Dietary restraint, attributional styles for eating, and preloading effects

Eating Behaviors 1 (2000) 63 ± 78

Dietary restraint, attributional styles for eating, and preloading effects Ken J. Rotenberg a,*, Darlene Flood b a

Department of Psychology, Keele University, Staffordshire ST5 5BG, UK Department of Psychology, Lakehead University, Thunder Bay, Canada P7B 5EI

b

Abstract A total of 319 undergraduates completed the Restraint Scale and an Eating Attributional Style Questionnaire (EASQ). Subsequently, 101 female students participated in the classic preloading experiment. The results indicated that restrained eating was associated with an external locus of control attribution style, particularly for indulgent food consumption (ELCifc). Partial preloading effects for Restraint were found: The amount consumed increased as a function of Restraint in the preload condition. A more complete pattern of preloading was found for the ELCifc attribution style. In addition, the relationship between Restraint and food consumed in the preload condition was no longer significant with the ELCifc attribution style partialled out. The findings supported the hypotheses that: (a) restrained eaters display an external attribution style of learned helplessness and (b) related cognitions serve as a cause of preloading effects. D 2000 Elsevier Science Ltd. All rights reserved. Keywords: Restraint; Attribution style; Preloading

1. Introduction Over the past two decades, there has been a dramatic increase in research on dietary restraint (Allison, 1995; Ruderman, 1986) that has been fostered by concern over the increasing prevalence in Western society of dieting and clinical eating disorder syndromes, such as bulimia (see Brownell & Rodin, 1994). Dietary restraint refers to the extent to which individuals are concerned with their weight and attempt to control it by dieting. An extensive body of researchers has been dedicated to examining the factors that affect the extent to which * Corresponding author. Tel.: +44-1782-583669; fax: +44-1782-583387. E-mail address: [email protected] (K.J. Rotenberg). 1471-0153/00/$ ± see front matter D 2000 Elsevier Science Ltd. All rights reserved. PII: S 1 4 7 1 - 0 1 5 3 ( 0 0 ) 0 0 0 0 5 - 2

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restrained eaters (those high on dietary restraint) and unrestrained eaters (those low on dietary restraint) consume food. Preloading is one factor that affects food consumption as a function of dietary restraint. Consuming an apparently high calorie food serves to disinhibit food consumption in restrained eaters (i.e., increases food consumption) and to inhibit food consumption in unrestrained eaters (i.e., decreases food consumption) (Herman & Mack, 1975; Hibscher & Herman, 1977; Ruderman & Christensen, 1983). Negative emotional states (e.g., depression and anxiety) have been found to similarly disinhibit food consumption in restrained eaters and inhibit food consumption in unrestrained eaters (Baucom & Aitken, 1981; Frost, Goolkasian, Ely, & Blanchard, 1982; Herman & Polivy, 1975; Ruderman, 1985a; see the review by Ruderman, 1986). Statistically significant effects of preloading and negative emotional states have not been found by all researchers, however (see Dritschel, Cooper, & Charnock, 1992; Jansen, Oosterlaan, Merckelbach, & van de Hoot, 1988; Steere & Cooper, 1993). Heatherton, Herman, and Polivy (1991) found that ego threats (failure on a spatial perception task or threat of giving a talk), but not physical threat (shock), serve as disinhibitors of food consumption in restrained eaters (see also Heatherton, Herman, & Polivy, 1992; Schotte, 1992). Research on the effects of preloading and negative emotional states have been guided in many studies by Herman and Polivy's (1984) boundary model. According to the model, biological pressures work to maintain consumption within a certain range. The aversive qualities of hunger work to keep consumption above some minimum level, whereas the aversive qualities of satiety work to keep it below some maximum level. The area between the boundaries of hunger and satiety is referred to as the zone of biological indifference. Herman and Polivy (1984) proposed that this zone of biological indifference is wider in restrained than unrestrained eaters, with restrained eaters requiring greater food deprivation to experience hunger and greater food consumption to experience satiety. In addition, the researchers proposed that there was a dietary boundary that was not physiological, but psychological, and consisted of cognitive rules for limiting caloric intake to maintain a desirable weight. For the restrained eater, the diet boundary falls within their zone of biological indifference and is closer to the zone of hunger than satiety. When restrained eaters have not consumed a preload they eat only a small amount of food because anything more would breach their diet boundary. After a preload, however, restrained eaters believe that they have violated the diet boundary and see no further reason to restrict further food consumption, resulting in a binge. Herman and Polivy (1984) referred to this pattern as the ``what-the-hell-effect.'' The role of cognitive rules for food consumption identified in Herman and Polivy's (1984) theory has prompted some researchers to search for the cognitions associated with restrained eating and, in particular, the cognitive mediators of preloading effects. Some studies reveal that preloading effects occur when restrained eaters were mislead to believe that they have eaten high calorie foods (Polivy, 1976; Spencer & Fremouw, 1979) and weighed more than their actual weight (McFarlane, Polivy, & Herman, 1998). The findings have been interpreted as supporting the conclusion that preloading effects are cognitively mediated. Ruderman (1985b) found that dieters were prone to irrational thinking, especially about food and eating that serve to increase their susceptibility to disinhibited eating or

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binges once their diets were broken. In contrast, Jansen, Merckelbach, Oosterlann, Tuiten, and van den Hout (1988) did not find appreciable differences between restrained and unrestrained eaters after a preload in their self-report of disinhibitory thoughts about food. In addition, Heatherton and Baumeister (1991) proposed that the cognitive processes associated with the escape from self-awareness served to disinhibit food consumption in restrained eaters as a result of a preload. The present research was designed to examine the cognitive processes underlying dietary restraint and related preloading effects. There is considerable evidence to suggest that restrained eaters frequently fail to maintain their diets (Carmody, Brunner, & St. Jeor, 1995; Lowe, 1993; Tuomisto, Lappalainen, Hetherington, & Tuomisto, 1994). This is shown by the range of factors (e.g., preloads, negative emotional states) that cause restrained eaters to disinhibit their food consumption and literally ``break their diets'' in experimental settings (as previously cited). It would be reasonable to expect that restrained eaters have established some form of learned helplessness. An extensive body of knowledge has been established regarding learned helplessness attribution styles. The current research is designed to examine whether eating restraint is associated with learned helplessness attribution styles and, in particular, what specific type (model) of learned helplessness attribution style is associated with dietary restraint. The research is guided by the principle that such information is relevant to the interventions designed to assist restrained eaters and individuals displaying related eating disorders. The interventions could include methods intended to modify specific attribution styles in restrained eaters and others with related eating disorders and thereby reduce their learned helplessness. 1.1. External attribution model of learned helplessness Seligman (1975) hypothesized that learned helplessness was the result of individuals' belief that they had little control over important outcomes, and therefore believed that the outcomes of their actions were due to external causes. According to Seligman (1975), individuals who adopted such an ``external'' attribution style were at risk for depression. Meta-analyses of the research have yielded support for that account of depression (see Benassi, Sweeney, & Dufour, 1988). The implications of an external attribution model of learned helplessness to restrained eaters are the following. If restrained eaters develop learned helplessness from the roller-coaster patterns of dieting, then they should believe that their success in eating (i.e., moderation) and their failure (i.e., indulging) are controlled by the environment or circumstancesÐexternal attributions. The preloading effects would arise because restrained eaters view consumption of a preload as a failure, a perception that elicits external attributions, which increases food consumption. Because unrestrained eaters do not view the preload as a failure, nor as one controlled by external causes, they become satiated as a result of the preload and eat less. 1.2. Internalized failure attribution model Another model of the attribution styles of learned helplessness and depression has been advanced by Abramson et al. (Abramson, Metalsky, & Alloy, 1989; Abramson, Seligman, &

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Tesdale, 1978; Alloy & Abramson, 1982). In a revision of Seligman's (1975) original hypothesis, these researchers proposed that, in contrast to nondepressed individuals, depressed individuals attribute their failures to stable, internal, and global causes and attribute their successes to unstable, external, and situational causes. Reviews of research and metaanalyses yield support for this model of learned helplessness (Peterson & Seligman, 1984; Sweeney, Anderson, & Bailey, 1986). The implications of this internal attribution model of learned helplessness to dietary restraint are the following. Because of the learned helplessness arising from the dieting cycle, restrained eaters should attribute their failure to restrain their food consumption (i.e., indulging) to internal, stable, and global causes and attribute their success in restrained eating (i.e., moderation) to external, unstable, and specific causes. Unrestrained eaters should show the opposite pattern in so far as they demonstrate a nonhelplessness attributional style. The implication of this attribution model for the preloading effect rests on the ``abstinence violation effect'' (AVE) that has been applied to various addictions, such as alcohol, smoking, and binge eating (Collins & Lapp, 1991; Curry, Marlatt, & Gordon, 1987; Grilo & Shiffman, 1994; Ruderman & McKirnan, 1984). According to the AVE formulations, an individual who attributes a lapse (a violation of restraint) to internal, stable, and global aspects of self will experience a more intense AVE. The resulting experience of generalized failure by the individual increases his/her perception that he/she is unable to exert control over consumption of the substance (i.e., helplessness), which in turn undermines subsequent attempts to exert control, resulting in another lapse or full blown relapse (see Marlatt, 1985). When applied to restrained eating, the AVE formulations imply that restrained eaters are prone to disinhibit their eating as a result of preloading because they attribute that lapse to internal, stable, and global aspects of self resulting in another lapse (i.e., eating). Some researchers have examined whether dietary restraint is associated with learned helplessness. Carmody et al. (1995) found, in obese and nonobese individuals, that cognitive restraint and disinhibition regarding food consumption was correlated with dietary helplessness, as assessed by the Nutrition Attitude Survey developed by Hollis, Carmody, Connor, Fey, and Matarazzo (1986). It was further found that dietary helplessness was associated with a history of weight fluctuation and weight gain. Green and Saenz (1995) found that exposure to an attractive woman increased food consumption in restrained female eaters. This effect was mediated by the participants' experience of negative affect and reduction in their dieting self-efficacy. In addition, Troop and Treasure (1997) found that women with eating disorders were more likely to report experiencing helplessness during their childhood than did women without eating disorders. Although the aforementioned studies are informative, there remains a gap in knowledge regarding the relation between dietary restraint and attributional styles for food consumption. 1.3. Overview of the present research The present study was carried out in two phases. The first phase was designed to examine whether the external attribution or internalized failure attribution model of learned helplessness of food consumption was linked to dietary restraint. The second

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phase was designed to examine the extent to which that type of learned helplessness attribution style was associated with, and contributed to, classic preloading effects. The majority of studies have demonstrated preloading effects in females and therefore females served as participants in the second phase of the study. It was hypothesized that: (a) dietary restraint would be negatively associated with food consumption in control condition (no preload); (b) dietary restraint would be positively associated with food consumption in the preload condition; and (c) restrained eaters would consume more in preload than no-preload condition whereas unrestrained eaters would consume less in the preload than no-preload condition. 2. Method 2.1. Subjects A total of 319 undergraduate students (207 females and 112 males) who were enrolled in introductory psychology at Lakehead University served as participants in the first phase of the study. Of these, 101 females participated in the second phase of the study regarding preloading effects. The students received credit toward their course for participating in the study. The mean age of the entire sample was 20 years and 8 months, with a standard deviation of 4 years. 2.2. Measures 2.2.1. Restraint Scale This 10-item scale was developed by Herman and Polivy (1980) and includes items to assess the frequency of dieting, obsession over food, and fluctuation in weight. Research has documented that this scale demonstrates acceptable internal consistency with alphas 0.78, high test±retest reliability with r's = 0.70 across 2-year periods (see Klesges, Klem, Epkins, & Klesges, 1991) and validity (see Heatherton, Herman, Polivy, King, & McGree, 1988; Laessle, Tuschl, Kotthaus, & Pirke, 1989). 2.2.2. The Eating Attributional Style Questionnaire (EASQ) This questionnaire was based on the Attributional Style Questionnaire (Peterson et al., 1982) and similar questionnaires used to assess causal attributions for specific psychosocial problems, such as smoking (see Collins & Lapp, 1991; Curry et al., 1987). The questionnaire comprised eight incidents depicting persons eating low-calorie or high-calorie foods that were selected from the food list used by Knight and Boland (1989). Four of the incidents in the EASQ depicted the person as displaying moderation in eating, and they were: (a) having the opportunity of having an all-you-can-eat dessert buffet but eating a fruit salad for dessert; (b) receiving a box of chocolates but only eating two and sharing the rest with friends and family; (c) being at a party and, even though there were favorite foods available, eating some cantaloupe and strawberries; and (d) going to a coffee shop, and even though friends ate donuts, only drinking a cup of coffee. Four of the incidents

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depicted the person as indulging in fattening food, and they were: (a) eating potato chips and pop/soda while watching a movie at home; (b) meeting a friend and eating a Big Mac, large fries, and a large chocolate milkshake; (c) buying favorite candy bars on Halloween and, before the first child arrives, eating them all; and (d) eating two helpings of a Christmas dinner and chocolate cake and ice cream for dessert. In order to answer this scale, the participant was required to imagine that he/she was the protagonist in each incident in the EASQ and then to rate on five-point Likert scales: (a) the extent to which the eating behavior in the incident (e.g., eating the Big Mac, fries, and milkshake) was due to something about you or something about other people or circumstances (locus of control); (b) the extent to which that cause would be present in the future (stability); (c) the extent to which that cause influences only that given eating behavior or influences other life situations (globality); and (d) the extent to which the situation would be important if it happened to him/her (importance). The latter question was not conceptualized as an attributional style but was included as a validity check on the food consumption incidents. It was expected that Restraint would be correlated with ratings of importance because indulgent and moderate food consumption would have greater significance for restrained than unrestrained eaters. 2.3. Procedure In the first phase of the study, the participants were administered the Restraint Scale and the EASQ in groups after their Introductory Psychology class. A matching assignment procedure was employed for the second phase of the study. Pairs of the females that had equivalent Restraint Scale scores were selected from the sample and, from each pair, one member was randomly assigned to the no-preload (control) condition and the other member was assigned to the preload condition. If one from a given pair did not participate, then a female who matched the Restraint score of the missing individual was subsequently selected and assigned to the corresponding condition. In the second phase of the study, individuals were telephoned and asked to take part in a study on how the taste of some food affected the taste of other foods. Individuals who agreed were asked to refrain from eating at least 2 h prior to coming to the experiment. The testing sessions were scheduled for either a mid-morning period (from approximately 10:00 to 12:00 hours) or mid-afternoon period (approximately 12:00 to 16:00 hours). Typically, the participants had eaten one meal between 2 and 4 h prior to the testing session. During the testing session, the participant in the preload condition was required to consume a chocolate milkshake (approximately 5 oz), whereas the participant in the no-preload condition was not given that opportunity (nor was it mentioned). The participant was then engaged in a taste test of three types of cookies, labeled as type A, B, and C. She was instructed to taste the cookies in the specified order (A, B, and then C), eat as many cookies as she wanted to, and then rate the taste of each type of cookie on three rating scales. The cookies weighed 12 g on the average. The participant was left alone in the testing room and given 10 min to eat and rate the cookies. After the taste session was completed, the participant was debriefed about the study and asked to refrain from discussing it with others.

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3. Results 3.1. Characteristics of the scales The alpha coefficient for the Restraint Scale was 0.77, which is very similar to those obtained in other research (i.e., Laessle et al., 1989). The alpha coefficients for the EASQ scales are shown in Table 1 and are similar to those found for broad attributional style scales (Seligman, Abramson, Semmel, & von Baeyer, 1979) and attributional styles for specific psychosocial problems (Collins & Lapp, 1991). The EASQ scales showed acceptable internal consistency, especially when considering the small number of items per scale. The EASQ scales were scored such that greater numbers designate greater internally, stability, globality, and importance. The means and standard deviations of the scales for males and females are presented in Table 1. ANOVAs on the scales yielded two gender differences. Females displayed higher scores on Restraint, F(1, 317) = 23.40, p < 0.001, and lower scores on the locus of control for moderation than did males, F(1, 317) = 5.56, p < 0.05. Females attributed moderation in food consumption more to external factors than did males. Because of the observed gender differences and the fact that females participated in the preloading phase of this study, the relations among the scales were separately examined for males and females. The correlations among the scales were carried out separately by gender and are shown in Tables 2 and 3. There were two focuses of these analyses: (a) the interrelations among the EASQ scales and (b) the relations between the EASQ scales and Restraint. 3.1.1. Interrelations among the EASQ scales There were significant correlations between indulgence and moderation incidents for each type of attributional style: (a) locus of control for indulgence was correlated with locus of control for moderation; (b) globality for indulgence was correlated with globality for Table 1 Means, standard deviations, and ranges of the scales by gender (and alphas) Females Scale

(Alphas)

Restraint Eating attributional style scales Moderation Locus of control (0.53) Globality (0.67) Stability (0.60) Importance (0.76) Indulgence Locus of control (0.60) Globality (0.68) Stability (0.59) Importance (0.77)

Males

Mean

SD

Range (min/max)

Mean

SD

Range (min/max)

13.39

6.46

1/33

9.91

5.45

0/35

16.05 12.39 14.67 8.90

3.29 3.74 3.03 3.73

5/20 4/20 4/20 4/20

16.91 12.24 14.71 8.54

2.77 4.01 2.86 4.03

9/20 4/20 8/20 4/19

16.67 11.16 14.22 9.36

3.22 3.66 3.21 4.03

5/20 3/20 2/20 1/20

17.21 10.50 14.51 8.66

3.10 3.96 2.82 3.81

8/20 4/20 8/20 2/20

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Table 2 Correlations among the measures for females (df = 205) Eating attributional style scales Moderation Measures

LCM

Restraint (Res)

ÿ 0.19**

Indulgence GM 0.25**

Eating attributional style scales Moderation Locus of ÿ 0.16* control (LCM) Globality (GM) Stability (SM) Importance (IM) Indulgence Locus of control (LCI) Globality (GI) Stability (SI) Importance (II)

SM 0.18**

ÿ 0.02 0.12

IM

LCI 0.40** ÿ 0.28**

ÿ 0.27**

0.30**

0.52** ÿ 0.10 0.26** 0.11 ÿ 0.15*

GI

SI

II

0.15*

ÿ 0.02

0.43**

0.16*

ÿ 0.02

ÿ 0.23**

0.62** 0.12 0.21** 0.43** 0.30* ÿ 0.06 ÿ 0.05

0.47** 0.22** 0.67**

0.37** ÿ 0.20** 0.23**

0.45** 0.02

* p < 0.05. ** p < 0.01.

moderation; (c) stability for indulgence was correlated with stability for moderation; and (d) importance for indulgence was correlated with importance for moderation. These correlations were the strongest in the data set and may be taken to suggest that there was an overall style of attribution across the two types of eating incidents. There were patterns of correlations among the scales within the moderation and indulgence incidents. For indulgence incidents, locus of control was positively correlated with stability and negatively correlated with importance. In addition, globality was positively correlated with stability and importance. These patterns were found across the two genders except that the correlation between locus of control and importance, although in the same direction, did not attain significance for males. For moderation incidents, the pattern of correlations differed for males and females. Locus of control was negatively correlated with globality and importance in females. For males, locus of control was positively correlated with stability, and globality was positively correlated with stability and importance. Despite the different patterns, there were no significant differences between the correlations for the two genders. In addition, there were various modest ``cross-over'' correlations among the scales that potentially occurred as an artifact of the aforementioned correlations among the attributional style scales. 3.1.2. EASQ and Restraint As shown in Tables 2 and 3, Restraint was significantly correlated with the perceived importance of the moderation and indulgent incidents depicted in the EASQ. This provides support for the validity of the scale by confirming the expectation that the

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Table 3 Correlations among the scales for males (df = 110) Eating attributional style scales Moderation Scales

LCM

Restraint (Res)

ÿ 0.03

Eating attributional style scales Moderation Locus of control (LCM) Globality (GM) Stability (SM) Importance (IM) Indulgence Locus of control (LCI) Globality (GI) Stability (SI) Importance (II)

Indulgence

GM

SM

0.23* 0.18

ÿ 0.08

IM

LCI 0.33** ÿ 0.20*

GI

SI 0.21*

II 0.07

0.38**

0.19* ÿ 0.05 0.21* ÿ 0.01 ÿ 0.21* ÿ 0.12 0.27** 0.56** ÿ 0.06 0.73** 0.14 0.36** 0.15 0.02 0.22* 0.35** 0.06 ÿ 0.09 0.36** 0.10 0.60** ÿ 0.03

0.18 ÿ 0.24* 0.32** 0.45** 0.15

* p < 0.05. ** p < 0.01.

indulgent and moderate food consumption would be more important for restrained than unrestrained eaters. For females, Restraint was negatively correlated with locus of control both for moderation and indulgence incidents. For males, Restraint was negatively correlated with locus of control for indulgence incidents only. For both genders, Restraint was positively correlated with: (a) globality for moderation and indulgence incidents and (b) stability for moderation incidents. Regression analyses were carried out for each gender in which the EASQ scales (excluding importance) were predictors, and Restraint was the dependent variable. For females, the regression analysis yielded a multiple R = 0.39, p < 0.001, in which the EASQ scales accounted for 16% of the variance of Restraint. The following scales accounted for unique portions of the Restraint variance: locus of control for indulgence incidents, b = ÿ 0.26, p < 0.001; stability for moderation incidents, b = 0.16, p < 0.05; and globality for moderation incidents, b = 0.17, p = 0.07. For males, the regression analysis yielded the multiple R = 0.33, p = 0.06, in which the EASQ scales accounted for 11% of the Restraint variance. Only the locus of control for indulgence incidents, b = ÿ 0.20, p < 0.05, was uniquely associated with Restraint. 3.1.3. Preloading effects The number of cookies eaten, including portions of the cookies eaten (calculated in quarters), served as the measure of the amount of food consumed. Preliminary analyses indicated that there was one clear outlier on the amount consumed (her food consumption differed from the sample, z = 5.21, p < 0.001) and, consequently, that individual's responses were dropped from the analyses. Outliers can distort findings and their removal has been strongly recommended (see Tabachnick & Fidell, 1996).

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A hierarchical regression analysis was carried out to assess the main effects of Restraint, Condition, and their interaction; the dependent variable was the amount consumed (see Aiken & West, 1991). The regression analysis yielded a main effect of Restraint, F(1, 96) = 7.33, p < 0.01, in which the amount consumed increased as a function of Restraint. The regression analysis did not yield a Restraint  Condition interaction, but specific predictions were examined regarding the relation between Restraint and amount consumed for the two conditions. These predictions were tested by a set of planned comparisons (O'Brian, 1983; Rutherford, in press). The observed relations are shown in Fig. 1. Consistent with the prediction, the amount consumed increased as a function of Restraint in the preload condition, b = 0.35, p < 0.05. The remaining findings conformed to prediction but did not attain conventional levels of significance: Individuals high in Restraint (restrained eaters) tended to consume more in preload than no-preload condition whereas individuals low in Restraint (unrestrained eaters) tended to consume less in the preload than no-preload condition. The lack of statistical significance was attributable to the tendency for the amount consumed to increase as a function of Restraint in the no-preload condition, as well as the preload condition. In order to examine the role that locus of control for indulgence played in food consumption, a similar hierarchical regression analysis was carried out. In this analysis, the effects of locus of control for indulgence, Condition, and the interaction between the attribution style and Condition were assessed. For the purpose of these analyses, the locus of control for indulgence was calculated such that greater numbers indicated greater externality. The regression analysis yielded a significant effect of External Locus of Control for Indulgence, F(1, 96) = 8.04, p < 0.01, that was qualified by an interaction between External Locus of Control for Indulgence and Condition, F(1, 96) = 5.92, p < 0.05. The interaction is plotted in Fig. 2. Analyses of the regression of the slopes (O'Connor, 1998) indicated that the

Fig. 1. Amount consumed as function of Restraint in preload and no-preload conditions.

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Fig. 2. The interaction between Condition and External Locus of Control for Indulgence on the amount consumed.

amount consumed increased as a function of External Locus of Control for Indulgence in the preload condition (b = 0.48, p < 0.01). High externals consumed more in the preload than the no-preload condition (scores > 13.75), whereas low externals consumed less in the preload than no-preload condition (scores < 2.86) as yielded by the Johnson±Neyman technique. 3.2. The mediational role of attribution styles Baron and Kenny (1986) proposed that evidence for a mediator is provided when the following three conditions are met: (a) there is a significant relation between the independent variable and the mediator; (b) there is a significant relation between the mediator and the dependent variable; and (c) the relation between the independent variable and the dependent is no longer significant when the mediator is included, with a zero relation serving as the strongest evidence for mediation. In the current study, it was only reasonable to examine the extent to which attribution style mediated the relation between Restraint (the independent variable) and amount consumed (the dependent variable) for the preload condition. Only in the preload condition was the independent and dependent variable significantly associated (b = 0.35, p < 0.05); a relation that conformed to expectation. The other relations for the preload condition were compatible with Baron and Kenny's (1986) requirements for mediation. There was an association between the hypothesized mediator (locus of control for indulgence) and the dependent variable (amount consumed), as previously reported (b = 0.48, p < 0.01). In addition, there was a relation between the independent variable (Restraint) and the moderator (External Locus of Control for Indulgence) (b = 0.24); this association attained significance for the complete sample, r(98) = 0.28, p < 0.01. When External Locus of Control for Indulgence was partialled out, the relation between Restraint and the amount consumed in

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the preload condition was no longer significant (b = 0.25) but of modest magnitude. These findings support the conclusion that the external locus of control mediated the relation between Restraint and amount consumed in the preload condition. Because the relation with the moderator controlled for was not of zero magnitude, though, the findings yield evidence only for partial mediation. 4. Discussion The current findings yielded support for the variability of external attribution style model of learned helplessness for dietary restraint. Restraint was associated with external locus of control attributions for both indulgent and moderation food consumption. Because locus of control attributions serves as an anchor for the other attribution dimensions, the findings also indicate that the external locus of control style comprises aspects of globality and stability. Restrained eaters believed that indulgence or moderate food consumption was due to external causes that were modestly consistent across situations and time, a relation shown particularly by females. The findings did not support the viability of the internal attribution model of learned helplessness for dietary restraint. Contrary to that model, dietary restraint was associated with external rather than internal locus of control attributions for indulgent food consumption. Because of those findings, it seems unlikely that the AVE is a cause of preloading effects. Some gender differences were found in the extent to which individuals demonstrated dietary restraint and the attribution styles. Greater dietary restraint and external locus of control for moderate food consumption scores were found for females than for males. Other researchers also have found greater scores on dietary restraint measures and dietary helplessness for females than for males (Carmody et al., 1995; see Herman & Polivy, 1980). The findings are consistent with the notion that, because females are more likely to engage in restrained eating than are males, females are more likely to experience the roller-coaster pattern of dieting success and failure and therefore establish a helplessness-oriented external locus of control attribution style for food consumption. Broadly, the current findings are consistent with the variety of studies suggesting that dietary restraint is associated with experiences of learned helplessness (Carmody et al., 1995; Green & Saenz, 1995; Troop & Treasure, 1997). The expected preloading effects were only partially observed in the current study. Consistent with expectation, food consumption increased as a function of restraint in the preload condition. In addition, restrained eaters tended to consume more food in the preload than no-preload conditions and unrestrained eaters tended to consume less food in the former than latter. These latter differences did not attain statistical significance, however. Such findings are consistent with previous studies that have failed to yield statistically significant increases in food consumption in restrained eaters as a result of preloading (i.e., Jansen, Merckelbach et al., 1988; Ruderman & Christensen, 1983; Wardle & Beales, 1987). The primary reason why the pattern did not attain significance resided in the tendency for the amount consumed to increase as a function of restraint in the no-preload condition. This tendency has been observed in some of the previous studies on preloading effects (e.g., Westenhoefer, Broeckmann, Munch, & Pudel, 1994) but appears to be contrary to the notion

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that restrained eaters generally inhibit their consumption of food. One account of the findings is that in the control, as well as the preloading, condition restrained eaters are deprived of food for a modest period and are tempted by desirable food. Those conditions alone may increase the likelihood that restrained eaters will violate their diets. Of considerable interest was the ``preloading'' effects with external locus of control as the variable. The amount of food consumed increased as a function of External Locus of Control for Indulgence in the preloading condition. In addition, individuals high in externality consumed more food in the preload than the no-preload condition, whereas individuals low in externality consumed less food in the former than the latter condition. Additionally, there was evidence to indicate that the locus of control for indulgent food consumption mediated, in part, the preloading effects for dietary restraint that were observed Ð the relation between dietary restraint and amount consumed in the preload condition. These findings are consistent with the external attribution helplessness model of preloading effects. Specifically, the findings support the hypotheses that: (a) preloading causes restrained eaters to perceive that they failed their diets thereby prompting cognitions comprising external attributions for eating, which in turn, cause them to relax their restraint and to increase their food consumption and (b) unrestrained eaters believe that eating is the result of internal causes and therefore decrease food consumption once they have become satiated by the preload. Why the complete pattern of preloading effects was found for external locus of control for indulgent food consumption but not for dietary restraint is an interesting question. One answer may be that external locus of control for indulgent food consumption has a more direct link to the preloading effects than does dietary restraint. As result, the preloading pattern is ``clearer'' for the former than the latter, although they are interdependent. In that same vein, the findings indicated that the external control attributions for indulgent food consumption attributions only served as a partial mediator. According to the external attribution model formulations, it is the external attributions arising from the preload for restrained eaters that account for the preloading effects. The EASQ scales assess individuals' styles of attribution that only modestly predict the attributions they make in any given situation. Therefore, stronger evidence for external attributions as a mediator of the relation between dietary restraint and food consumption as a result of a preload should be found when individuals' attributions during or immediately after a preload are assessed. These hypotheses warrant further investigation. The findings yielded by the current study supported the hypotheses that: Restrained eaters display an external attribution style of learned helplessness and external attribution cognitions contribute to preloading effects. In the future, researchers should examine the specific manner in which external attributions contribute to preloading effects. For example, during preloading, restrained eaters should be more inclined to generate external attributions regarding food consumption than would unrestrained eaters. Also, therapeutic implications of the findings should be examined. Interventions could be implemented to increase internal attribution styles in restrained eaters (and others with related eating disorders) in order to reduce their learned helplessness. When developing these interventions, it is important to consider the distinction between behavioral self-blame (controllable, unstable, self-attributions) and characterological self-blame (uncontrollable, stable self-attributions); the latter but not the former is linked to depression (Anderson, Miller, Rigeer, Dill, & Sedikides, 1994). A

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