Evaluating the Power of Food Scale in obese subjects and a general sample of individuals: development and measurement properties.

BACKGROUND: The Power of Food Scale (PFS) was developed to assess the psychological impact of today's food-abundant environments. OBJECTIVE: To evaluate the structure of the PFS in diverse populations of obese and nonobese individuals. DESIGN: Data were obtained from obese adults in a clinical trial for a weight management drug (n=1741), and overweight, obese and normal weight adults in a Web-based survey (n=1275). Exploratory and confirmatory factor analyses were used to investigate the PFS structure using the clinical data. The model developed was then tested using the Web-based data. Relationships between PFS domains and body mass index (BMI) were examined. Logistic regression was used in the Web-based survey to evaluate the association between obesity status and PFS scores. RESULTS: Clinical data indicated that the scale was best represented by a 15-item version with three subscale domains and an aggregate domain (average of three domains); this was confirmed with data from the Web-based survey (Comparative Fit Index: 0.95 and 0.94 for the clinical and Web-based studies, respectively). Cronbach's alpha for both data sets was high, ranging from 0.81 to 0.91. The relationships between BMI and each domain were weak (and approximately linear). A full category increase in PFS domain score (range 1-5) increased the odds of being obese 1.6-2.3 times. CONCLUSIONS: The 15-item PFS is best represented by three domains and an aggregate domain. The PFS may provide a useful tool to evaluate the effects of obesity treatments on feelings of being controlled by food in an obesogenic food environment.

Psychometric analysis of the Three-Factor Eating Questionnaire-R21: results from a large diverse sample of obese and non-obese participants.

BACKGROUND: The 21-item Three-Factor Eating Questionnaire (TFEQ-R21) is a scale that measures three domains of eating behavior: cognitive restraint (CR), uncontrolled eating (UE) and emotional eating (EE). OBJECTIVES: To assess the factor structure and reliability of TFEQ-R21 (and if necessary, refine the structure) in diverse populations of obese and non-obese individuals. DESIGN: Data were obtained from obese adults in a United States/Canadian clinical trial (n=1741), and overweight, obese and normal weight adults in a US web-based survey (n=1275). Confirmatory factor analyses were employed to investigate the structure of TFEQ-R21 using baseline data from the clinical trial. The model was refined to obtain adequate fit and internal consistency. The refined model was then tested using the web-based data. Relationships between TFEQ domains and body mass index (BMI) were examined in both populations. RESULTS: Clinical data indicated that TFEQ-R21 needed refinement. Three items were removed from the CR domain, producing the revised version TFEQ-R18V2 (Comparative Fit Index (CFI)=0.91). Testing TFEQ-R18V2 in the web-based sample supported the revised structure (CFI=0.96; Cronbach's coefficient alpha of 0.78-0.94). Associations with BMI were small. In the clinical study, the CR domain showed a significant and negative association with BMI. On the basis of the web-based survey, it was shown that the relationship between BMI and CR is population-dependent (obese versus non-obese, healthy versus diabetics). CONCLUSIONS: In two independent datasets, the TFEQ-R18V2 showed robust factor structure and good reliability. It may provide a useful tool for characterizing UE, CR and EE.

Self-reported history of overweight and its relationship to disordered eating in adolescent girls with Type 1 diabetes.

AIMS: Increased body weight and disordered eating attitudes/behaviours are common in adolescent girls with Type 1 diabetes (T1D). Disordered eating increases risks for diabetes-related complications. This study aimed to identify a rapid screening approach for disordered eating attitudes and behaviours in adolescent girls with T1D and to examine the relationship between disordered eating and body weight in this population. METHODS: Ninety adolescent girls, aged 12-19 years, provided a self-assessment of weight status. Participants also completed questionnaires to assess attitudes/behaviours toward food and eating, appetitive responsiveness to the food environment, disinhibition in eating and weight history. RESULTS: Forty-three per cent of participants reported a history of overweight. Compared with participants who reported never being overweight, those who reported ever being overweight were significantly older, scored significantly higher on all measures of disordered eating attitudes/behaviours (P < or = 0.009) and were 4.8 times more likely to be currently overweight or obese (P < 0.001). Glycated haemoglobin (HbA(1c)) was similar between those who did and did not report ever being overweight. CONCLUSIONS: Because of the ill-health effects of disordered eating and the higher rate of overweight in adolescent girls with T1D, effective screening tools are warranted. The single question 'Have you ever been overweight?' may be sufficient as a first question to screen for those at high risk for disordered eating attitudes/behaviours and to provide early intervention and prevention.

A narrative review of the construct of hedonic hunger and its measurement by the Power of Food Scale.

INTRODUCTION: The term 'hedonic hunger' refers to one's preoccupation with and desire to consume foods for the purposes of pleasure and in the absence of physical hunger. The Power of Food Scale (PFS) was developed as a quantitative measure of this construct in 2009. Since then, over 50 published studies have used the PFS to predict appetite-related outcomes including neural, cognitive, behavioural, anthropometric and clinical measures. OBJECTIVE: This narrative review evaluates how closely the PFS captures the construct it was originally presumed to assess and to more clearly define hedonic hunger itself. METHODS: The measure's relationship to four domains is reviewed and summarized: motivation to consume palatable foods; level of actual consumption of such foods; body mass; and subjective loss-of-control over one's eating behaviour. Findings are synthesized to generate a more accurate understanding of what the PFS measures and how it may relate to the broader definition of hedonic hunger. RESULTS: Results suggest that the PFS is closely related to motivation to consume palatable foods and, in extreme cases, occurrence of loss-of-control eating episodes. PFS scores are not consistently predictive of amount of food consumed or body mass. CONCLUSIONS: Implications of these findings are discussed in the context of behavioural health, and avenues for further inquiry are identified.

The relation of hedonic hunger and restrained eating to lateralized frontal activation.

Asymmetrical alpha activation in the prefrontal cortex (frontal asymmetry) in electroencephalography (EEG) has been related to eating behavior. Prior studies linked dietary restraint with right frontal asymmetry [1] and disinhibition with left frontal asymmetry [2]. The current study simultaneously assessed restrained eating and hedonic hunger (drive for food reward in the absence of hunger) in relation to frontal asymmetry. Resting-state EEG and measures of restrained eating (Revised Restraint Scale; RRS) and hedonic hunger (Power of Food Scale; PFS) were assessed in 61 non-obese adults. Individually, hedonic hunger predicted left asymmetry. However, PFS and RRS were correlated (r=0.48, p<0.05) and there was a significant interaction between PFS and RRS on frontal asymmetry, p<0.01. Results indicated that those high in hedonic hunger exhibited left asymmetry irrespective of RRS scores; among those low in PFS, only those high in RRS showed right asymmetry. Results were consistent with literature linking avoidant behaviors (restraint) with right-frontal asymmetry and approach behaviors (binge eating) with left-frontal asymmetry. It appears that a strong drive toward palatable foods predominates at a neural level even when restraint is high. Findings suggest that lateralized frontal activity is an indicator of motivation both to consume and to avoid consuming highly palatable foods.

Dieting: proxy or cause of future weight gain?

The relationship between dieting and body mass has a long and controversial history. This paper aims to help resolve this issue by making two key distinctions. The first is between dieting as a cause of weight gain/regain and as a proxy risk factor for identifying non-obese individuals prone to weight gain for reasons other than dieting. The second is between the body mass that is attained following one or more weight loss/regain cycles and the body mass that might have been reached had dieting never been undertaken. Evidence is reviewed on the relation between recent diet-induced weight loss and sustained weight loss (weight suppression), on the one hand, and weight regain, on the other hand. Furthermore, the reason that a history of dieting in non-obese individuals reflects a susceptibility to future weight gain is explained. It is concluded that (i) diet-induced weight loss hastens weight regain but a history of weight loss diets does not cause weight gain beyond that which would occur in the absence of dieting, and (ii) weight loss dieting in non-obese individuals does not cause future weight gain but is simply a proxy risk factor reflecting a personal vulnerability to weight gain and living in an obesogenic environment.

Personal history of dieting and family history of obesity are unrelated: implications for understanding weight gain proneness.

Identifying predictors of future weight gain is important in obesity prevention efforts. Both family history of obesity and personal dieting history have been established as predictors of future weight gain; however, it is unknown if they are independent or overlapping predictors. The purpose of this study was to examine the degree of overlap between these two predictors using cross-sectional data. Baseline data from four studies were examined separately and in combination for a total of 561 female participants, and analyses were conducted to examine parent anthropometric variables by dieting status within and across studies. All participants were female university students between the ages of 17 and 30. For each study, as well as for the entire sample combined, parent anthropometric variables were examined by dieting status using factorial ANOVAs. No meaningful pattern was found when examining parent anthropometric variables by dieting status, which suggests that the two risk factors are largely independent. This suggests that the processes associated with the development of future weight gain by each variable are different; therefore, future research should use a longitudinal study to test the hypothesis that using both variables to predict future weight gain would account for more variance than using either variable alone.

Seizures, lateral decubitus, aspiration, and shoulder dislocation: Time to change the guidelines?

The recommendation to position a patient having a seizure on a lateral decubitus is aimed at minimizing the risk of aspiration. The authors reviewed the database of the Epilepsy Foundation Clinic of South Florida for patients with epilepsy treated for pneumonia between May 1999 and May 2000 and patients admitted to two university telemetry units who had dislocation of the shoulder during an epileptic seizure. Over 2 months, 2 of 733 adults with intractable seizures had aspiration pneumonia after a generalized tonic clonic seizure (GTCS). Although no study has specifically addressed the problem of aspiration pneumonia in adults with GTCS, our findings suggest this problem is not common. From the two epilepsy centers, 5 of 806 patients dislocated a shoulder during a seizure. Video recordings showed that these patients were positioned in a lateral decubitus by staff while still having the convulsion. The dislocated shoulder in all cases was on the lower side. The risk of shoulder dislocation in a convulsing patient positioned in a lateral decubitus is less than 1%. Nevertheless, dislocations can result in disabling recurrences and are easily preventable. Because aspiration is more likely in the postictal rather than ictal phase of a GTCS, when oral secretions are not usually increased and there is cessation of respiratory movements, lateral decubitus should only be implemented after cessation of the convulsion, In inpatients (such as those on telemetry), secretions may be better managed by bedside aspiration of the oral cavity.

Nonepileptic seizures in pregnancy.

The authors report five patients with recurrent psychogenic seizures (PS) during pregnancy, with multiple emergency room visits and continued intake of antiepileptic drugs obtained from various sources, despite awareness of the psychogenic nature of their attacks and the risks of antiepileptic drug use in pregnancy. These patients demonstrate that preexisting PS may persist during pregnancy, and there will be patients who continue to take antiepileptic drugs despite awareness of the risks inherent to these treatments. New-onset or persisting PS with pregnancy can be indicative of serious emotional conflicts, and the child should be considered at risk.

The effects of dieting on eating behavior: a three-factor model.

I review and critique restraint theory and develop a 3-factor model of dieting behavior. The factors--frequency of dieting and overeating, current dieting, and weight suppression--are embedded within a 3-dimensional grid that also considers mechanisms mediating the effects of dieting and the influence of weight status. I argue that the eating behavior exhibited by restrained eaters stems from their frequent dieting and overeating in the past rather than from their current state of dietary or cognitive restraint. Evidence is reviewed, indicating that current dieting and weight suppression have different effects on eating than does restraint. The 3-factor model is used to reinterpret findings consistent with restraint theory and to explain findings inconsistent with restraint theory. Finally, clinical and research implications of the 3-factor model are discussed.

On the relation of dieting and bingeing in bulimia nervosa.

The continuum model of bulimia nervosa suggests that dieting plays a major role in the etiology and maintenance of bulimia. However, a previous study (M. R. Lowe et al., 1996) recently found no relationship between dieting intensity and binge eating problems in nonclinical participants differing widely in eating and weight concerns. The present study extended these findings by examining the relationship between dieting and bingeing among individuals with bulimia. Three samples of individuals diagnosed with bulimia were divided into frequent and infrequent weight-loss dieters and were compared on multiple measures of binge eating. No diet-binge relationship was found in 1 sample, whereas in the other 2 samples frequent dieters binged less than infrequent dieters. These results raise new questions about the continuum model of bulimia and suggest that weight-loss dieting may not play as prominent a role in the maintenance of bulimia as it does in its initiation.

Continuity and discontinuity models of bulimia nervosa: a taxometric investigation.

Past research evaluating the continuity and discontinuity models of bulimia has produced inconclusive results. In the current study, we performed a taxometric analysis of bulimia nervosa using means above minus below a sliding cut and maximum covariance analysis with a sample of women diagnosed with bulimia nervosa (n = 201) or women college students (n = 412). Indicators were derived from the Bulimia Test--Revised and the Eating Attitudes Test--26, and both a mixed sample and the nonclinical sample were analyzed. With both taxometric methods and both mixed and nonclinical samples, results were consistently suggestive of a latent taxon for bulimia. These results challenge a dimensional model of bulimia nervosa.

Restraint, dieting, and the continuum model of bulimia nervosa.

The authors evaluated the continuity model of bulimia nervosa, which suggests that bulimia results from extreme weight concern and dieting practices. Individuals with bulimia, current dieters, restrained nondieters, and unrestrained nondieters were compared on measures of general psychopathology, eating-disorder-specific psychopathology, and overeating. Multiple methods, including questionnaires, clinical interviews, and food records, were used to collect data. The continuity and discontinuity models were tested with trend and regression analyses. The results of most analyses were consistent with the continuity perspective. However, binge eating behaviour exhibited a clear nonlinear trend, which occurred because binge eating was common in bulimic individuals but virtually non-existent in the other 3 groups. Current dieters scored higher than restrained nondieters on restraint/ weight concern, but not on psychopathology or binge eating. Overall, the results suggest that "normal" dieting is associated with psychological, but not consummatory, symptoms of bulimia.

Weight loss and sweetness preferences: the effects of recent versus past weight loss.

The present study examined the effects of weight loss, recent and past, on perceptions of pleasantness and sweetness intensity of sucrose solutions. Subjects high or low in current weight loss, and high or low in past weight loss (weight suppression) rated sucrose solutions before and after the ingestion of a glucose solution. Current weight loss was total weight loss over the 3 months prior to the study; past weight loss was defined in terms of the difference between maximal and current weight. Subjects were 40 women, all of whom reported that they were dieting. After a 12-hour overnight fast, each subject tasted and rated five concentrations of sucrose solutions (2.5, 5.0, 10.0, 20.0, and 40.0) for pleasantness and sweetness. High weight suppressors rated the sucrose solutions, before and after the glucose load, as significantly less pleasant than did low weight suppressors. High recent weight losers rated the sucrose solutions as significantly more pleasant than did low current weight losers following, but not prior to, the glucose load. These results were inconsistent with setpoint theory. High weight suppressors did not show an increase in sweetness preference as predicted by this theory. It was suggested that while weight loss affects taste hedonics, the nature of this relationship depends on the recency of the weight loss.

Depot neuroleptics and manic depressive psychosis.

Twelve patients (eight men and four women) suffering from manic depressive disorder who were receiving both lithium and antipsychotic medication had their antipsychotic changed to depot haloperidol decanoate, with their lithium medication remaining unchanged. Successful transfer to haloperidol decanoate was achieved with a reduced incidence of extrapyramidal side effects, and 100% compliance in eight patients who all remained free of hypomanic relapse, including four patients with rapid-cycling disorder. By comparison, in the three years before switching to haloperidol decanoate these four patients had required sixteen admissions for hypomanic relapses resulting in thirty-four months in-patient treatment.

Persisting aphasia as the sole manifestation of partial status epilepticus.

OBJECTIVES: Persisting aphasia presenting as an isolated inability to vocalize is an uncommon presentation of simple partial status epilepticus and only eight such cases have been reported over the past 40 years. METHODS: We studied a patient with a 5-year history of recurrent episodes of inability to talk, without any other motor or cognitive impairments. Episodes lasted as long as 24 h, interictal EEGs were normal and she was diagnosed as a conversion disorder. RESULTS: EEG recordings during one of the episodes showed continuous discharges in the right frontal and parasagital areas demonstrating the ictal nature of the deficits. During the episode the patient had no deficits of strength, or in her ability to perform skilled movements to command, imitation or manipulation of objects. Comprehension of complex verbal commands was preserved and she would make attempts to articulate words and correctly answered questions with head nodding or monosyllables, yes or no. She could hum but had no other vocalizations. CONCLUSIONS: This is the first case of aphasic status epilepticus secondary to epileptogenic discharges of the right hemisphere. The case is also unique for the isolated involvement of production of language during the seizure.

Regulation of squalene epoxidase activity by membrane fatty acid composition in yeast.

Depriving Saccharomyces cerevisiae strain GL7 of exogenous unsaturated fatty acid supplements causes this sterol biosynthetic mutant to accumulate squalene at the expense of squalene epoxide and squalene diepoxide. To further characterize the apparent relationship between squalene epoxidase activity and membrane fatty acid composition, a variety of unsaturated fatty acids differing in their chain lengths and in the positions and orientation (cis or trans) of their double bonds were tested for their ability to promote turnover of endogenous squalene in cells previously deprived of olefinic supplements. All of the unsaturated fatty acids tested were found to restore squalene epoxidase activity but there were marked differences in their efficacies that best were correlated with the extent to which they reduced the medium chain (C-10 + C-12) saturated fatty acid content of cellular phospholipids. Additional studies demonstrated that de novo protein synthesis was required for the restoration of squalene epoxidase activity in unsaturated fatty acid-deprived cells.

Putting restrained and unrestrained nondieters on short-term diets: effects on eating.

This study examined the joint effect of restrained eating status and short-term food restriction on ice cream consumption in the laboratory. Restrained and unrestrained eaters who were not dieting were asked to restrict their food intake for 2 days or to continue eating normally. They then engaged in an ostensible taste test of ice cream. A restraint x restriction interaction was found for ice cream consumption. Among unrestrained eaters, restricted subjects ate more than unrestricted ones; among restrained eaters, the opposite eating pattern was found. These results were attributed to the differential sensitivity of restrained and unrestrained eaters to the internal and external eating cues manipulated in the study.

Restraint, disinhibition, hunger and negative affect eating.

The Three-Factor Eating Questionnaire (Stunkard & Messick, 1985) contains factors measuring dietary restraint, disinhibition, and hunger. In this study, the ability of these factors to predict eating responses to negative affect was tested. The Velten mood induction procedure was used to produce neutral or depressed moods in normal weight college students. Subjects were encouraged to sample candy which was made available during the mood induction procedure. The results indicated that the Hunger factor was the only significant predictor of negative affect eating. Depressed, high-hunger subjects were more likely to eat than subjects in other conditions and, in on of two analyses of amount of candy consumed, were found to eat the most candy as well. The possibility that these results could be explained by an overlap between the Hunger factor and the construct of external responsiveness was considered. Implications of the overall findings for theories of emotional eating were briefly discussed.

Restrictive dieting vs. "undieting" effects on eating regulation in obese clinic attenders.

This study tested predictions from restraint theory [Herman & Polivy (1984). A boundary model for the regulation of eating. In: A. J. Stunkard, & E. Stellar (Eds.), Eating and its disorders (pp. 141-156) New York: Raven Press.] and the three-factor model of dieting [Psychol. Bull. 114 (1993) 100.] using an eating regulation paradigm. Participants were 42 obese, nonbinge eaters assigned to either a weight loss group (restrictive dieters or RDs) or a group designed to eliminate dieting ("undieters" or UDs). Participants took part in an ostensible ice cream taste test with or without a preload, both before and after the weight control intervention. At pretest, restraint theory's prediction that participants would engage in counter-regulatory eating was not supported. At posttest, after 8 weeks of the dieting interventions, RDs increased and UDs decreased their intake following a preload, a pattern most consistent with the predictions of restraint theory. This counter-regulatory trend was observed in spite of a significant decrease in RDs' Disinhibition scale scores following treatment. Implications of these findings for restraint theory, the three-factor model of dieting, and relapse in obesity treatment were discussed.