Selective Visual Attention during Mirror Exposure in Anorexia and Bulimia Nervosa

Objective

Cognitive theories suggest that body dissatisfaction results from the activation of maladaptive appearance schemata, which guide mental processes such as selective attention to shape and weight-related information. In line with this, the present study hypothesized that patients with anorexia nervosa (AN) and bulimia nervosa (BN) are characterized by increased visual attention for the most dissatisfying/ugly body part compared to their most satisfying/beautiful body part, while a more balanced viewing pattern was expected for controls without eating disorders (CG).

Method

Eye movements were recorded in a group of patients with AN (n = 16), BN (n = 16) and a CG (n = 16) in an ecologically valid setting, i.e., during a 3-min mirror exposure.

Results

Evidence was found that patients with AN and BN display longer and more frequent gazes towards the most dissatisfying relative to the most satisfying and towards their most ugly compared to their most beautiful body parts, whereas the CG showed a more balanced gaze pattern.

Discussion

The results converge with theoretical models that emphasize the role of information processing in the maintenance of body dissatisfaction. Given the etiological importance of body dissatisfaction in the development of eating disorders, future studies should focus on the modification of the reported patterns.     

Body image changes associated with participation in an intensive lifestyle weight loss intervention

The primary aim of this study was to test for changes in body image in men and women enrolled in the Look AHEAD trial. Look AHEAD (Action for Health in Diabetes) is a multicenter, randomized controlled trial designed to test whether intentional weight loss reduces cardiovascular morbidity and mortality in overweight individuals with type 2 diabetes. Participants included 157 adults at one site (Pennington Biomedical Research Center (PBRC), Baton Rouge, LA) of the Look AHEAD study. At baseline, the mean BMI of the female participants was 36.4, and the mean BMI for males was 33.5. Following baseline assessment, participants were randomly assigned to the intensive lifestyle intervention (ILI, n = 81) or diabetes support and education (DSE, n = 76). The body morph assessment version 2.0 (BMA 2.0) was used to assess estimates of perceived current body size, ideal body size, acceptable body size, and body image dissatisfaction at baseline and 1 year. Over the 1 year, participants in the ILI group had significantly greater reductions in weight (10.1% for men and 8.9% for women) than those in the DSE group (+ 0.8% for men and -0.2%, for women). Perceived current body size was reduced significantly more in both men and women in the ILI group, relative to DSE. There were also significantly greater reductions in body image dissatisfaction in the ILI group, relative to the DSE group for men and women. The results of this study indicate that body image dissatisfaction improved following participation in an intensive behavioral weight loss program.     

BMI not WHR modulates BOLD fMRI responses in a sub-cortical reward network when participants judge the attractiveness of human female bodies

In perceptual terms, the human body is a complex 3d shape which has to be interpreted by the observer to judge its attractiveness. Both body mass and shape have been suggested as strong predictors of female attractiveness. Normally body mass and shape co-vary, and it is difficult to differentiate their separate effects. A recent study suggested that altering body mass does not modulate activity in the reward mechanisms of the brain, but shape does. However, using computer generated female body-shaped greyscale images, based on a Principal Component Analysis of female bodies, we were able to construct images which covary with real female body mass (indexed with BMI) and not with body shape (indexed with WHR), and vice versa. Twelve observers (6 male and 6 female) rated these images for attractiveness during an fMRI study. The attractiveness ratings were correlated with changes in BMI and not WHR. Our primary fMRI results demonstrated that in addition to activation in higher visual areas (such as the extrastriate body area), changing BMI also modulated activity in the caudate nucleus, and other parts of the brain reward system. This shows that BMI, not WHR, modulates reward mechanisms in the brain and we infer that this may have important implications for judgements of ideal body size in eating disordered individuals.     

Dieting,Exercise, or Disordered Eating Does Not Account for Extremes of Body Weight within Families

Objective : Families having both members with obesity and thin members should contain substantial information for genetics studies, provided measured phenotype is an accurate indicator of genetic predisposition. We assessed the impact of potentially complicating behavioral factors on obesity phenotypes of family members selected for a long-term project to identify genes for human obesity. Research Methods and Procedures : Ninety-nine Caucasian families were selected for study because they contained both extremely obese and average-weight family members. Family members (n = 492) were queried about their diet and exercise habits, their psychiatric histories as they pertained to eating disorders, and for a subset of subjects (n = 329), a lifetime dieting history and a lifetime maximum weight were recorded. Results : Subjects with average body weights in these families did not appear to be maintaining their weight by dieting and <4% of the average-weight subjects had ever been obese in the past. Discussion : Although dieting and other weight loss practices potentially could either mask or complicate the genotype-phenotype relationship, we found little evidence for this possibility in the families studied.     

Teasing History,Onset of Obesity,Current Eating Disorder Psychopathology,Body Dissatisfaction,and Psychological Functioning in Binge Eating Disorder

Objective: The primary goal of this study was to examine associations among teasing history, onset of obesity, current eating disorder psychopathology, body dissatisfaction, and psychological functioning in women with Binge Eating Disorder (BED). Research Methods and Procedures: Subjects were 115 female adults who met DSM‐IV criteria for BED. Measurements assessing teasing history (general appearance [GAT] and weight and size [WST] teasing), current eating disorder psychopathology (binge frequency, eating restraint, and concerns regarding eating, shape, and weight), body dissatisfaction, and psychological functioning (depression and self‐esteem) were obtained. Results: History of GAT, but not WST, was associated with current weight concerns and body dissatisfaction, whereas both GAT and WST were significantly associated with current psychological functioning. Patients with earlier onset of obesity reported more WST than patients with later onset of obesity, but the groups did not differ significantly in GAT, current eating disorder psychopathology, body dissatisfaction, or psychological functioning. Obese women reported more WST than non‐obese women, but no differences in GAT or the other outcome variables were observed. Higher frequency of GAT was associated with greater binge frequency in obese women, and with greater eating restraint in non‐obese women. Discussion: Although physical appearance teasing history is not associated with variability in most eating disorder psychopathology, it is associated with related functioning, most notably body dissatisfaction, depression, and self‐esteem. Our findings also suggest that the age of onset of obesity and current body mass index status in isolation are not associated with eating psychopathology or associated psychological functioning in adult patients with BED.     

Intrasexual competition and eating restriction in heterosexual and homosexual individuals

Restrictive eating attitudes and behaviors have been hypothesized to be related to processes of intrasexual competition. According to this perspective, within-sex competition for status serves the adaptive purpose of attracting mates. As such, status competition salience may lead to concerns of mating desirability. For heterosexual women and gay men, such concerns revolve around appearing youthful and, thus, thinner. Following this logic, we examined how exposure to high-status and competitive (but not thin or highly attractive) same-sex individuals would influence body image and eating attitudes in heterosexual and in gay/lesbian individuals. Results indicated that for heterosexuals, intrasexual competition cues led to greater body image dissatisfaction and more restrictive eating attitudes for women, but not for men. In contrast, for homosexual individuals, intrasexual competition cues led to worse body image and eating attitudes for gay men, but not for lesbian women. These findings support the idea that the ultimate explanation for eating disorders is related to intrasexual competition.     

Analysis of Attentional Bias towards Attractive and Unattractive Body Regions among Overweight Males and Females: An Eye-Movement Study

Background

Body image distortion is highly prevalent among overweight individuals. Whilst there is evidence that body-dissatisfied women and those suffering from disordered eating show a negative attentional bias towards their own unattractive body parts and others’ attractive body parts, little is known about visual attention patterns in the area of obesity and with respect to males. Since eating disorders and obesity share common features in terms of distorted body image and body dissatisfaction, the aim of this study was to examine whether overweight men and women show a similar attentional bias.

Methods/Design

We analyzed eye movements in 30 overweight individuals (18 females) and 28 normal-weight individuals (16 females) with respect to the participants’ own pictures as well as gender- and BMI-matched control pictures (front and back view). Additionally, we assessed body image and disordered eating using validated questionnaires.

Discussion

The overweight sample rated their own body as less attractive and showed a more disturbed body image. Contrary to our assumptions, they focused significantly longer on attractive compared to unattractive regions of both their own and the control body. For one’s own body, this was more pronounced for women. A higher weight status and more frequent body checking predicted attentional bias towards attractive body parts. We found that overweight adults exhibit an unexpected and stable pattern of selective attention, with a distinctive focus on their own attractive body regions despite higher levels of body dissatisfaction. This positive attentional bias may either be an indicator of a more pronounced pattern of attentional avoidance or a self-enhancing strategy. Further research is warranted to clarify these results.     

The effect of obesity management on body image in patients seeking treatment at medical centers

Objective: Body image dissatisfaction is common in treatment‐seeking patients with obesity. We aimed to investigate the effects of obesity management on body image in patients with obesity attending Italian medical centers for weight loss programs. Research Methods and Procedures: A total of 473 obese patients seeking treatment in 13 Italian medical centers (80% females; age, 45.9 ± standard deviation 11.0 years; BMI, 36.8 ± 5.7 kg/m²) were evaluated at baseline and after a 6‐month weight loss treatment. Body uneasiness, psychiatric distress, and binge eating were tested by Body Uneasiness Test (BUT, Part A), Symptom CheckList‐90 (SCL‐90), and Binge Eating Scale (BES), respectively. Results: At 6‐month follow‐up, the percentage weight loss was significantly higher in men (9.0 ± 6.3%) than in women (6.8 ± 7.3%; p = 0.010). Both men and women had a significant improvement in BUT Global Severity Index and in all of the BUT subscales with the exception of the Compulsive Self‐Monitoring subscale. Linear regression analysis selected baseline psychological and behavioral measures (global score of BUT and SCL‐90) and improved psychiatric distress and binge eating as independent predictors of changes in basal body dissatisfaction in females, whereas in males, changes were associated only with baseline BUT‐Global Severity Index score, binge eating, and its treatment‐associated improvement. Pre‐treatment BMI and BMI changes did not enter the regression. Discussion: Obesity treatment, even with a modest degree of weight loss, is associated with a significant improvement of body image, in both females and males. This effect depends mainly on psychological factors, not on the amount of weight loss.     

On the Relation of Attempting to Lose Weight,Restraint, and Binge Eating in Outpatients with Binge Eating Disorder

Objective: To examine the relationship among attempts to lose weight, restraint, and eating behavior in outpatients with binge eating disorder (BED). Research Methods and Procedures: Participants were 93 consecutive outpatients evaluated for a clinical trial who met Diagnostic and Statistical Manual, Fourth edition criteria for BED. The Eating Disorder Examination Interview was administered to assess attempts at weight loss, restraint, different forms of overeating, and the attitudinal psychopathology of eating disorders (i.e., concerns regarding eating, shape, and weight). In addition, the Three‐Factor Eating Questionnaire was used to assess cognitive restraint, hunger, and disinhibition. Psychometrically established measures were given to assess body dissatisfaction, depression, and self‐esteem. Results: The majority of participants (75.3%; N = 70) reported attempting to lose weight, but only 37.6% (N = 35) reported dietary restraint on at least half the days of the month. Dietary restraint and cognitive restraint were not associated with any form of binge eating or overeating. Dietary restraint and cognitive restraint were positively correlated with weight concern, shape concern, and body dissatisfaction, and negatively correlated with body mass index. To further examine the interplay between attempting to lose weight and restraint, three study groups were created: unrestrained nonattempters (21.5%, N = 20), unrestrained attempters (40.9%; N = 38), and restrained attempters (34.4%; N = 32). The three groups did not differ significantly on binge eating or other eating behaviors; however, significant differences were observed for weight concern, shape concern, and body dissatisfaction. Discussion: Attempts to lose weight and restraint are not synonymous for patients with BED. Although 75.3% of BED patients reported that they were attempting to lose weight, only 37.6% reported dietary restraint on at least half the days of the previous month. While restraint was negatively associated with body mass index, it was not related to binge eating or overeating. Our findings raise questions about prevailing models that posit restraint as a predominant factor in the maintenance of binge eating in BED.     

Body image and quality of life in post massive weight loss body contouring patients

Objective: Because post‐bariatric surgery patients undergo massive weight loss, the resulting skin excess can lead to both functional problems and profound dissatisfaction with appearance. Correcting skin excess could improve all these corollaries, including body image. Presently, few data are available documenting body image and weight‐related quality of life in this population. Research Methods and Procedures: Eighteen patients who underwent both bariatric surgery and body contouring completed our study. Both established surveys and new surveys designed specifically for the study were used to assess body perception and ideals, quality of life, and mood. Patients were surveyed at the following time‐points: pre‐body contouring (after massive weight loss) and both 3 and 6 month post‐body contouring. Statistical testing was performed using Student's t test and ANOVA. Results: The mean age of the patients was 46 ± 10 years (standard deviation). Quality of life improved after obesity surgery and was significantly enhanced after body contouring. Three months after body contouring, subjects ascribed thinner silhouettes to both current appearance and ideal body image. Body image also improved with body contouring surgery. Mood remained stable over 6 months. Discussion: Body contouring after surgical weight loss improved both quality‐of‐life measurements and body image. Initial body dissatisfaction did not correlate with mood. Body contouring improved body image but produced dissatisfaction with other parts of the body, suggesting that as patients become closer to their ideal, these ideals may shift. We further developed several new assessment methods that may prove useful in understanding these post‐surgical weight loss patients.     

Risk for Eating Disorders Modulates Startle-Responses to Body Words

Body image disturbances are core symptoms of eating disorders (EDs). Recent evidence suggests that changes in body image may occur prior to ED onset and are not restricted to in-vivo exposure (e.g. mirror image), but also evident during presentation of abstract cues such as body shape and weight-related words. In the present study startle modulation, heart rate and subjective evaluations were examined during reading of body words and neutral words in 41 student female volunteers screened for risk of EDs. The aim was to determine if responses to body words are attributable to a general negativity bias regardless of ED risk or if activated, ED relevant negative body schemas facilitate priming of defensive responses. Heart rate and word ratings differed between body words and neutral words in the whole female sample, supporting a general processing bias for body weight and shape-related concepts in young women regardless of ED risk. Startle modulation was specifically related to eating disorder symptoms, as was indicated by significant positive correlations with self-reported body dissatisfaction. These results emphasize the relevance of examining body schema representations as a function of ED risk across different levels of responding. Peripheral-physiological measures such as the startle reflex could possibly be used as predictors of females’ risk for developing EDs in the future.     

Visual Adaptation to Thin and Fat Bodies Transfers across Identity

Visual perception is highly variable and can be influenced by the surrounding world. Previous research has revealed that body perception can be biased due to adaptation to thin or fat body shapes. The aim of the present study was to show that adaptation to certain body shapes and the resulting perceptual biases transfer across different identities of adaptation and test stimuli. We designed two similar adaptation experiments in which healthy female participants adapted to pictures of either thin or fat bodies and subsequently compared more or less distorted pictures of their own body to their actual body shape. In the first experiment (n = 16) the same identity was used as adaptation and test stimuli (i.e. pictures of the participant’s own body) while in the second experiment (n = 16) we used pictures of unfamiliar thin or fat bodies as adaptation stimuli. We found comparable adaptation effects in both experiments: After adaptation to a thin body, participants rated a thinner than actual body picture to be the most realistic and vice versa. We therefore assume that adaptation to certain body shapes transfers across different identities. These results raise the questions of whether some type of natural adaptation occurs in everyday life. Natural and predominant exposure to certain bodily features like body shape – especially the thin ideal in Western societies – could bias perception for these features. In this regard, further research might shed light on aspects of body dissatisfaction and the development of body image disturbances in terms of eating disorders.     

Differential neural responses to food images in women with bulimia versus anorexia nervosa

Background

Previous fMRI studies show that women with eating disorders (ED) have differential neural activation to viewing food images. However, despite clinical differences in their responses to food, differential neural activation to thinking about eating food, between women with anorexia nervosa (AN) and bulimia nervosa (BN) is not known.

Methods

We compare 50 women (8 with BN, 18 with AN and 24 age-matched healthy controls [HC]) while they view food images during functional Magnetic Resonance Imaging (fMRI).

Results

In response to food (vs non-food) images, women with BN showed greater neural activation in the visual cortex, right dorsolateral prefrontal cortex, right insular cortex and precentral gyrus, women with AN showed greater activation in the right dorsolateral prefrontal cortex, cerebellum and right precuneus. HC women activated the cerebellum, right insular cortex, right medial temporal lobe and left caudate. Direct comparisons revealed that compared to HC, the BN group showed relative deactivation in the bilateral superior temporal gyrus/insula, and visual cortex, and compared to AN had relative deactivation in the parietal lobe and dorsal posterior cingulate cortex, but greater activation in the caudate, superior temporal gyrus, right insula and supplementary motor area.

Conclusions

Women with AN and BN activate top-down cognitive control in response to food images, yet women with BN have increased activation in reward and somatosensory regions, which might impinge on cognitive control over food consumption and binge eating.     

Body Dissatisfaction and Binge Eating in Obese Women: The Role of Restraint and Depression

Objective: This study examined the association between body dissatisfaction and binge eating, and the mediating role of restraint and depression among obese women. Research Methods and Procedures: Participants were obese women taking part in a cognitive-behavioral treatment program who completed self-report measures at baseline (n = 89) and post-treatment follow-up (n = 69). Results: At baseline, body dissatisfaction was strongly correlated with binge eating score. This was partly a direct effect and partly mediated by depression. No mediating effect of restraint was observed. Over the treatment period, a reduction in body dissatisfaction was associated with a reduction in binge-eating score. As in the cross-sectional data, there was evidence for mediation by change in depression with the greatest improvement in binge eating among those who became more restrained and less depressed. Discussion: These results suggest that it would be valuable to address psychological well-being, and especially body image, as part of the management of binge-eating behavior in obesity.     

Body Image Change in Obese and Overweight Persons Enrolled in Weight Loss Intervention Programs: A Systematic Review and Meta-Analysis

To report the results of a systematic review and meta-analysis examining whether weight loss interventions improve body image in obese/overweight individuals. Medline, Current Contents, and the Cochrane database were searched to identify studies involving obese/overweight adults who were enrolled in weight loss interventions in which body image was quantitatively assessed. Outcomes assessed were changes in body shape concern, body size dissatisfaction, and body satisfaction (intervention vs comparator/control group). Seven studies were included in the systematic review (4 in the meta-analysis). All but 1 study involved female participants only. The type of weight loss intervention varied between studies as did the type of control/comparator group. In 3 studies, there was no significant difference in body image outcomes, whereas in 4 studies, improvement in body image was significantly more pronounced in the intervention vs the control/comparator group. Meta-analysis revealed that improvements in body shape concern (standardized difference: -0.52; 95% confidence interval [CI]: -1.04 to 0.00), body size dissatisfaction (standardized difference: -0.66; 95% CI: -0.88 to -0.45), and body satisfaction (standardized difference: 0.74; 95% CI: 0.09 to 1.38) significantly favored the intervention over the comparator/control group (P<0.05). The results of this systematic review/meta-analysis lend support to the notion that weight loss interventions may improve body image. This is a noteworthy finding that has clear clinical applicability because body image affects psychological well-being and the ability of an individual to maintain weight loss. Future research should determine which weigh loss interventions are associated with optimal improvements in body image and maintenance of weight loss.     

Childhood Psychological,Physical, and Sexual Maltreatment in Outpatients with Binge Eating Disorder: Frequency and Associations with Gender,Obesity, and Eating‐Related Psychopathology

Objective: To examine rates of reported childhood maltreatment in binge eating disorder (BED), and to explore associations with obesity, gender, eating disorder features, and associated functioning. Research Methods and Procedures: Subjects were 145 consecutive outpatients with BED as defined in the Diagnostic and Statistical Manual of Mental Disorders, 4^th edition. Subjects were interviewed and they completed questionnaires to assess eating disorder features and functioning. The Childhood Trauma Questionnaire was given to assess childhood maltreatment in five domains (emotional abuse, physical abuse, sexual abuse, emotional neglect, and physical neglect). Results: A total of 83% of BED patients reported some form of childhood maltreatment. A total of 59% of BED patients reported emotional abuse, 36% reported physical abuse, 30% reported sexual abuse, 69% reported emotional neglect, and 49% reported physical neglect. There were no differences in the distribution of any form of childhood maltreatment by gender or by obesity status. The different forms of maltreatment were not associated with variability in current body mass index, binge eating, or in the attitudinal features of eating disorders. Only one of the five forms of maltreatment (physical neglect) was associated with dietary restraint in women. Emotional abuse was significantly associated with greater body dissatisfaction, higher depression, and lower self‐esteem in men and women and sexual abuse was associated with greater body dissatisfaction in men. The different forms of maltreatment were unrelated to the age at onset of overweight, dieting, or binge eating. Discussion: BED outpatients reported a wide range of childhood experiences of maltreatment that do not differ by gender or obesity status. Different forms of maltreatment were not associated with the onset of overweight, dieting, or binge eating, or with variability in current body mass index or eating disorder features (except for one association between physical neglect and dietary restraint). Reports of emotional abuse were associated with greater body dissatisfaction and depression and lower self‐esteem in men and women and sexual abuse with greater body dissatisfaction in men.     

Characteristics of Women with Persistent Thinness

Objective: Western society has become increasingly obesogenic. Despite this trend, some individuals maintain low weights throughout their lives. Little is known about the characteristics of persistently thin individuals. This study examined demographic, health, and psychiatric characteristics of women who reported having been persistently thin throughout childhood, adolescence, and adulthood. Research Methods and Procedures: Participants were 1022 female members of a population‐based twin registry. Participants completed a mail survey that included questions regarding demographics, body size in childhood, adolescence, and adulthood, health behaviors and satisfaction, disordered eating, perfectionism, and personality. In previous interview waves, participants completed diagnostic interviews assessing psychiatric and substance use disorders. Results: Persistent thinness was associated with a significantly later age at menarche, lower rates of dieting and binge eating, greater health satisfaction, higher self‐esteem, and lower perfectionism and body dissatisfaction. Discussion: Persistent thinness appears to be associated with greater well‐being in the present and a later age of menarche in the past. Whether later menarche is causally related to thinness or whether later menarche, persistent thinness, and enhanced well‐being all result from a third unmeasured variable such as high sports participation is yet to be resolved.     

Illusory Changes in Body Size Modulate Body Satisfaction in a Way That Is Related to Non-Clinical Eating Disorder Psychopathology

Historically, body size overestimation has been linked to abnormal levels of body dissatisfaction found in eating disorders. However, recently this relationship has been called into question. Indeed, despite a link between how we perceive and how we feel about our body seeming intuitive, until now lack of an experimental method to manipulate body size has meant that a causal link, even in healthy participants, has remained elusive. Recent developments in body perception research demonstrate that the perceptual experience of the body can be readily manipulated using multisensory illusions. The current study exploits such illusions to modulate perceived body size in an attempt to influence body satisfaction. Participants were presented with stereoscopic video images of slimmer and wider mannequin bodies viewed through head-mounted displays from first person perspective. Illusory ownership was induced by synchronously stroking the seen mannequin body with the unseen real body. Pre and post-illusion affective and perceptual measures captured changes in perceived body size and body satisfaction. Illusory ownership of a slimmer body resulted in participants perceiving their actual body as slimmer and giving higher ratings of body satisfaction demonstrating a direct link between perceptual and affective body representations. Change in body satisfaction following illusory ownership of a wider body, however, was related to degree of (non-clinical) eating disorder psychopathology, which can be linked to fluctuating body representations found in clinical samples. The results suggest that body perception is linked to body satisfaction and may be of importance for eating disorder symptomology.     

Enhanced striatal dopamine release during food stimulation in binge eating disorder

Subjects with binge eating disorder (BED) regularly consume large amounts of food in short time periods. The neurobiology of BED is poorly understood. Brain dopamine, which regulates motivation for food intake, is likely to be involved. We assessed the involvement of brain dopamine in the motivation for food consumption in binge eaters. Positron emission tomography (PET) scans with [(11)C]raclopride were done in 10 obese BED and 8 obese subjects without BED. Changes in extracellular dopamine in the striatum in response to food stimulation in food-deprived subjects were evaluated after placebo and after oral methylphenidate (MPH), a drug that blocks the dopamine reuptake transporter and thus amplifies dopamine signals. Neither the neutral stimuli (with or without MPH) nor the food stimuli when given with placebo increased extracellular dopamine. The food stimuli when given with MPH significantly increased dopamine in the caudate and putamen in the binge eaters but not in the nonbinge eaters. Dopamine increases in the caudate were significantly correlated with the binge eating scores but not with BMI. These results identify dopamine neurotransmission in the caudate as being of relevance to the neurobiology of BED. The lack of correlation between BMI and dopamine changes suggests that dopamine release per se does not predict BMI within a group of obese individuals but that it predicts binge eating.     

Appetite at "high altitude" [Operation Everest III (Comex-'97)]: a simulated ascent of Mount Everest.

We hypothesized that progressive loss of body mass during high-altitude sojourns is largely caused by decreased food intake, possibly due to hypobaric hypoxia. Therefore we assessed the effect of long-term hypobaric hypoxia per se on appetite in eight men who were exposed to a 31-day simulated stay at several altitudes up to the peak of Mt. Everest (8,848 m). Palatable food was provided ad libitum, and stresses such as cold exposure and exercise were avoided. At each altitude, body mass, energy, and macronutrient intake were measured; attitude toward eating and appetite profiles during and between meals were assessed by using questionnaires. Body mass reduction of an average of 5 +/- 2 kg was mainly due to a reduction in energy intake of 4.2 +/- 2 MJ/day (P < 0.01). At 5,000- and 6,000-m altitudes, subjects had hardly any acute mountain sickness symptoms and meal size reductions (P < 0.01) were related to a more rapid increase in satiety (P < 0.01). Meal frequency was increased from 4 +/- 1 to 7 +/- 1 eating occasions per day (P < 0. 01). At 7,000 m, when acute mountain sickness symptoms were present, uncoupling between hunger and desire to eat occurred and prevented a food intake necessary to meet energy balance requirements. On recovery, body mass was restored up to 63% after 4 days; this suggests physiological fluid retention with the return to sea level. We conclude that exposure to hypobaric hypoxia per se appears to be associated with a change in the attitude toward eating and with a decreased appetite and food intake.