An experimental test of the effect of weight-loss dieting on bulimic pathology: tipping the scales in a different direction

Although it is widely accepted that dieting increases the risk for bulimic pathology, this hypothesis has not been tested in a randomized experiment. Accordingly, the authors conducted an experimental test of the dietary restraint model by randomly assigning nonobese women (N = 82) to either a 6-week, low-calorie diet or a waitlist control condition. The diet intervention resulted in significant weight loss, confirming that dieting was successfully manipulated. Contrary to the restraint model, dieting resulted in significant decreases in bulimic symptoms relative to the control condition. Results converge with past findings from randomized obesity prevention and treatment trials and provide evidence that dieting does not promote bulimic pathology; rather, effective decreases in caloric intake appear to reduce bulimic symptoms.     

A prospective test of the dual-pathway model of bulimic pathology: mediating effects of dieting and negative affect

Because there have been few longitudinal investigations of integrative etiological theories of bulimia nervosa, this study prospectively tested the dual-pathway model using random regression growth curve models and data from a 3-wave community sample of adolescent girls (N = 231). Initial pressure to be thin and thin-ideal internalization predicted subsequent growth in body dissatisfaction, initial body dissatisfaction predicted growth in dieting and negative affect, and initial dieting and negative affect predicted growth in bulimic symptoms. There was prospective evidence for most of the hypothesized mediational effects. Results are consistent with the assertion that pressure to be thin, thin-ideal internalization, body dissatisfaction, dieting, and negative affect are risk factors for bulimic pathology and provide support for the dual-pathway model.     

Eating regulation and bulimic symptoms: the differential correlates of health-focused and appearance-focused eating regulation

Based on Self-Determination Theory, this study aimed to gain further insight in the pathway from eating regulation to bulimic symptoms by (a) examining diet-specific need frustration as an intervening mechanism, (b) investigating the associations between different types of goals underlying eating regulation and diet-specific need frustration and bulimic symptoms, and (c) considering body dissatisfaction as an antecedent of eating regulation and eating regulation goals. In a sample of 244 female adolescents, SEM analyses showed that (a) the association between eating regulation and bulimic symptoms can be accounted for by need frustration, (b) appearance-focused and health-focused eating regulation are associated differentially with need frustration and bulimic symptoms, and (c) body dissatisfaction is related positively to eating regulation and appearance-focused eating regulation. These findings suggest that the goals underlying one's eating regulation and the concept of need frustration help to understand when and why eating regulation is associated with bulimic symptoms.     

Objective and subjective bulimic episodes in the classification of bulimic-type eating disorders: Another nail in the coffin of a problematic distinction

We sought to further explore the validity of the distinction between objective bulimic episodes (OBEs) and subjective bulimic episodes (SBEs) in the study of bulimic-type eating disorders. Drawing on data obtained at the second, interview phase of a large-scale epidemiological study, we identified mutually exclusive subgroups of women with bulimic-type eating disorders who engaged in regular OBEs but not SBEs (n = 37) or regular SBEs but not OBEs (n = 52). These subgroups were compared on a wide range of outcomes, including socio-demographic characteristics, current levels of eating disorder psychopathology, general psychological distress and impairment in role functioning, current and lifetime impairment in quality of life specifically associated with an eating problem, (self)-recognition of an eating problem, health service utilization and use of psychotropic medication. The only difference between groups was that participants who reported regular OBEs were heavier than those who reported regular SBEs. The findings converge with those of previous research in suggesting that bulimic-type eating disorders characterized by regular SBEs, but not OBEs, do not differ in any clinically meaningful way from those characterized by regular OBEs, but not SBEs. Inclusion of bulimic-type eating disorders characterized by regular SBEs as a provisional category requiring further research in DSM-V appears warranted.     

The impact of exposure to images of ideally thin models in TV commercials on eating behavior: an experimental study with women diagnosed with bulimia nervosa

This study investigates whether eating behavior in women with diagnosed bulimia nervosa is influenced by prior exposure to images of ideally thin models. Twenty-six participants diagnosed with bulimia nervosa (BN) and 30 normal controls (NC) were exposed to body-related and neutral TV commercials; then food that typically triggers binge eating was provided, and the amount of food eaten was measured. No significant difference for food intake between NC and BN could be found, but food intake for BN was predicted by the degree of thoughts related to eating behaviors during exposure to the thin ideal. No impact of general body image or eating pathology on food intake could be found. The results emphasize the importance of action-relevance of dysfunctional cognitions for the maintenance of eating-disordered behaviors in women with bulimia nervosa, when exposed to eating-disorder-specific triggers.     

Changing the body image concern and eating behaviour of chronic dieters: The effects of a psychoeducational intervention

Abstract

A program designed to diminish body image concern and to normalise the eating of chronic dieters was evaluated experimentally and by monitoring outcomes for 12 months. The subjects were 82 females (mean age 44.4 years, mean BMI 31.4). Data from repeated measures of eating style, self-esteem and body shape concern revealed a strong, positive and enduring intervention effect. At 12 months the majority (86%) of the subjects were not dieting and 73% reported “sometimes” or “often” engaging in natural eating, i.e., unrestrained and physiologically cued eating. A positive relationship was found between extent of natural eating and the likelihood of weight loss or weight maintenance. It is concluded that female dieters can derive considerable benefits from programs promoting natural eating.     

Effects of a weight maintenance diet on bulimic symptoms in adolescent girls: an experimental test of the dietary restraint theory.

It is widely accepted that dieting increases the risk for bulimia nervosa, but there have been few experimental tests of this theory. The authors conducted a randomized experiment with adolescent girls (N=188) to examine the effects of a weight maintenance diet on bulimic symptoms. A manipulation check verified that the diet intervention resulted in weight maintenance and significantly reduced the risk for obesity onset and weight gain observed in assessment-only controls. As hypothesized, the diet intervention resulted in significantly greater decreases in bulimic symptoms and negative affect than observed in controls. These experimental findings, which converge with those from a weight loss diet experiment, appear antithetical to dietary restraint theory and suggest instead that dietary restriction curbs bulimic symptoms.     

Why dieters fail: Testing the goal conflict model of eating

A new theory of eating regulation is presented to account for the over-responsiveness of restrained eaters to external food-relevant cues. According to this theory, the food intake of restrained eaters is characterized by a conflict between two chronically accessible incentives or goals: eating enjoyment and weight control. Their difficulty in weight control is due to their behavioral sensitivity to eating enjoyment and its incompatibility with the eating control goal. Accordingly, exposure to food-relevant stimuli primes the goal of eating enjoyment in restrained (but not unrestrained) eaters, resulting in an inhibition of weight control thoughts. Three studies are reported that support these assumptions. Study 1 demonstrates a substantial relation between Eating Restraint and measures of ambivalence towards eating. Studies 2 and 3 show that priming eating enjoyment decreases the accessibility of eating control concepts. The results are discussed in the context of current research on the psychology of obesity and restrained eating.     

An experimental manipulation of metacognition: A test of the metacognitive model of obsessive-compulsive symptoms

The metacognitive model of obsessive-compulsive symptoms [Wells, A. (1997). Cognitive therapy of anxiety disorders: A practice manual and conceptual guide. Chichester, UK: Wiley] assigns a necessary causal role to metacognitive beliefs in the development of symptoms. The current study tested the model by evaluating the effects of experimentally manipulating such beliefs. A 2 × 2 factorial design was used. Thirty-two students with high and 32 students with low obsessional symptoms were subject to an experimental (metacognitive belief induction) or control (no metacognitive belief induction) condition. All participants underwent fake EEG recordings and were informed that the EEG could sense hypothalamus activity caused by having thoughts related to drinking. Participants in the experimental condition were told that if such thoughts were detected they may be exposed to an aversive noise. Controls were told that they may hear an aversive noise but this would be unrelated to the thoughts they had. Results showed a significant interaction effect between level of obsessional symptoms and belief induction. Analysis of this effect demonstrated that in the high obsession group, participants in the experimental condition had significantly more intrusions about drinking, time spent thinking about these intrusions and discomfort from them, than controls. There were also significant main effects on some measures, such as effort to control intrusions about drinking, with higher scores in the experimental condition irrespective of levels of obsessional symptoms. Results support the metacognitive model.     

An experimental test of the effects of gender constancy on sex typing

This study provides an experimental test of the hypothesis that level of gender constancy understanding affects children’s sex typing. Preschool-age children (N = 62, mean age = 47 months) were randomly assigned to experimental lessons that taught that biological traits (including gender) are either fixed (pro-constancy condition) or mutable (anti-constancy condition). Posttests revealed that the lessons were effective; children in the pro-constancy condition showed higher gender constancy and appearance–reality distinction scores than did children in the anti-constancy condition. Sex typing did not, however, differ between treatment conditions at immediate and 3-month posttesting.     

Word frequency and root-morpheme frequency effects on processing of Korean particle-suffixed words

Two experiments investigated the roles of the frequency of the root morpheme and the frequency of the whole word for a particular type of suffixed word in Korean in which the suffixed word can be thought of as a phrase (e.g., grandson-with). In both experiments, sentence frames were constructed so that they could have one of two target words that varied on frequency characteristics in the same location in the sentence. In Experiment 1, the frequency of the root morpheme was varied with the frequency of the word controlled, and in Experiment 2, the frequency of the word was varied with the frequency of the root morpheme controlled. Word frequency had a significant effect on fixation times, whereas root morpheme frequency did not. The results were surprising as native Korean speakers view the root morpheme as the “word” (analogous to how English readers would view a noun followed by a prepositional phrase).     

The moderating effect of avoidant coping on restrained eaters' risk for disinhibited eating: implications for dietary relapse prevention

Avoidant coping style was tested as a moderating variable for the effect of ego threat on chronic dieters' (restrained eaters) risk for disinhibited eating. Young women (n=146) were randomly assigned to a speech threat or to a no threat condition and then participated in a bogus ice cream taste test. Analyses of covariance revealed that restrained eaters who scored higher on a standardized measure of avoidant coping consumed significantly more ice cream than restrained eaters who scored lower on avoidant coping regardless of the threat condition to which they were assigned. The findings suggest that dieters prone to using avoidant coping strategies may be particularly vulnerable to overeating and, therefore, could be at risk for lapses in dietary restraint. Hence, dietary relapse prevention programs might target dieters who tend to use avoidant coping strategies for cognitive-behavioral therapy to teach them adaptive coping skills.     

The impact of feedback frequency on learning and task performance: Challenging the “more is better” assumption

Previous research on feedback frequency suggests that more frequent feedback improves learning and task performance (Salmoni, Schmidt, & Walter, 1984). Drawing from resource allocation theory (Kanfer & Ackerman, 1989), we challenge the “more is better” assumption and propose that frequent feedback can overwhelm an individual’s cognitive resource capacity, thus reducing task effort and producing an inverted-U relationship with learning and performance over time. We then propose that positive and negative affective states will moderate the inverted-U relationship between feedback frequency and task performance. We test these propositions in an experimental study where the frequency of task feedback is manipulated. Results show that feedback frequency exhibits an inverted-U relationship with task performance, and this relationship is mediated by task effort. This curvilinear relationship is then moderated by individual’s positive affective state.     

An experimental study of the effects on item-analysis data of changing item placement and test time limit

Item-analysis data are usually obtained from a single test administration, with a given item sequence and time limit. Questions can be raised as to the effects upon item data resulting from changes in item-position and test-timing. In this study, two forms of a verbal test and two forms of a mathematics test were used. In each case, both forms of each test contained the same items, but items coming early in one form were placed late in the other. Each of these forms was administered once with a short time limit and once with generous timing to comparable groups of high school students. The relationships of various speed and power scores were determined, and the changes which occurred during the added time were studied. Values of the item indicesp (proportion right), (another difficulty index), and the item-test biserial correlation coefficient were obtained for both the speed and the power conditions and were systematically compared. The proportion right of those attempting the item, the index, and the biserialr were all found to have undesirable characteristics for items appearing late in a speeded test.The author gratefully acknowledges the suggestions and criticisms of Dr. Harold Gulliksen, Research Adviser at the Educational Testing Service.     

Who when where: An experimental test of the event-indexing model

We tested the event-indexing model proposed by Zwaan, Langston, and Graesser (1995). Participants read narratives containing target sentences that involved situational shifts. Independently of each other, continuity and shifting of the protagonist, time, and location dimensions were varied. In Experiment 1, reading times of the target sentences increased for protagonist shifts and temporal shifts, whereas the effect of spatial shifts was weak. Moreover, an interaction of protagonist shifts and spatial shifts was found. These results were replicated in Experiment 2, which also revealed strong effects of these situational shifts on coherence ratings that participants gave immediately after reading each target sentence. Experiment 3 addressed the interaction of protagonist shifts and spatial shifts, showing that it may be due to the differential involvement of unexplained protagonist motions. These experimental results support the processing load predictions of the event-indexing model and extend previous correlational results.     

Disentangling the effects of word frequency and contextual diversity on serial recall performance

Research shows that contextual diversity (CD; the number of different contexts in which a word appears within a corpus) constitutes a better predictor of reading performance than word frequency (WF), that it mediates the access to lexical representations, and that controlling for contextual CD abolishes the effect of WF in lexical decision tasks. Despite the theoretical relevance of these findings for the study of serial memory, it is not known how CD might affect serial recall performance. We report the first independent manipulation of CD and WF in a serial recall task. Experiment 1 revealed better performance for low CD and for high WF words independently. Both effects affected omissions and item errors, but contrary to past research, word frequency also affected order errors. These results were confirmed in two more experiments comparing pure and alternating lists of low and high CD (Experiment 2) or WF (Experiment 3). The effect of CD was immune to this manipulation, while that of WF was abolished in alternating lists. Altogether the findings suggest a more difficult episodic retrieval of item information for words of high CD, and a role for both item and order information in the WF effect.     

Effects of achievement goals on self-regulation of eating attitudes among elite female athletes: An experimental study

Introduction

The influence of achievement goals on eating attitudes has mainly been examined through correlational studies (e.g., [De Bruin et?al., 2009] and [Duda and Kim, 1997]), and none of the studies to date has focused on the self-regulation of eating attitudes in athletes. The present study experimentally tested the effects of achievement goals on both self-reported (Study 1) and behavioral indices (Study 2) of the self-regulation of eating attitudes in female figure skaters.

Method

Elite female figure skaters (Study 1: n = 44; Study 2: n = 54) were randomly assigned to one of four conditions designed to induce specific goal involvement (performance-approach, mastery-approach, performance-avoidance, and mastery-avoidance) or a control condition (no goal induction). The participants in Study 1 completed the Self-Regulation of Eating Attitudes in Sport Scale (SREASS, Scoffier, Corrion, Paquet, & Arripe-Longueville, 2010) and those in Study 2 completed a virtual behavioral measure of self-regulation of eating attitudes (VSSR; Scoffier, 2009).

Results

Variance analyses indicated that induced mastery-approach goals and performance-avoidance goals resulted in higher scores for self-regulation of eating attitudes than induced performance-approach goals and mastery-avoidance goals. The relationships were the same at both self-reported and behavioral levels.

Discussion

This experimental study confirms the findings of previous correlational works and shows that achievement goals contribute to the causal processes of self-regulation of eating attitudes. These findings might help to prevent eating disorders in female athletes by providing guidance for the development of adapted motivational strategies.