590, Brazil. Tel.: +55 21 2562 6432; fax: 55 21 2280 8343. E-mail address: [email protected] (G.V. da Veiga).
0165-1781/$ - see front matter & 2013 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.psychres.2013.06.021
in adults (Cumella and Kally, 2008; Preti et al., 2009). Until the 1990s, evidence for eating disorders was most frequently reported in the higher social classes (Hesse-Biber et al., 2006). However, recent studies show that the problem is present across social classes (Portela de Santana et al., 2012; Smink et al., 2012). In Brazil, where the increasing prevalence of obesity has been observed mainly in less-advantaged social classes (IBGE, 2010), behaviors inadequate to combat obesity have also been observed among youth with a low socioeconomic status such as fasting or very restrictive diets and self-induced vomiting, use of laxatives or diuretics as compensatory mechanisms to binge episodes. (Vilela et al., 2004; Ferreira and Veiga, 2008b; Alves et al., 2008; Vale et al., 2011). These findings suggest an association between obesity and low socioeconomic status. Disordered eating behaviors in adolescence can be motivated by the media (Derenne and Eugene, 2006), peers (Shomaker and Furman, 2009), and parents (Field et al., 2001; Wertheim et al., 2002; Rodgers and Chabrol, 2009), however parental influences were an important source of pressure, independently of media or peer influence, in the prediction of the appearance of weight concerns or constant dieting in adolescents (Field et al., 2001). For instance Wertheim et al. (2002) observed that parents who had previously taken part in weight loss programs encouraged their
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children to engage in weight-reduction diets regardless of their weight status. Other studies suggesting that mother's unhealthy eating attitudes may pose a risk for disordered eating in their adolescents (Benedikt et al., 1998; Hill and Franklin, 1998; Field et al., 2005; May et al., 2006). Ogden and Steward (2000) however, did not find maternal influence on the transmission of values related to body dissatisfaction and the practice of dieting to lose weight in their children. In general, these studies analyzed parents' influence on their children's eating behaviors. However, it is possible that the presence of disordered eating behaviors in any adult who lives with the adolescent, even older siblings, cousins, or uncles and aunts, can be a risk factor for the development of such behaviors in adolescents. In Brazil, few studies have assessed the prevalence of disordered eating behaviors, particularly in persons of a low socioeconomic status; the association of such behaviors among adolescents and their parents or legal guardians has not yet been investigated. The purpose of this study was to (a) examine the prevalence of disordered eating behaviors in adolescents and adults living in a low socioeconomic neighborhood of metropolitan area of Rio de Janeiro, Brazil, and (b) determine whether the presence of adults with disordered eating behaviors is associated with the presence of disordered eating behaviors in adolescents living in the same household.
2. Methods 2.1. Sampling and subjects The study was developed to assess adolescents from 12 to 18 years of age and adults 19–85 years of age in a population-based cross-sectional study carried out through household visits in Campos Eliseos, a neighborhood located in a municipality (Duque de Caxias) of metropolitan area of Rio de Janeiro, Brazil. In this neighborhood, 14.5% of the residents live below the extreme poverty line; this proportion represents almost twice the average in the state of Rio de Janeiro (8.7%) (Salles-Costa et al., 2008). A random cluster sampling design was used in three stages of selection. First, 75 census sectors were selected from a total 322 sectors within the study area. Second, the households were selected based on a previously set limit of 15 households per sector, totaling 1125 households. The final sample size was 1085 households (corresponding to 96.4% of the total planned). In the third stage, one adolescent and one adult were selected at random from each of the households in which there was more than one individual in the required age range, except when the household contained only adults. In this situation, two adults were randomly selected for assessment. One thousand two hundred eighty-two adults and 561 adolescents were assessed. Considering an estimated prevalence of disordered eating behaviors of approximately 20% (Sampei et al., 2009), confidence level of 95%, absolute precision of 5%, and a cluster sampling design, this sample size allows for estimating the prevalence of such behaviors in the adolescent population evaluated. For adults, the investigated sample allows for estimating the prevalence of such behaviors with absolute precision of 2% (Lwanga and Lemeshow, 1991). To investigate the association of disordered eating behaviors among adolescents and adults, complete data from 508 pairs of adults and adolescents living in the same household were obtained, considering only one randomly selected adult in cases where more than one adult lived with the adolescent. The adult respondent could be any adult living in the household; he or she was not required to be one of the adolescent's parents.
613
Table 1 Distribution of adolescents and adults by sex, age group and body mass index (BMI) classification. Duque de Caxias, RJ, Brazil, 2005. Variables
Adolescents
Adults
n
%
n
%
Sex Male Female
(N¼ 511) 252 259
49.3 50.7
(N¼ 1254) 496 758
32.8 67.2
Age group (years) 12–14 15–18 19–29 30–39 40–49 ≥50 years old
229 282 – – – –
44.9 55.1 – – – –
– (N¼ 1247) 338 355 202 352
27.1 28.4 16.2 28.3
BMI classification Underweight Normal weight Overweight Obesity
(N¼ 506) 18 367 85 36
3.5 72.5 16.8 7.2
(N¼ 920) 32 440 316 132
3.5 47.8 34.3 14.4
–
There was loss of information of five adolescents and 334 adults for BMI classification and of seven adults for age group variable. In order to determine whether respondents engaged in strict dieting or fasting and purging behaviors at least once per week, respondents were asked the following question: “Over the last six months, did you regularly use (at least once a week), any method to control your weight such as… laxatives, diuretics or selfinduced vomiting?… very strict diets or fasting?” Adolescents' and adults' weights were measured by means of electronic scales (Kratos PPSs, São Paulo, Brazil) with a capacity of 150 kg and variation of 100 g. Height was measured using a portable stadiometer (Leicesters, United Kingdom) with a variation of 0.1 cm. The subjects wore light clothing and were barefoot at the time of this assessment. Adolescents were classified as low weight, normal weight, overweight, or obese on the basis of age- and sex-specific body mass index (BMI ¼weight (kg)/[height (m)]²) cut-offs according to the criteria set by the World Health Organization (WHO; de Onis et al., 2007). For adults, similar BMI cut-offs were set following WHO criteria (WHO, 1998). 2.3. Data analysis The complex cluster-sample design involved two stages and required taking into account both sample weights and clustering (Beckett et al., 1992; Sousa and Silva, 2003). Statistical analyses were performed using the procedures for complex samples included in the Statistical Package for the Social Sciences (SPSS version 19.0., Chicago, IL, USA). The prevalence of disordered eating behaviors was compared between sex, age groups (12–14 years and 15–18 years for adolescents; 19–29 years, 30–49 years, and ≥50 years for adults), and BMI classification groups, using the chi-square test and 0.05 as the threshold for statistical significance. The prevalence ratio (PR) and 95% confidence intervals (95% CI) were calculated in order to measure the strength of the association between the prevalence of disordered eating behaviors among adolescents and among adults. To investigate this association we considered the presence of disordered eating behaviors among adults as a possible risk factor for the presence of disordered eating behaviors among adolescents. We adopted this approach because in general, adolescents are more likely to be influenced by adult behavior (Rodgers and Chabrol, 2009) than the reverse. The broader study from which the data used in the present study originated was approved by the Research Ethics Committee of Rio de Janeiro State University, Brazil.
2.2. Data collection
3. Results
The data were collected between May and December of 2005 by a well-trained team of 16 interviewers and 6 nutritionists. Eating behaviors were evaluated using a self-report questionnaire, which had been utilized in previous studies for tracking eating disorders, both binge eating (Siqueira et al., 2005; Ferreira and Veiga, 2008b; Freitas et al., 2008) and strict dieting or fasting and purging (Ferreira and Veiga, 2008b). Binge eating was assessed on the basis of the definition proposed in the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (American Psychiatric Association, 1994), using the following: “Have you ever eaten an amount of food greater than that most people would eat in a period of two hours or less? If so, did you feel unable to stop eating or to control how much you were eating?”
Data from 511 adolescents (91% response rate) and 1254 adults (97.8% response rate) were examined. Their characteristics are presented in Table 1. Half of the adolescents were female and slightly more than half were between 15 and 18 years old. Between adults the proportion of women was twice the proportion of men (67.2% vs. 32.8%) and the highest of the adults were between 19 and 39 years old. Overweight was more prevalent than underweight in both adults (48.7% vs. 3.5%) and adolescents (24.0% vs. 3.5%).
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Both binge eating and strict dieting or fasting were more frequent among adolescents than adults, regardless of sex. Strict dieting or fasting was more frequent among girls than boys (23.7% vs. 13.7, p ¼0.02). Among adults, all disordered eating behaviors were more frequent among women than men (Table 2). There was no difference in the prevalence of disordered eating behaviors between age groups among adolescents but the prevalence of binge eating was shown to decrease as age increased among adults (12.7% at 19–29 years, 8.1% at 30–39, and 4.5% ≥50 years). Binge eating and strict dieting or fasting were more frequently found among overweight adolescents and binge eating and purging behaviors were more frequently found among underweight adolescents than normal weight adolescents. In adults, no significant association was found between disordered eating behaviors and BMI classification (Table 3). The prevalence of binge eating and strict dieting or fasting was more than twice as high among adolescents who lived with adults reporting such behaviors than among adolescents who lived with adults not endorsing disordered eating behaviors. The effect of the practice of strict dieting in adults on the same practice in adolescents was observed when the adults were 19–29 years old (PR: 4.13; 95% CI ¼1.13–15.11) and 30–49 years old (PR: 2.65; 95% CI 1.37–5.12), (Table 4).
4. Discussion The main finding of the present study was the high prevalence of disordered eating behaviors in the adolescents and adults under
investigation, especially among female adolescents. As hypothesized, the household presence of adults with disordered eating behaviors appeared to increase the risk of such behaviors in adolescents. Our findings highlight the need for a family component in intervention measures designed to control disordered eating behaviors in adolescents. The prevalence of binge eating in adolescents was shown to be high (21.8% in male and 18.1% in females), although lower than that described in students from public schools in Niterói city also located in metropolitan area of Rio de Janeiro, Brazil (25% for boys and 40% for girls; Ferreira and Veiga, 2008b). The prevalence of strict dieting or fasting found in our study was slightly higher for boys (13.7%) and slightly lower for girls (23.7%), when compared to the results observed in the Niterói students (10.6% and 31.2%, respectively; Ferreira and Veiga, 2008b). For adults, the proportion of 3.7% reporting strict dieting or fasting was very similar to the prevalence observed by Hay et al. (2008) in the Australian population (4.6%). The higher frequency of the practice of strict dieting in girls than in boys is congruent with results from other studies (O'Connor et al., 2003; Kjelsås et al., 2004; Ferreira and Veiga, 2008b; Grave, 2011). This could perhaps be explained by the fact that women may be more susceptible to the current concept of beauty, which focuses on thinness (Vale et al., 2011). The practice of strict dieting or fasting has also been more frequent among overweight adolescents than among normal weight adolescents; this is compatible with findings from other studies (FernandezAranda et al., 2007; Sancho et al., 2007; Ferreira and Veiga, 2008b; Babio et al., 2009). In fact, strict diets do not necessarily result in
Table 2 Weighted prevalence of disordered eating behaviors in adolescents and adults by sex. Duque de Caxias, RJ, Brazil, 2005. Disordered Eating Behaviors
Adolescents
Adults
Male, N ¼249 (%)
Binge Eating Purging Behaviors Strict dieting or fasting n
21.8 2.0 13.7
Female, N¼ 259 (%)
p-Value*
18.1 4.6 23.7
0.43 0.10 0.02
p-Value*
Male, N ¼ 489 (%)
5.3 0.5 0.5
Female, N ¼ 757 (%)
10.4 3.3 3.7
p-Value*
0.004 0.03 o 0.001
Adolescents adults Male
Female
o 0.001 0.19 o 0.001
0.009 0.61 o0.001
Obtained by Chi-square test.
Table 3 Weighted prevalence of disordered eating behaviors in adolescents and adults by age group (years) and body mass index (BMI) classification. Duque de Caxias, RJ, Brazil, 2005. Disordered Eating Behaviors
Adolescents
Adults
12–14, N ¼ 228 (%)
15–18, N ¼ 279*(%)
p-Value
Binge Eating Purging Behaviors Strict Dieting
21.0 2.9 17.5
19.1 3.6 20.0
0.65 0.67 0.52
Disordered Eating Behaviors
Adolescents
Binge Eating Purging Behaviors Strict Dieting □
□
19–29, N ¼337♦ (%)
30–49, N ¼552☼ (%)
≥50, N ¼350ξ (%)
p-Value□
12.7a 2.8 1.8
8.1a 2.1 2.9
4.4b 1.8 2.2
0.03 0.80 0.59
Adults □
Underweight, N ¼ 23 (%)
Normal weight, N ¼ 363 (%)
Overweight, N¼ 121 (%)
p-Value
Underweight, N ¼31 (%)
normal weight, N ¼440 (%)
Overweight, N ¼ 444 (%)
p-Value□
33.1ª,b 11.6a 8.9a
16.1b 1.9 b 15.6a
29.1a 5.8c 30.4b
0.02 0.01 0.01
12.5 0 0
6.8 1.2 1.3
9.3 4.2 1.9
0.49 0.18 0.70
Obtained by Chi-square test: values with different letters¼p o 0.05 to show differences in disordered eating behaviors among groups. There was loss of information of two adolescents for purging and of three adolescents for strict dieting. ♦ There was loss of information of one adolescent for purging and strict dieting. ☼ There was loss of information of one adolescent for purging and five adolescents for strict dieting. ξ There was loss information of six adolescents for purging and 4 adolescents for strict dieting. n
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Table 4 Prevalence ratio, confidence interval of 95% and proportional attributable risk for association between disordered eating behaviors among adolescents and adults living in the same household by adults' sex and age group. Duque de Caxias-RJ, Brazil, 2005. Disordered eating behavior in adolescents % Disordered eating behavior in adults Binge eating Yes 38.7 No 17.2 Strict dieting or fasting Yes 43.2 No 17.9
PR (CI 95%)
2.25 (1.39–3.63) 1.00 2.41 (1.3–4.36) 1.00
Disordered eating behavior in adult womena Binge eating Yes 32.3 No 15.6 Strict dieting or fasting Yes 50.3 No 16.1
3.12 (1.70–5.75) 1.00
Disordered eating behavior in adult menb Binge eating Yes 53.1 No 18.9
2.81 (1.30–6.08) 1.00
2.07 (1.23–3.49) 1.00
Disordered eating behavior in adults from 19 to 29.9 years olda Binge eating Yes 34.3 1.81 (0.61–5.29) No 18.9 1.00 Strict dieting or fasting Yes 49.9 4.13 (1.13–15.11) No 12.0 1.00 Disordered eating behavior in adults from 30 to 49.9 years olda Binge eating Yes 42.9 2.52 (1.44–4.42) No 17.0 1.00 Strict dieting or fasting Yes 50.0 2.65 (1.37–5.12) No 18.8 1.00 Disordered eating behavior in adults ≥50 years olda Binge eating Yes 6.3 0.44 (0.04–4.39) No 14.1 1.00 Strict dieting or fasting Yes 14.1 0.68 (0.05–8.72) No 20.5 1.00 PR—prevalence ratio; CI 95%—confidence interval of 95%. a Purging behaviors was excluded, because there was not this behavior among adults. b Purging behaviors and strict dieting or fasting were excluded, because there weren´t these behaviors among adults.
thinness (Field et al., 2003); rather, they can be a precipitant factor for the binge eating that arises following repeated excessive food restriction, characterizing the binge eating behaviors. In the present study, the prevalence (3.3%) of purging behaviors in adolescents was lower than that of other disordered eating behaviors we investigated. However, it was no less important, because such behaviors are unacceptable and quite harmful to adolescent health, particularly among underweight adolescents in whom this behavior was more frequent (11.6%). Interestingly, for adults, the prevalence (2.2%) of purging behaviors was greater than the 1% prevalence observed in two similar studies of the South Australian population (Hay et al., 2008; Mitchison et al., 2012). The prevalence of binge eating in females (10.4%) and males (5.3%) in this study was lower than that observed by Siqueira et al. (2005) in adults at frequent shopping centers in five Brazilian
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capitals (13% among women and 12.8% among men). Freitas et al. (2008) also found a much higher prevalence of binge eating (20.6%) in women residents in the city of Rio de Janeiro. However, the prevalence observed for purging behaviors was similar in both studies (about 3%). Both Freitas et al. and Siqueira et al. investigated a population with a higher socioeconomic status than that investigated in the current study which could explain such differences. However, the relationship between socioeconomic status and disordered eating behaviors is not well understood. An inverse association was observed in Ecuadorian adolescents (Power et al., 2008), and in Portuguese adolescents, associations were found to be dependent on sex, being directly associated for girls and inversely associated for boys (Costa et al., 2008). Further, no association was observed in Brazilian adolescents (Dunker et al., 2009). The lower prevalence observed in our study could also be explained by under-reporting, since purging and binging are considered shameful behaviors. However, in our study as well as in the Siqueira et al. (2005) study, the self-report questionnaire was utilized intentionally to minimize any embarrassment or shame that might arise during a face-to-face interview. Despite the high prevalence of disordered eating behaviors among adults, particularly among women, our study demonstrates that the problem occurs on a larger scale among adolescents, regardless of sex. Such results indicate that during adolescence, even males are at risk. Currently, men desire a much leaner and more muscular body than the body they actually have or perceive themselves to have (Pope et al., 2000; Rodgers et al., 2012). The pursuit of muscularity can lead to use of unhealthy, muscleenhancing behaviors whose prevalence is particularly high in boys (Eisenberg et al., 2012). These unhealthy behaviors could then lead to disordered eating behaviors that have been observed in different ethnic groups (Ricciardelli et al., 2007). Although the prevalence of disordered eating behaviors among adults was meaningful, findings from this study also suggest that adults living in the same household as an adolescent could influence that adolescent to develop the same behavior. In fact, the presence of binge eating and strict dieting or fasting in adults doubled the risk that adolescents living in the same household would exhibit the same behavior in accordance with the findings of Yanez et al. (2007), who found that girls whose mothers demonstrated unhealthy attitudes about eating had three times higher the risk of developing the same behavior than those whose mothers did not demonstrate such attitudes. In our study, we also found that among adolescents who lived with women reporting binge eating and the practice of strict dieting, the prevalence of these behaviors was approximately three times greater than that among the adolescents who lived with women who did not report these behaviors. These results concur with the findings of Sampei et al. (2009), who observed that 33.5% of Caucasian adolescents and 22.1% of Japanese– Brazilian adolescents were motivated by their mothers to engage in strict dieting. In a Spanish study Canals et al. (2009) also found significant associations between mothers' weight loss behaviors and disordered eating behaviors in their daughters. According to our results, male adults also seem to influence adolescents' eating practices: the presence of an adult man engaging in binge eating at home almost tripled the prevalence of this behavior in adolescents in the same household. The findings of our study in combination with the relevant literature (Adami-Lauand and Ribeiro, 2011) support the proposition that the psychodynamics of family interaction is an important factor in determining the development and maintenance of eating disorders. Indeed adult family members who have excessive concern with dieting and weight may negatively affect the development and maintenance of eating disorders in their offspring. Among family factors, emphasis is frequently placed on psychoanalytic viewpoints
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and genetic predisposition. From a psychoanalytic perspective, abnormal mother–daughter relationships are considered to underlie the later development of eating disorders (Betancourt et al., 2007). Further, one longitudinal genetic study (Strober et al., 2000) showed that, in female relatives of anorexic and bulimic probands, the relative risks were 11.3 and 12.3 for the full syndrome of anorexia nervosa and 4.2 and 4.4 for the full syndrome of bulimia nervosa, respectively. The authors then argued that anorexia nervosa and bulimia nervosa are indicative of at least some sharing of familial genetics. Currently, studies estimate that the heritability of eating disorders varies from 40% to 60% (Trace et al., 2013). The findings of all of these studies have contributed to the interpretation of the current work. It is important to address the limitations of this study. Adult participants were randomly chosen and the respondent in the same household was not required to be the adolescent's parent, thus generalization of findings to association with adolescent's parent is limited. However, among the 1085 households evaluated, 32.1% had a woman without a partner (single or divorced) as the head of the household, 37% included children aged from 6 to 30 months, and fewer than 0.5% had more distant relatives living together (data not shown). This allows us to conclude that the adult respondent was most often directly related to the adolescent. Moreover, the method applied in this study allowed us to identify the possible influence of older siblings, since the association between the practice of strict dieting or fasting among young adults aged 19–29 years (unlikely to be parents of teenagers) and the same behavior in adolescents was also significant. Additionally the cross-sectional study design does not permit establishment of causality of the associations between the disordered eating behavior in adults and adolescents. It is possible that the adults could be influenced by the adolescents. Nevertheless, we believe that the reverse is more likely, since in general, adolescents follow their elders' example (Rodgers and Chabrol, 2009). It is important to stress that diagnosis of eating disorders is only possible through clinical interviewing. Thus, this study does not claim to diagnose eating disorders, but rather to determine the risk factors for the development of these disorders in adolescent and adult residents of an area where the majority of residents are of lower socioeconomic status, because such behaviors have been scarcely investigated in this population. So, this study was also hindered by the fact that the questions used to assess disordered eating behaviors were simplistic and did not encompass the full spectrum of eating disorder symptomatology. However, although the questionnaire was comparatively short and simple, the questions addressed important topics relevant to the primary risk factors for eating disorders. The reproducibility of these questions was considered moderate to excellent in a previous study using data from Brazilian adolescents (Ferreira and Veiga, 2008a). Moreover, this simplified approach is appropriate for tracking the issue in epidemiological studies, particularly in people from lower-income social backgrounds with low levels of education, similar to the population investigated in this study, where long and complex questionnaires could be difficult to understand and accurately complete. We conclude that the prevalence of disordered eating behaviors among adolescents is high and that the presence at home of adults with disordered eating behaviors may influence adolescents to acquire similar behaviors. Therefore, adults should be educated about the important role they may play in shaping eating behaviors in adolescents. They should also be informed about interventions aimed at the prevention and control of disordered eating behaviors in adolescents. In both clinical practice and as part of public health initiatives, such interventions should be directed toward both adolescents and the adults with whom they live aiming to be increasingly effective.
References Adami-Lauand, C.B., Ribeiro, R.P.P., 2011. A herança transgeracional nos transtornos alimentares: algumas reflexões. (Transgenerational inheritance in eating disorders: some reflections). Psicologia USP 22, 927–942. Alves, E., Vasconcelos, F.A.G., Calvo, M.C.M., Neves, J., 2008. Prevalência de sintomas de anorexia nervosa e insatisfação com a imagem corporal em adolescentes do sexo feminino do Município de Florianópolis, Santa Catarina, Brasil (Prevalence of symptoms of anorexia nervosa and dissatisfaction with body image among female adolescents in Florianópolis, Santa Catarina State, Brazil). Cadernos de Saúde Pública 24, 503–512. American Psychiatric Association, 1994. Diagnostic and Statistical Manual of Mental Disorders DSM-IV. Washington, DC. Babio, N., Canals, J., Pietrobelli, A., Pérez, S., Arija, A., 2009. A two-phase population study: relationships between overweight, body composition and risk of eating disorders. Nutrición Hospitalaria 24, 485–491. Beckett, L.A., Scherr, P.A., Evans, D.A., 1992. Population prevalence estimates from complex samples. Journal of Clinical and Epidemiology 45, 393–402. Benedikt, R., Wertheim, E.H., Love, A., 1998. Eating attitudes and weight loss attempts in female adolescents and their mothers. Journal of Youth and Adolescence 27, 43–57. Betancourt, L., Rodríguez Guarín, M., Gempeler Rueda, J., 2007. Interacción madrehijo, patrones de apego y su papel en los trastornos del comportamiento alimentario. Universitas Médica 48, 261–276. Canals, J., Sancho, C., Arija, M.V., 2009. Influence of parent's eating attitudes on eating disorders in school adolescents. European Child & Adolescent Psychiatry 18, 353–359. Costa, C., Ramos, E., Severo, M., Barros, H., Lopes, C., 2008. Determinants of eating disorders symptomatology in Portuguese adolescents. Archives of Pediatrics & Adolescent Medicine 162, 1126–1132. Cumella, E.J., Kally, Z., 2008. Comparison of middle-age and young women in patients with eating disorders. Eating and Weight Disorders 13, 183–190. de Onis, M., Onyango, A.W., Borghi, E., Siyam, A., Nishida, C., Siekmann, J., 2007. Development of a WHO growth reference for school-aged children and adolescents. Bulletin of the World Health Organization 85, 660–667. Derenne, J.L., Eugene, V.B., 2006. Body image, media, and eating disorders. Academic Psychiatry 30, 257–261. Dunker, K.L.L., Fernandes, C.P.B., Carreira Filho, D., 2009. Influência do nível socioeconômico sobre comportamentos de risco para transtornos alimentares em adolescentes. (Socioeconomic influence on eating disorders risk behaviors in adolescents). Jornal Brasileiro de Psiquiatria 58, 156–161. Eddy, K.T., Celio Doyle, A., Hoste, R.R., Herzog, D.B., le Grange, D., 2008. Eating disorder not otherwise specified in adolescents. Journal of the American Academy of Child and Adolescent Psychiatry 47, 156–164. Eisenberg, M.E., Wall, M., Neumark-Sztainer, D., 2012. Muscle-enhancing behaviors among adolescent girls and boys. Pediatric 130, 1019–1026. Fernandez-Aranda, F., Krug, I., Granero, R., Ramón, J.M., Badia, A., Gimenez, L., Solano, R., Collier, D., Karwautz, A., Treasure, J., 2007. Individual and family eating patterns during childhood and early adolescence: an analysis of associated eating disorder factors. Appetite 49, 476–485. Ferreira, J.E.S., Veiga, G.V., 2008a. Confiabilidade (teste-reteste) de um questionário simplificado para avaliar comportamentos de risco para transtornos alimentares em adolescentes. (Test-retest reliability of a simplified questionnaire for screening adolescents with risk behaviors for eating disorders in epidemiologic studies). Revista Brasileira de Epidemiologia 11, 393–401. Ferreira, J.E.S., Veiga, G.V., 2008b. Eating disorder risk behavior in Brazilian adolescents from low socioeconomic level. Appetite 51, 249–255. Field, A.E., Camargo, C.A., Taylor, C.B., Berkey, C.S., Roberts, S.B., Colditz, G.A., 2001. Peer, parent, and media influences on the development of weight concerns and frequent dieting among preadolescent and adolescent girls and boys. Pediatrics 107, 54–60. Field, A.E., Austin, S.B., Taylor, C.B., Malspeis, S., Rosner, B., Rockett, H.R., 2003. Relation between dieting and weight change among preadolescents and adolescents. Pediatrics 112 (Suppl. IV), 900–906. Field, A.E., Austin, S.B., Striegel-Moore, R., Taylor, C.B., Camargo, C.A., Laird, N., Colditz, G., 2005. Weight concerns and weight control behaviors of adolescents and their mothers. Archives of Pediatrics & Adolescent Medicine 159, 1121–1126. Freitas, S.R., Appolinário, J.C., Souza, A.M., Schieri, R., 2008. Prevalence of binge eating and associated factors in a Brazilian probability sample of midlife women. International Journal of Eating Disorders 41, 471–478. Grave, R.D., 2011. Eating disorders: progress and challenges. European Journal of Internal Medicine 22, 153–160. Hay, P.J., Mond, J., Buttner, P., Darby, A., 2008. Eating disorder behaviors are increasing: findings from two sequential community surveys in South Australia. PLoS ONE 3, 1–5. Hesse-Biber, S., Leavy, P., Quinn, C.E., Zoino, J., 2006. The mass marketing of disordered eating and eating disorders: the social psychology of women, thinness and culture. Womens's Studies International Forum 29, 208–224. Hill, A.J., Franklin, J.A., 1998. Mothers, daughters and dieting: investigating the transmission of weight control. British Journal of Clinical Psychology 37, 3–13. Instituto Brasileiro de Geografia e Estatística, 2010. Pesquisa de Orçamentos Familiares 2008–2009. Antropometria e estado nutricional de crianças, adolescentes e adultos no Brasil (Household Budget Survey 2008–2009). (Anthropometry and nutritional status of children, adolescents and adults in Brazil). Instituto Brasileiro de Geografia e Estatística, Rio de Janeiro. Retrieved from 〈http://www.ibge.gov.br〉.
J.E.d.S. Ferreira et al. / Psychiatry Research 210 (2013) 612–617
Kjelsås, E., Bjørnstrøm, C., Götestam, K.G., 2004. Prevalence of eating disorders in female and male adolescents (14–15 years). Eating Behaviors 5, 13–25. Lwanga, S.K., Lemeshow, S., 1991. Sample Size Determination in Health Studies: A Practical Manual. World Health Organization, Geneva. May, A.L., Kim, J.Y., McHale, S.M., Crouter, A., 2006. Parent–adolescent relationships and the development of weight concerns from early to late adolescence. International Journal of Eating Disorders 39, 729–740. Mitchison, D., Hay, P., Slewa-Younan, S., Mond, J., 2012. Time trends in population prevalence of eating disorder behaviors and their relationship to quality of life. PLoS ONE 7, 1–7. Nunes, M.A., Barros, F.C., Anselmo, O.M.T., Camey, S., Mari, J.D., 2003. Prevalence of abnormal eating behaviors and inappropriate methods of weight control in young women from Brazil: a population-based study. Eating and Weight Disorders 8, 100–106. Nunes, M.A., Olinto, M.T., Camey, S., Morgan, C., Mari, J.J., 2006. Abnormal eating behaviors in adolescent and young adult women from southern Brazil: reassessment after four years. Social Psychiatry Epidemiology 41, 951–956. O’Connor, M., Simmons, T., Cooper, M., 2003. Assumptions and beliefs, dieting, and predictors of eating disorder-related symptoms in young women and young men. Eating Behaviors 4, 1–6. Ogden, J., Steward, J., 2000. The role of the mother–daughter relationship in explaining weight concern. International Journal of Eating Disorders 28, 78–83. Pope Jr., H.G., Gruber, A.J., Mangweth, B., Bureau, B., deCol, C., Jouvent, R., Hudson, J.I., 2000. Body image perception among men in three countries. American Journal of Psychiatry 157, 1297–1301. Portela de Santana, M.L., da Costa Ribeiro Junior, H., Mora Giral, M., Raich, R.M., 2012. Epidemiology and risk factors of eating disorder in adolescence: a review. Nutrición Hospitalaria 27, 391–401. Power, Y., Power, L., Canadas, M.B., 2008. Low socioeconomic status predicts abnormal eating attitudes in Latin American female adolescents. Eating Disorders 16, 136–145. Preti, A., Girolamo, G., Vilagut, G., Alonso, J., Graaf, R., Bruffaerts, R., Demyttenaere, K., Pinto-Meza, A., Haro, J.M., Morosini, P., ESEMeD-WMH Investigators, 2009. The epidemiology of eating disorders in six European countries: results of the ESEMeD-WMH project. Journal of Psychiatric Research 43, 1125–1132. Ricciardelli, L.A., McCabe, M.P., Williams, R.J., Thompson, K.J., 2007. The role of ethnicity and culture in body image and disordered eating among males. Clinical Psychology Review 27, 582–606. Rodgers, R., Chabrol, H., 2009. Parental attitudes, body image disturbance and disordered eating amongst adolescents and young adults: a review. European Eating Disorders Review 17, 137–151. Rodgers, R.F., Ganchou, C., Franko, D.L., Chabrol, H., 2012. Drive for muscularity and disordered eating among French adolescent boys: a sociocultural model. Body Image 9, 318–323.
617
Salles-Costa, R., Pereira, R.A., Vasconcellos, M.T.L., Veiga, G.V., Marins, V.M.R., Jardim, B.C., Gomes, F.S., Sichieri, R., 2008. Associação entre fatores socioeconômicos e insegurança alimentar: estudo de base populacional na Região Metropolitana do Rio de Janeiro, Brasil (Association between socioeconomic factors and food insecurity: a population-based study in the Rio de Janeiro metropolitan area, Brazil). Revista de Nutrição 21 (Supl.), 99s–109s. Sampei, M.A., Sigulem, D.M., Novo, N.F., Juliano, Y., Colugnati, F.A.B., 2009. Eating attitudes and body image in ethnic Japanese and Caucasian adolescent girls in the city of São Paulo, Brazil. Jornal de Pediatria 85, 122–128. Sancho, C., Arija, A., Asorey, O., Canals, J., 2007. Epidemiology of eating disorders: a two year follow up study in an early adolescent school population. European Child & Adolescent Psychiatry 16, 495–504. Shomaker, L.B., Furman, W., 2009. Interpersonal influences on late adolescent girls' and boys' disordered eating. Eating Behaviors 10, 97–106. Siqueira, K.S., Appolinário, J.C., Schieri, R., 2005. Relationship between binge-eating episodes and self-perception of body weight in a nonclinical sample of five Brazilian cities. Revista Brasileira de Psiquiatria 27, 290–294. Smink, F.R.E., Hoeken, D.V., Hoek, H.W., 2012. Epidemiology of eating disorders: incidence, prevalence and mortality rates. Current Psychiatry Reports 14, 406–414. Sousa, M.H., Silva, N.N., 2003. Estimativas obtidas de um levantamento complexo (Estimates from a complex survey). Revista de Saúde Pública 37, 662–670. Strober, M., Freeman, R., Lampert, C., Diamond, J., Kaye, W., 2000. Controlled family study of anorexia nervosa and bulimia nervosa: evidence of shared liability and transmission of partial syndromes. American Journal of Psychiatry 157 (3), 393–401. Trace, S.E., Baker, J.H., Peñas-Lledó, E., Bulik, C.M., 2013. The genetics of eating disorders. Annual Review of Clinical Psychology 9, 589–620. Vale, A.M.O., Kerr, L.R.S., Bosi, M.L.M., 2011. Risk behaviors for eating disorders among female adolescents from different social strata in the Brazilian Northeastern. Ciência & Saúde Coletiva 16, 121–132. Vilela, J.E.M., Lamounier, J.A., Dellaretti, M.A., Barros Neto, J.R., Horta, G.M., 2004. Anorexia nervosa, bulimia nervosa, inappropriate eating behaviors, epidemiology. Pediatrics 80, 49–54. Wertheim, E.H., Martin, G., Prior, M., Sanson, A., Smart, D., 2002. Parent influences in the transmission of eating and weight related values and behaviors. Eating Disorders 10, 321–334. World Health Organization, 1998. Yanez, A.M., Peix, M.A., Atserias, N., Arnau, A., Brug, J., 2007. Association of eating attitudes between teenage girls and their parents. International Journal of Social Psychiatry 53, 507–513.