Visual weight status misperceptions of men: Why overweight can look like a healthy weight

Sizing up the crowd: Assessing spatial integration difficulties in body size judgements across eating disorder symptomatology

Introduction

Body size judgements are frequently biased, or inaccurate, and these errors are further exaggerated for individuals with eating disorders. Within the eating disorder literature, it has been suggested that exaggerated errors in body size judgements are due to difficulties with integration. Across two experiments, we developed a novel integration task, named the Ebbinghaus Illusion for Bodies in Virtual Reality (VR), to assess whether nearby bodies influence the perceived size of a single body. VR was used to simulate the appearance of a small crowd around a central target body.

Method and Results

In Experiment 1 (N = 412), participants were required to judge the size of a central female target within a crowd. Experiment 1 revealed an Ebbinghaus Illusion, in which a central female appeared larger when surrounded by small distractors, but comparatively smaller when surrounded by large distractors. In other words, the findings of Experiment 1 demonstrate that surrounding crowd information is integrated when judging an individual's body size; a novel measure of spatial integration (i.e., an Ebbinghaus Illusion for Bodies in VR). In Experiment 2 (N = 96), female participants were selected based on high (n = 43) and low (n = 53) eating disorder symptomatology. We examined whether the magnitude of this illusion would differ amongst those with elevated versus low eating disorder symptomatology, in accordance with weak central coherence theory, with the high symptomatology group displaying less spatial integration relative to the low group. The results of Experiment 2 similarly found an Ebbinghaus Illusion for Bodies in VR. However, illusion magnitude did not vary across high and low symptomatology groups.

Discussion

Overall, these findings demonstrate that surrounding crowd information is integrated when judging individual body size; however, those with elevated eating disorder symptomatology did not show any integration deficit on this broader measure of spatial integration.

The problem of obesity «through the eyes» of patients (results of the survey of patients of the outpatient registry)

Aim. To assess, based on the results of the questionnaire, patients' awareness of the presence, possible causes and health effects of overweight /obesity; to determine patients' self-assessment of their own weight, information about the methods used to treat the disease, adherence to therapy.Material and methods. The survey of patients of the outpatient registry was carried out as part of a face-to-face visit of inclusion in the observational study of EVA using a specially designed questionnaire. Out of 582 patients of the PROFILE registry who came for a visit in the period from 08.04.2019 to 24.03.2020, 295 people with a body mass index (BMI) were included in the study>25 kg/m2.Results. According to the BMI values, the patients of the study cohort were divided into 4 groups: 108 (36.6%) with pre-obesity, 124 (42.1%) with class I obesity, 42 (14.2%) with class II obesity, 21 (7.1%) with class III obesity. With an increase in the class of obesity, the number of patients who admit the presence of this pathology in self-assessment increases (p<0.0001): 26.6% of patients with grade I obesity, 47.6% with grade II obesity and 81% of patients with grade III obesity gave correct answers. Among the possible causes of overweight/obesity, every third patient of the study indicated physical inactivity (31.3%) and every fifth specified excessive nutrition (20.8%). The majority of patients, 244 (82.7%), believe that being overweight worsens their health, the same number of patients, 255 (86.4%), are sure that they need to lose weight. The most common (70% of responses) for weight loss patients used various dietary restrictions, fasting, only 17% of patients increased the level of physical activity. Frequent violation of the principles of rational nutrition was revealed (insufficient amount of fruits and vegetables in the diet, salting food, eating a large amount of easily digestible carbohydrates. One hundred and thirty nine (47.1%) patients noted that it was difficult for them to observe any restrictions in food, to adhere to a diethalf of all patients and 70% of patients with class III obesity experience a constant feeling of hunger. Of the 25 patients to whom pharmacotherapy was recommended, 21 (84%) people were adherent.Conclusion. Overweight and obese patients are not always critical of self-assessment of their body weight, and the main reasons for being overweight or obese considered to be inactivity and various violations of the principles of rational nutrition. The patients of the study cohort were characterized by eating disorders and half of the patients showed signs of food addiction. Recommendations for the pharmacotherapy of obesity were received by less than 10% of patients in the study cohort, while the patients' adherence to drug therapy was high.

EXPRESS: The Influence of Three-Dimensional Cues on Body Size Judgements

Research has shown that body size judgements are frequently biased, or inaccurate. Critically, judgement biases are further exaggerated for individuals with eating disorders, a finding that has been attributed to difficulties integrating body features into a perceptual whole. However, current understanding of which body features are integrated when judging body size is lacking. In this study, we examine whether individuals integrate three-dimensional (3D) cues to body volume when making body size judgements. Computer-generated body stimuli were presented in a 3D Virtual Reality (VR) environment. Participants (N = 412) were randomly assigned to one of two conditions: in one condition the to-be-judged body was displayed binocularly (containing 3D cues to body volume), in the other, bodies were presented monocularly (2D cues only). Across 150 trials, participants were required to make a body size judgement of a target female body from a third-person point of view using an unmarked visual analogue scale (VAS). It was found that 3D cues significantly influenced body size judgements. Namely, thin 3D bodies were judged smaller, and overweight 3D bodies were judged larger, than their 2D counterpart. Furthermore, to reconcile these effects, we present evidence that the two perceptual biases, regression to the mean and serial dependence, were reduced by the additional 3D feature information. Our findings increase our understanding of how body size is perceptually encoded and creates testable predictions for clinical populations exhibiting integration difficulties.

Misperception of Healthy Weight: Associations Among Weight, Body Size Satisfaction and Body Appreciation in Older Adults

Misperceived body weight in older people can affect their health and quality of life. We analysed the body image of older adults in Primary Health Care services in central Portugal, by considering participants' weight, body size satisfaction and body appreciation. This epidemiological and cross-sectional study involved 150 participants (56% women) with an average age of 74.9 years who completed questionnaires on body size and body appreciation. Forty-nine percent of participants were affected by overweight and 29% by obesity. The majority was not satisfied with their body size (71.2%), but had very high scores related to body appreciation. Around 40% of the participants with normal weight or overweight were satisfied with their body size. Multiple regression analysis revealed that both body size satisfaction and appreciation were negatively associated with obesity, but not with overweight. Older Portuguese adults are not able to assess if their weight is a risk to their health, but regardless of their perceived physical appearance, the elderly respect their body and are receptive to improving their health.

The role of social exposure in predicting weight bias and weight bias internalisation: an international study

BACKGROUND

Whilst the consequences of weight bias and weight bias internalisation (WBI) have been explored, less is known about the factors contributing to their development. Some research has explored the role of social exposure in weight bias and WBI but has been limited in its definition of exposure and focused solely on western countries. The present study therefore aimed to assess the role of social exposure defined in terms of both population and personal exposure in predicting weight bias and WBI, in an international sample.

METHODS

Participants (N = 1041) from 33 countries, aged 18-85 years completed online measures of demographics, weight bias, WBI, and population and personal social exposure. Population exposure was defined using national obesity prevalence data from the World Health Organisation to classify countries as low (obesity rates ≤19.9%; n = 162), medium (20.0-29.9%; n = 672) or high prevalence (≥30%; n = 192). Personal exposure was defined in terms of personal contact and health and attractiveness normalisation.

RESULTS

Using regression analysis, greater weight bias was significantly predicted by being younger, male, less educated, and personal exposure in terms of normalisation beliefs that thinner body types are healthier and more attractive, greater daily exposure and overall exposure to thinner friends. The strongest predictors of weight bias (adj R2 = 13%) were gender (β = -0.24, p < .001), and personal exposure in terms of normalisation beliefs that thinner body types are more attractive (β = -0.13, p = .001). The strongest predictors of WBI (adj R2 = 6%) were attractiveness normalisation (β = -0.23, p < 0.001) and participants' perceived body shape (β = -0.27, p < 0.001). Population exposure did not predict either weight bias or WBI.

CONCLUSIONS

Personal exposure is more important than population exposure in predicting both weight bias and WBI. Findings hold implications for improving the wellbeing and lived experiences of those living with overweight and obesity.

Misalignment between perceptual boundaries and weight categories reflects a new normal for body size perception

Combatting the current global epidemic of obesity requires that people have a realistic understanding of what a healthy body size looks like. This is a particular issue in different population sub-groups, where there may be increased susceptibility to obesity-related diseases. Prior research has been unable to systematically assess body size judgement due to a lack of attention to gender and race; our study aimed to identify the contribution of these factors. Using a data-driven multi-variate decision tree approach, we varied the gender and race of image stimuli used, and included the same diversity among participants. We adopted a condition-rich categorization visual task and presented participants with 120 unique body images. We show that gender and weight categories of the stimuli affect accuracy of body size perception. The decision pattern reveals biases for male bodies, in which participants showed an increasing number of errors from leaner to bigger bodies, particularly under-estimation errors. Participants consistently mis-categorized overweight male bodies as normal weight, while accurately categorizing normal weight. Overweight male bodies are now perceived as part of an expanded normal: the perceptual boundary of normal weight has become wider than the recognized BMI category. For female bodies, another intriguing pattern emerged, in which participants consistently mis-categorized underweight bodies as normal, whilst still accurately categorizing normal female bodies. Underweight female bodies are now in an expanded normal, in opposite direction to that of males. Furthermore, an impact of race type and gender of participants was also observed. Our results demonstrate that perceptual weight categorization is multi-dimensional, such that categorization decisions can be driven by ultiple factors.

Sex differences in weight perception and weight gain among Black college students in the USA

Objectives

The aims of this study were to examine the prevalence of overweight/obesity and to explore sex differences in body weight perceptions and correlates of weight gain among Black students at 2 historically Black colleges and universities (HBCUs) in the USA.

Methods

Participants completed a paper-based survey, and their height and weight were measured (67% completion rate).

Results

The overweight and obesity rates were 33.8% and 26.9%, respectively. More females than males accurately assessed their weight (p<0.05). Body weight underestimation was associated with male sex, excellent/very good perceived overall health, and not being informed by a doctor of having overweight or obesity (p<0.01). Higher odds of ≥5% weight gain were related to female sex, living on campus, and not being informed by a doctor of having overweight or obesity (p<0.05).

Conclusion

Given the high overweight and obesity rates among Black students, HBCUs in the USA should develop intervention strategies for the prevention and management of overweight and obesity. College health educators at HBCUs need to provide regular check-ups or health screenings that help male students perceive their weight accurately and prevent weight underestimation. It is important for HBCUs to monitor and address weight gain among Black students as early as possible.

Body size perception, knowledge about obesity and factors associated with lifestyle change among patients, health care professionals and public health experts

Background

The attitudes towards obesity may have an important role on healthier behavior. The goal of the present study was to explore the attitudes towards obesity and to investigate how these attitudes were associated with lifestyle-changing behavior among the patients attending primary care centers, health care professionals and public health experts.

Methods

This cross-sectional survey study was performed in 10 primary care offices in different regions in Lithuania and in 2 public health institutions. Nine hundred thirty-four patients, 97 nurses, 65 physicians and 30 public health experts have filled the questionnaire about attitudes towards obesity and presented data about lifestyle-changing activities during last 12 months. The attitudes were compared between different respondent groups and factors associated with healthier behaviors were analyzed among overweight/obese individuals in our study population.

Results

Participants failed to visually recognize correct figure corresponding to male and female with obesity. Majority of respondents’ perceived obesity as a risk factor for heart diseases and diabetes but had less knowledge about other diseases associated with weight. About one third of respondents changed their lifestyle during last 12 months. Overweight individuals with age < 45 years (OR 1.64, 1.06–2.55; p = 0.025) were more likely and those who overestimated current weight (OR 0.44, 0.20–0.96; p = 0.036) less likely to change their lifestyle. Disappointment with their current weight (OR 2.57, 1.36–4.84; p = 0.003) was associated with healthier behavior among participants with obesity.

Conclusion

Participants had similar body size perception and knowledge about obesity. Younger age had significant association with lifestyle changing behavior among overweight individuals and disappointment with current weight among obese participants.

The impact of body diversity vs thin-idealistic media messaging on health outcomes: an experimental study

The recent rise in body dissatisfaction and weight bias has led to a call to the media to increase the diversity of their imagery, in efforts to challenge the thin-ideal. Therefore, this study aimed to evaluate the effects of both body diversity and thin-ideal interventions on health outcomes. Female participants (n = 160) were randomly allocated into an intervention group: body diversity; thin-ideal; control. They completed measures of body satisfaction, body compassion, internalisation of the thin-ideal, weight bias and behavioural intentions at baseline and post-intervention. The results showed significant differences between groups for weight bias and intentions to eat healthily. Specifically, those in the body diversity intervention group reported a greater reduction in weight bias compared to the other conditions. Further, those in the thin-ideal intervention group reported a greater increase in intentions to eat healthily compared to the other conditions. There were no differences between groups for body satisfaction, body compassion, internalisation of the thin-ideal and behavioural intentions to exercise and manage weight. In conclusion, exposure to body diversity images reduced weight bias whereas exposure to the thin-ideal promoted intentions towards healthy eating. These findings therefore offer empirical evidence for the impact of using different types of imagery to change different health outcomes.

Muscles and the Media: A Natural Experiment Across Cultures in Men's Body Image

An increasing number of studies are evidencing relationships between the drive for muscularity and potentially harmful behavioral strategies, such as unhealthy dieting and steroid use amongst men in WEIRD (Western, Educated, Industrialized, Rich, Democratic) populations. As such Western appearance standards proliferate around the world via the media, men who live in other cultural contexts are also at risk of potentially negative effects from aspiring to the “muscular ideal.” However, few studies have explored these relationships in non-WEIRD populations. We investigated men’s body ideals and body image in two non-WEIRD, non-White populations, Uganda (Africa) and Nicaragua (Central America), and compared them with an ethnically diverse sample of men in the United Kingdom. We also examined whether socio-cultural factors including media and ethnicity, predicted the drive for muscularity and body change behaviors among our participants. Results showed that Ugandan men had the least desire for muscularity relative to men in the United Kingdom. Supporting the Tripartite model we found that media and peer influences significantly predicted the drive for muscularity, particularly among men from White British and Nicaraguan Miskitu ethnic groups. By contrast, Creole / Garifuna and Mestizo men from Nicaragua were more likely to want to increase muscularity relative to Black African men from Uganda. Overall, our findings support previous research in demonstrating that there are cultural differences in the kind of body men desire, and that men from WEIRD and non-WEIRD populations may experience similar pressures to aspire to and attain a muscular body type.

'I'd say I'm fat, I'm not obese': obesity normalisation in urban-poor South Africa

OBJECTIVE

In the past decade, South Africa's obesity epidemic has increased in both children and adults, and being overweight is becoming the norm. Several contributing factors lead to the normalisation of obesity. One of these is the culturally entrenched likeness of larger body sizes or shapes within a milieu of easily accessible unhealthy food and beverages. This qualitative study advances knowledge about the influence of socio-cultural norms and obesogenic environments on weight under estimation and 'obesity normalisation' amongst black South Africans living in an urban setting.

DESIGN

A theory-based qualitative study used focus group discussions (FGDs) with a semi-structured interview guide. FGDs were transcribed verbatim and analysed thematically using a constant comparison method.

SETTING

Soweto, Johannesburg, South Africa, is a setting which has undergone rapid urbanisation and nutrition transition with ubiquitous availability of processed and fast-foods.

PARTICIPANTS

Adults older than 18 years living in Soweto (n 57).

RESULTS

There is a wide misperception about obesity amongst black Africans living in an urban setting in Soweto. Participants who admitted to being fat or overweight did not view themselves as such. This could be attributed to unchanging socio-cultural factors that reinforce the acceptability of bigger bodies and living in obesogenic environment.

CONCLUSIONS

Without addressing socio-cultural norms that attribute bigger bodies to beauty and wealth, motivating individuals to address weight gain will prove difficult especially for populations living in obesogenic environments. A multi-faceted strategy is required to address obesity in urban South African settings.

Looking at the Figures: Visual Adaptation as a Mechanism for Body-Size and -Shape Misperception

Many individuals experience body-size and -shape misperception (BSSM). Body-size overestimation is associated with body dissatisfaction, anxiety, depression, and the development of eating disorders in individuals who desire to be thinner. Similar symptoms have been noted for those who underestimate their muscularity. Conversely, individuals with high body mass indices (BMI) who underestimate their adiposity may not recognize the risks of or seek help for obesity-related medical issues. Although social scientists have examined whether media representations of idealized bodies contribute to the overestimation of fat or underestimation of muscle, other scientists suggest that increases in the prevalence of obesity could explain body-fat underestimation as a form of renormalization. However, these disparate approaches have not advanced our understanding of the perceptual underpinnings of BSSM. Recently, a new unifying account of BSSM has emerged that is based on the long-established phenomenon of visual adaptation, employing psychophysical measurements of perceived size and shape following exposure to "extreme" body stimuli. By inducing BSSM in the laboratory as an aftereffect, this technique is rapidly advancing our understanding of the underlying mental representation of human bodies. This nascent approach provides insight into real-world BSSM and may inform the development of therapeutic and public-health interventions designed to address such perceptual errors.

Perceptual Not Attitudinal Factors Predict the Accuracy of Estimating Other Women's Bodies in Both Women With Anorexia Nervosa and Controls

Disturbance in how one's body shape and size is experienced, usually including over-estimation of one's own body size, is a core feature of the diagnostic criteria of anorexia nervosa (AN). Is this over-estimation specific to women with AN's judgments of their own body? Or is it just a general feature of their judgments about all bodies? If the latter, it would be consistent with a general error in the perception of body size potentially linked to the use of a different set of visual cues for judging body size. If the former, then this suggests that the over-estimation of own body size has a strong attitudinal component and may be part of the psycho-pathology of their condition. To test this hypothesis, 20 women with AN and 80 control observers estimated the body size of 46 women. The results show a strong effect of perceptual factors in estimating body size for both controls and women with AN. This result is consistent with size over-estimation of own body in AN having a strong attitudinal basis and being a core feature of the psycho-pathology of the condition.

The Role of BMI Group on the Impact of Weight Bias Versus Body Positivity Terminology on Behavioral Intentions and Beliefs: An Experimental Study

This experimental study investigated the role of BMI on the impact of weight bias vs body positivity terminology on behavioral intentions and beliefs about obesity. Participants (n = 332) were randomly allocated to two conditions to receive a vignette depicting an image of a person with obesity using either weight bias (n = 164) or body positivity (n = 168) terminology. Participants were divided into three groups based upon their BMI category (normal weight n = 173; overweight n = 92; obese n = 64). They then completed measures of behavioral intentions, obesity illness beliefs, and fat phobia. Although there were several differences in beliefs by BMI group, the results showed no differences between weight bias or body positivity terminology on any measures. There were, however, significant BMI group by condition interactions for beliefs about obesity relating to personal control and treatment control. Post hoc tests showed that weight bias resulted in reduced personal control in the obese BMI group compared to other participants. Weight bias also resulted in higher personal control over obesity in normal weight individuals compared to body positivity. People with obesity reported higher treatment control when exposed to weight bias compared to overweight participants, whereas normal weight participants reported greater treatment control when exposed to body positivity compared to both other groups. To conclude, the impact of weight bias and body positivity information is not universal and varies according to the BMI of the audience and the outcome being measured; whereas people of normal weight may benefit from weight bias there is no evidence that obese people benefit from body positivity. Implications for the prevention and treatment of obesity are discussed.

The high-level basis of body adaptation

Prolonged visual exposure, or 'adaptation', to thin (wide) bodies causes a perceptual aftereffect such that subsequently seen bodies appear wider (thinner) than they actually are. Here, we conducted two experiments investigating the effect of rotating the orientation of the test stimuli by 90° from that of the adaptor. Aftereffects were maximal when adapting and test bodies had the same orientation. When they differed, the axis of the perceived distortion changed with the orientation of the body. Experiment 1 demonstrated a 58% transfer of the aftereffect across orientations. Experiment 2 demonstrated an even greater degree of aftereffect transfer when the influence of low-level mechanisms was reduced further by using adaptation and test stimuli with different sizes. These results indicate that the body aftereffect is mediated primarily by high-level object-based processes, with low-level retinotopic mechanisms playing only a minor role. The influence of these low-level processes is further reduced when test stimuli differ in size from adaptation stimuli.

Body size estimation of self and others in females varying in BMI

Previous literature suggests that a disturbed ability to accurately identify own body size may contribute to overweight. Here, we investigated the influence of personal body size, indexed by body mass index (BMI), on body size estimation in a non-clinical population of females varying in BMI. We attempted to disentangle general biases in body size estimates and attitudinal influences by manipulating whether participants believed the body stimuli (personalized avatars with realistic weight variations) represented their own body or that of another person. Our results show that the accuracy of own body size estimation is predicted by personal BMI, such that participants with lower BMI underestimated their body size and participants with higher BMI overestimated their body size. Further, participants with higher BMI were less likely to notice the same percentage of weight gain than participants with lower BMI. Importantly, these results were only apparent when participants were judging a virtual body that was their own identity (Experiment 1), but not when they estimated the size of a body with another identity and the same underlying body shape (Experiment 2a). The different influences of BMI on accuracy of body size estimation and sensitivity to weight change for self and other identity suggests that effects of BMI on visual body size estimation are self-specific and not generalizable to other bodies.

Visual body size norms and the under-detection of overweight and obesity

Objectives

The weight status of men with overweight and obesity tends to be visually underestimated, but visual recognition of female overweight and obesity has not been formally examined. The aims of the present studies were to test whether people can accurately recognize both male and female overweight and obesity and to examine a visual norm-based explanation for why weight status is underestimated.

Methods

The present studies examine whether both male and female overweight and obesity are visually underestimated (Study 1), whether body size norms predict when underestimation of weight status occurs (Study 2) and whether visual exposure to heavier body weights adjusts visual body size norms and results in underestimation of weight status (Study 3).

Results

The weight status of men and women with overweight and obesity was consistently visually underestimated (Study 1). Body size norms predicted underestimation of weight status (Study 2) and in part explained why visual exposure to heavier body weights caused underestimation of overweight (Study 3).

Conclusions

The under-detection of overweight and obesity may have been in part caused by exposure to larger body sizes resulting in an upwards shift in the range of body sizes that are perceived as being visually 'normal'.

Overweight but unseen: a review of the underestimation of weight status and a visual normalization theory

Although overweight and obesity are widespread across most of the developed world, a considerable body of research has now accumulated, which suggests that adiposity often goes undetected. A substantial proportion of individuals with overweight or obesity do not identify they are overweight, and large numbers of parents of children with overweight or obesity fail to identify their child as being overweight. Lay people and medical practitioners are also now poor at identifying overweight and obesity in others. A visual normalization theory of the under-detection of overweight and obesity is proposed. This theory is based on the notion that weight status is judged relative to visual body size norms. Because larger body sizes are now common, this has caused a recalibration to the range of body sizes that are perceived as being 'normal' and increased the visual threshold for what constitutes 'overweight'. Evidence is reviewed that indicates this process has played a significant role in the under-detection of overweight and obesity. The public health relevance of the under-detection of overweight and obesity is also discussed.

Overweight or about right? A norm comparison explanation of perceived weight status

Objectives

Body‐weight norms may explain why personal evaluations of weight status are often inaccurate. Here, we tested a ‘norm comparison’ explanation of weight status perceptions, whereby personal evaluations of weight status are biased by perceived body‐weight norms.

Methods

Study 1 examined whether perceptions of how one's own body weight compares to an average person predict personal evaluations of weight status. Study 2 examined whether manipulating perceptions of how one's own body weight compares to an average person influences whether or not a person identifies their own weight status as being overweight.

Results

In Study 1, if participants rated their body weight as being similar to the body weight of an average person, they were less likely to identify their weight status as being overweight. In Study 2, participants that were led to believe that their body weight was heavier than the average person were more likely to perceive their own weight status as being overweight.

Conclusions

Personal perceptions of weight status are likely to be shaped by a ‘norm comparison’ process. As overweight becomes more normal, underestimation of weight status amongst individuals with overweight and obesity will be more common.

Weight status misperceptions among UK adults: the use of self-reported vs. measured BMI

Background

It has been suggested that a significant proportion of overweight and obese individuals underestimate their weight status and think of themselves as being a healthier weight status than they are. The present study examines the prevalence of weight status misperceptions in a recent sample of UK adults, and tests whether the use of self-reported BMI biases estimation of weight status misperceptions.

Methods

Data came from UK adults who took part in the 2013 Health Survey for England. We examined the proportion of overweight vs. normal weight (categorised using self-reported vs. measured BMI) males and females who perceived their weight as being ‘about right’, as well as how common this perception was among individuals whose waist circumference (WC) placed them at increased risk of ill health.

Results

A large proportion of overweight (according to measured BMI) women (31 %) and men (55 %) perceived their weight as being ‘about right’ and over half of participants with a WC that placed them at increased risk of future ill health believed their weight was ‘about right’. The use of self-reported (vs. measured) BMI resulted in underestimation of the proportion of overweight individuals who identified their weight as ‘about right’ and overestimation of the number of normal weight individuals believing their weight was ‘too heavy’.

Conclusions

A large proportion of UK adults who are overweight misperceive their weight status. The use of self-reported BMI data is likely to produce biased estimates of weight status misperceptions. The use of objectively measured BMI is preferable as it will provide more accurate estimates of weight misperception.

Ideal Body Size as a Mediator for the Gender-Specific Association Between Socioeconomic Status and Body Mass Index

Background. While obesity continues to rise globally, the associations between body size, gender, and socioeconomic status (SES) seem to vary in different populations, and little is known on the contribution of perceived ideal body size in the social disparity of obesity in African countries. Purpose. We examined the gender and socioeconomic patterns of body mass index (BMI) and perceived ideal body size in the Seychelles, a middle-income small island state in the African region. We also assessed the potential role of perceived ideal body size as a mediator for the gender-specific association between SES and BMI. Method. A population-based survey of 1,240 adults aged 25 to 64 years conducted in December 2013. Participants’ BMI was calculated based on measured weight and height; ideal body size was assessed using a nine-silhouette instrument. Three SES indicators were considered: income, education, and occupation. Results. BMI and perceived ideal body size were both higher among men of higher versus lower SES ( p < .001) but lower among women of higher versus lower SES ( p < .001), irrespective of the SES indicator used. Multivariate analysis showed a strong and direct association between perceived ideal body size and BMI in both men and women ( p < .001) and was consistent with a potential mediating role of perceived ideal body size in the gender-specific associations between SES and BMI. Conclusion. Our study emphasizes the importance of gender and socioeconomic differences in BMI and ideal body size and suggests that public health interventions that promote perception of healthy weight could help mitigate SES-related disparities in BMI.

Visual biases in judging body weight

OBJECTIVES

There has been a steady rise in obesity levels in Western countries, and a contributory factor is people's failure to recognize weight gain. Two important visual perceptual biases, contraction bias and Weber's law, that have hitherto been ignored in the obesity literature could contribute to this problem. Contraction bias predicts that the weight of obese bodies will be underestimated and the degree of underestimation will increase as body mass index (BMI) increases. Weber's law predicts that change in the body size will become progressively harder to detect as their BMI increases.

METHODS

In Experiment 1, 29 women participants estimated the weight of 120 women varying in their body mass. In Experiment 2, 28 women participants judged which body was the heavier in a 2-alternative forced choice paradigm.

RESULTS

In Experiment 1, as predicted the participants showed a progressive underestimation of overweight and obese bodies, β1  = 0.71, t = 26.96, p < .0001. For Experiment 2, there was a significant effect of the BMI of the bodies being judged on the just noticeable difference needed to discriminate between them: F(1, 196) = 89.39, p < .0001 for 3D bodies and F(1, 86.5) = 44.57, p < .0001 for digital photographs.

CONCLUSIONS

Normal visual perceptual biases influence our ability to determine body size: contraction bias and Weber's law mean that as bodies become overweight and obese, it is harder to judge their weight and detect any increase in size. These effects may therefore compromise people's ability to recognize weight gain and undertake compensatory weight control behaviours. Statement of contribution What is already known on this subject? It is common knowledge that obesity levels in the West are rapidly rising and that people fail to recognize weight gain. What has not been widely recognized before is that there are sound perceptual reasons for this failure. Here, we identify two such perceptual biases. What does this study add? Weber's law and contraction bias compromise people's ability to recognize weight gain. It becomes progressively harder to discriminate the size of bodies as their body mass index increases. This compromises the ability to recognize weight gain and undertake compensatory behaviours.

Visual exposure to large and small portion sizes and perceptions of portion size normality: Three experimental studies

Portion sizes of many foods have increased in recent times. In three studies we examined the effect that repeated visual exposure to larger versus smaller food portion sizes has on perceptions of what constitutes a normal-sized food portion and measures of portion size selection. In studies 1 and 2 participants were visually exposed to images of large or small portions of spaghetti bolognese, before making evaluations about an image of an intermediate sized portion of the same food. In study 3 participants were exposed to images of large or small portions of a snack food before selecting a portion size of snack food to consume. Across the three studies, visual exposure to larger as opposed to smaller portion sizes resulted in participants considering a normal portion of food to be larger than a reference intermediate sized portion. In studies 1 and 2 visual exposure to larger portion sizes also increased the size of self-reported ideal meal size. In study 3 visual exposure to larger portion sizes of a snack food did not affect how much of that food participants subsequently served themselves and ate. Visual exposure to larger portion sizes may adjust visual perceptions of what constitutes a 'normal' sized portion. However, we did not find evidence that visual exposure to larger portions altered snack food intake.

"Champion" behavior in a community obesity reduction program: Feedback from peers

Current interventions to reduce obesity have limited success. This study aimed to determine the characteristics of successful champions (non health professional/community leaders) and to assess how these relate to acceptability ratings of an obesity reduction intervention-the Waist Disposal Challenge. A total of 200 peer participants completed questionnaires. Positive ratings of champions' performance were significantly correlated with perceptions of the success and suitability of the Waist Disposal Challenge. The qualitative feedback concurred that the program prompted weight loss and was a positive social experience which resulted in actual behavioral changes. Selecting suitable champions is likely to influence the success of such community health programs.

Visual exposure to obesity: Experimental effects on attraction toward overweight men and mate choice in females

BACKGROUND

Cultural differences in ideal body weight are well established, but less research has examined attraction toward potential mates of heavier body weights. We examined whether exposure to obesity increases physical attraction toward overweight men.

METHODS

In Studies 1 and 2, we examined the effect that exposure to obese vs healthy weight men had on female attraction toward an overweight man. Study 3 examined whether females who are regularly exposed to males of heavier body weights reported a greater attraction toward overweight men. Study 4 tested whether females in an online dating study were more likely to choose to date an overweight man, after having been exposed to obesity.

RESULTS

Exposure to obesity altered visual perceptions of what normal and therefore healthy body weights were and this resulted in greater attraction toward an overweight man (Studies 1 and 2). Females regularly exposed to men of heavier body weight reported a greater attraction toward overweight men (Study 3). After exposure to obesity, females in an online dating study were more likely to choose to date an overweight man ahead of a healthy weight man (Study 4).

CONCLUSIONS

Exposure to male obesity increases female attraction toward overweight men and may affect mate choice.

Visual perceptions of male obesity: a cross-cultural study examining male and female lay perceptions of obesity in Caucasian males

Background

Obesity is now common and this may have altered visual perceptions of what constitutes a ‘normal’ and therefore healthy weight. The present study examined cross-cultural differences in male and female participants’ ability to visually identify the weight status of photographed Caucasian males.

Methods

Five hundred and fifty three male and female young adults from the US (high obesity prevalence), UK and Sweden (lower obesity prevalence) participated in an online study. Participants judged the weight status of a series of photographed healthy weight, overweight and obese (class I) Caucasian males and rated the extent to which they believed each male should consider losing weight.

Results

There was a strong tendency for both male and female participants to underestimate the weight status of the photographed overweight and obese males. Photographed males were frequently perceived as being of healthier weight than they actually were. Some modest cross-cultural differences were also observed; US participants were worse at recognising obesity than UK participants (p < 0.05) and were also significantly more likely to believe that the photographed obese males did not need to consider losing weight, in comparison to both the UK and Swedish participants (ps < 0.05). No cross-cultural differences were observed for perceptions or attitudes towards the photographed healthy weight or overweight males.

Conclusions

The weight status of overweight and obese (class I) Caucasian males is underestimated when judged by males and females using visual information alone. This study provides initial evidence of modest cross-cultural differences in attitudes toward, and the ability to recognise, obesity in Caucasian males.