DIETING, DIETARY RESTRAINT, AND BINGE EATING DISORDER AMONG OVERWEIGHT ADOLESCENTS IN TURKEY Murat Bas, Nuray Bozan, and Nevin Cigerim ABSTRACT
The purpose of this study was to determine the relationship among dieting, dietary restraint, disinhibition, hunger, and binge eating among overweight adolescent girls. Participants were 743 overweight adolescent girls between 16 and 19 years of age. The mean BMI was 24.9±0.8 kg/m^ in the low-restraint group and 25.1 ±0.8 kg/m^ in the high-restraint group (p < 0.05).Twenty percent of participants in the low-restraint group and 72% of those in the highrestraint group followed weight management practices for losing weight. The mean total TFEQ score was 21.5±7.8 for chronic dieters and 25.5±8.7 for nonchronic dieters. Chronic dieter participants had significantly lower scores than non-chronic dieters (p < 0.05). Findings indicate that overweight adolescents (dieting 5-10 times or more than 10 times in the past year) reported higher disinhibition and hunger scores than others (no dieting in the past year). Also, adolescents with BED reported significantly higher scores of disinhibition and hunger than did adolescents with non-BED. Conversely, overweight adolescents with BED showed significantly higher cognitive restraint scores than did adolescents with non-BED. In sum, high scores on restraint, hunger, and disinhibition of overweight 'adolescent girls as measured by the TFEQ, are associated with low self-esteem, high social physique anxiety, and high trait anxiety.
INTRODUCTION
Eating disorders are characterized by severe disturbances in eating behavior. During the past 20 years, a great deal of attention has been devoted to eating disorders in women. The number of publications on anorexia nervosa and binge eating disorder has grown exponentially during this period. According to a report from the World Health Organization (1998), obesity is increasing worldwide at an alarming rate in both developed and developing countries. This is a matter of concem Reprint requests should be sent to: Murat Bas, Ph.D., Baskent University, Health Sciences Faculty, Department of Nutrition and Dietetics, Eskisehir Yolu 2O.km, Baglica Kampusu, 06530, Ankara, TURKEY. E-mail:
[email protected] ADOLESCENCE, Vol. 43, No. 171, Fall 2008 Libra Publishers, Inc., 3089C Clairemont Dr., PMB 383, San Diego, CA 92117
because obesity increases the risks for many serious illnesses, such as diabetes, mellitus, hypertension, dyslipedemia, coronary artery disease, and some forms of cancer (Solomon & Manson, 1997). Further, the findings of a recent study (Croll, Neumark-Sztainer, Story, & Ireland, 2002) suggest that disordered eating is very prevalent among youth, with at least one of the following—fasting, skipping meals to lose weight, use of diet pills, vomiting, taking laxatives, smoking cigarettes, and binge eating—being recently reported by a staggering 56% of 9th-grade females and 28% of 9th-grade males. Reports of dieting, fear of fatness, body image concerns, and weight loss attempts, as well as cases of more serious eating disorders have been documented in children as young as seven years of age (Ricciardelli & McCabe, 2001). Accordingly, these authors identify several potential risk factors grouped into five broad categories. Based on this analysis the present study included measures of demographics (age, degree of obesity), weight history (age of obesity onset), social/environmental infiuences (peer interpersonal relationships), cognitive factors (body image dissatisfaction, self-esteem) and eating behavior (dieting, binge eating). The TFEQ was developed by Sunkard and Messick in 1985; it consists of three different scales: restraint, disinhibition, and susceptibility to hunger. The restraint scale is designed to assess only cognitive eating restraint. It has been hypothesized that social class differences in eating behaviors and cognitions, such as dietary restraint, might account for part of the gradient in overweight and obesity (Sobel & Stunkar, 1989; Wardle & Griffith, 2001). Restraint theory (Herman & Mack, 1975; Herman & Polivy, 1984) was developed as a way to understand the psychological basis of eating behaviors and disorders, including obesity and anorexia. Restrained eaters are individuals who consciously restrict their dietary intake as a means of losing or maintaining weight (Polivy & Herman, 1985). Although dietary restraint is recognized as an important risk variable, a clearer understanding of the association between dietary restraint and other personal characteristics is needed before decisions for prevention can be made. Recently Carter, Stewart, Dunn, and Fairburn (1997) demonstrated that a school-based eating disorder prevention program, designed to reduce dietary restraint in schoolgirls, did more harm than good. Fairburn et al. (1998) investigated dieting vulnerability factors in a community-based study and found that, among other things, childhood obesity and exposure to negative comments about weight, shape or eating were more prevalent among bulimia cases and in binge eaters. Current findings point to a direct association in the increase in BMI with concems about eating, weight, and shape with dietary restraint 636
and with binge eating. Moreover, half the subjects who reported binge eating were above the 90th percentile for BMI. Hence, further strength is added to the suggestion that being overweight might predispose persons to or be a consequence of disturbed eating (Fombonne, 1995). Clearly, development of self-esteem as a protective factor against body dissatisfaction and disordjered eating was strongly identified in the late 1980s and early 1990s (O'dea, 2004). Because there is evidence that obese children and adolescents who are binge eaters are different from the obese non-binge eaters in self-esteem and in a broad range of eating-related characteristics (Decaluwe, Braet, & Fairburn, 2003), special strategies that focus on the problems of obese binge eaters might be warranted. McjGuire et al. (2001) found that increases in dietary restraint in the weight management period were related to decrease in BW. An increase in dietary restraint (Fl score) is often related to a decrease in disinhibition (F2 score) (Dykes, Brunner, Martikainen, & Wardle, 2004¡). The present study had three aims. The first was to examine the relationship among dietary restraint, disinhibition, and hunger as measured by the three-factor eating questionnaire and dieting; the second was to investigate binge eating in this group; and the third was to examine the link between dietary restraint, disinhibition, hunger, and binge eating. METHOD
Participants A total of 758 female adolescents between 16 and 19 years of age (mean age 16.5, standard deviation 1.4 years) were asked to participate in the study. Of the 758 distributed surveys, 15 were not returned or had missing information; therefore 743 surveys were used for the analyses. Measurement and data collection were conducted during a 6-month period between September and February 2006. Body mass index. BMI (weight in kilograms divided by height in meters squared) was calculated for each participant to obtain a single measure of body size. The calculation was based on self-reported height and weight provided by participants on a general information sheet. Gender- and age-specific I definitions for underweight, normal weight, and overweight were based on growth charts from the Centers for Disease Control and Prevention (Kuczmarski, Ogden, GrummerStrawn, Flegal, Guo, Weij Mei, & Curtin, 2000). For the present study, subjects classified as underweight (BMI < 15th percentile) or average weight (BMI 15th to < 85th percentile) were grouped as "non-over637
weight," and those moderately overweight (BMI 85th to < 95th percentile) or very overweight (BMI > 95th percentile) were grouped together as "overweight" (Neumark-Sztainer, Wall, Eisenberg, Story, & Hannan, 2006). Dieting status. Dieting for weight-loss purposes was assessed by the question: "How often have you gone on a diet during the last year?" By diet, we mean changing the way you eat so you can lose weight." Response options included: "never," "1-4 times," "5-10 times," "more than 10 times," and "I am always dieting." Adolescents who reported dieting five or more times in a year were coded as "chronic dieters" (Crow, Eisenberg, Story, & Neumark-Sztainer, 2006). Weight control behaviors. Healthy, unhealthy, and extreme weightcontrol behaviors were assessed with the question: "Have you done any ofthe following in order to lose weight or keep from gaining weight during the past year? (yes or no for each method)." Responses categorized as healthful weight control behaviors included (1) exercised, (2) ate more fruit and vegetables, (3) ate less high-fat foods, and (4) ate less sweets. Unhealthful weight-control behaviors included (1) fasted, (2) ate very little food, (3) used a food substitute (powder or a special drink), (4) skipped meals, and (5) smoked more cigarettes. Extreme weight control behaviors included (1) took diet pills, (2) made myself vomit, (3) used laxatives, and (4) used diuretics. Percentages of respondents using at least one of the behaviors within the three categories of^healthful, unhealthful, or extreme behaviors were circulated (Neumark-Sztainer, Wall, Eisenberg, Story, & Hannan, 2006). Binge eating disorder (BED) status. BED status was assessed using three items from the Questionnaire on Eating and Weight Patterns, which had been used in community and weight treatment-seeking populations to vahdate the BED diagnostic criteria for DSM-IV and to determine the presence of BED. Participants were asked to rate the presence and fi-equency of overeating and feelings of loss of control over their eating during the past 6 months. Participants were classified as having no bingeing (no periods of overeating or feelings of loss of control), some bingeing (binge episodes and feelings of loss of control less than 2 days per week), or probable BED (binge episodes and feelings of loss of control at least 2 days per week for the past 6 months). (Spitzer, Devlin, Walsh, Hasin, Wing, Marcus, Stunkard, Wadden, Yanowski, Agras, Mitchell, & Nonas, 1992; American Psychiatric Association, 1994).
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Instruments Three Factor Eating Questionnaire (TFEQ). Eating behavior was characterized using a Turkish translation of the TFEQ (Stunkard & Messick, 1985). The TFEQ consists of 49 questions representing three different factors relevant to human eating behavior. The first factor (Fl) measures cognitive restrained eating: control of food intake by thought and will power. T?he second factor (F2) represents disinhibition: an incidental inability to resist eating cues or inhibition of dietary restraint (Fl), and emotional eating. The third factor (F3) examines the subjective feeling of general hunger. The factors are randomly divided among the questions. The maximum score for Fl, F2, and F3 are respectively 21, 14, and 14. The reliability of EAT-26 was also determined by a pilot study with 50 university students. The internal consistency (Cronbach's alpha) of EAT-26 was .83 and its interclass correlation coefficient was' .97 in the pilot study. Rosenberg Self-Esteem 'Scale. The 10-item Rosenberg Self-esteem Scale (Rosenberg, 1965) was included. Additional questions, using tbe same four-point response format (strongly agree-strongly disagree) addressed contentment with social life, feeling sexually attractive, and wearing fashionable clothes. Reliability and validity ofthe instrument for Turkish adolescents were determined in a recent study carried out by Cuhadaroglu (1986). Social Physique Anxiety Scale. The Social Physique Anxiety Scale (SPAS) was originally designed to determine the degree to which people become anxious about the real or perceived evaluation of their physique by others (Hart, Leary, & Rejeski 1989). The SPAS is a selfreport inventory wherein participants respond to 12 items on a 5-point Likert scale. The reliability and validity evidence of SPAS for Turkish university students was determined by Mülazimoglu & A§çi (unpublished data). The test-retest reliability (Cronbach's alpha) ofthe social physique anxiety scale was 0.92 for females and 0.76 for males. Internal consistency for 12 items was 0.89 for females and 0.86 for males. State-Trait Anxiety Inventory. The State-Trait Anxiety Inventory (STAI) is a self-report instrument developed by Spielberger, Gorsuch, and Lushene (1970) to measure the subjective level of anxiety botb in special situations and in general. STAI was standardized by Oner and Le Compte (1985) for the Turkish population and the mean values in the normative study ranged from 36 to 31, with higher scores indicating a higher level of anxiety. Intemal consistency and test-retest reliability ofthe trait form ofthe STAI were .87 and .86, respectively. The criterion and construct validity analysis supported the validity of STAI (Oner & Le Compte, 1985)'; 639
Statistical analysis. Data were analyzed using student's paired and unpaired i-test, chi-square test, and simple correlations through SPSS 11.5 Due to the number of statistical analyses, p < 0.05 was used to indicate significance. RESULTS
Demographic characteristics and weight-control behavior of participants in the low-restraint control and high-restraint group is presented Table 1. The mean BMI was 24.9±0.8 kg/m^ in the high-restraint group (p < 0.05). Twenty percent of participants in the low-restraint group and 72.0% of participants in the high-restraint group followed weight management practices for losing weight. Participant in the high-restraint group reported high rates of dieting frequency in the past year (11.8% of participants in the low-restraint group and 55.4% of participants in the high-restraint group reported dieting 5-10 times in the past year). In addition, participants in the high-restraint group reported a higher percentage ofthe unhealthful weight control behaviors tban did participants in the low-restraint group, such as skipping meals, eating little, vomiting, using diet pills or laxatives, smoking cigarettes, and fasting. (See Table 1.) The scores for the questionnaire on TFEQ, ESES, RSES, SPAS, and STAI of participants in the low-restraint control and high-restraint group are presented in Table 2. Participants in the high-restraint group displayed a significantly higher TFEQ [F (1, 29) = 7.009, p < 0.05] and restraint scores [F (1, 279) = 25.273, p < 0.05] than participants in the low-restraint group. In the high-restraint group, the scores on self-esteem [F (1, 279) = 18.049, p < 0.05] and social physique anxiety [F (1, 279) = 0.001, p < 0.05] were significantly higher than in the low-restraint group (p < 0.05). Of the 743 overweight adolescent, 175 were identified as the BED group and 568 were not. The scores for the questionnaires on general current psychological status and eating behavior are presented in Table 3. Participants in the BED group had roughly more social physique anxiety and more were anxious than participants in the non-BED group (p < 0.05). The scores for restraint [F (1, 279) = 7.624, p < 0.05], disinhibition [F(l, 279) = 38.713, p < 0.05], and hunger [F (1, 279) = 2.723, p < 0.05] were significantly different for the two groups (p < 0.05). The mean total TFEQ score was 21.5±7.8 for chronic dieters and 25.5±8.7 for nonchronic dieters. Chronic dieters had significantly lower scores than nonchronic dieters [F (1, 279) = 11.034, p < 0.05]. 640
Table 1 Demographic Characteristics and Weight Control Behaviors of Overweight Adolescents by High-Restraint and Low-Restraint Scores
Characteristic Age (yr) Height (cm) Weight (kg) BMI (kg/rn^)* Dieting Frequency*^ Never 1-4 times 5-10 times More than 10 times Always on diet Weight Control Behaviors'^ No behavior Healthy weight control Unhealthy weight control
Low-Restraint Group" (n = 110)
High-Restraint Group" (n = 168)
P
16.6±1.4 165.9±8.3 54.4 ±10.4 24.9±0.8
16.4±1.3 164.3±7.5 57.6±8.2 25.1 ±0.8
0.091 0.105 0.000* 0.022*
88 (80.0%) 7 (6.4%) 13(11.8%) 2(1.8%) -
47 (28.0%) 15(8.9%) 93 (55.4%) 7 (4.2%) 6 (3.6%)
u.uuu
88 (80.0%) 15(13.6%) 7 (6.4%)
47 (28.0%) 74 (44.0%) 47 (28.0%)
n nnn* u.uuu
^BMI = body mass index. 'Scores of 0-5 on the TFEQ restraint scale. "Scores of 13-21 on the TFE|Q restraint scale. 'Past year. 'Significant difference (p
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