The relationship of female physical attractiveness to body fatness

Exploring Within-Gender Differences in Friendships Using an Online Social Network

People tend to befriend others similar to themselves, generating a pattern called homophily. However, existing studies on friendship patterns often rely on surveys that assess the perspective of relatively few participants on their friendships but do not measure actualized friendship patterns. Here, we used data from a large Slovakian online social network to assess the role of gender, age, and body mass index (BMI) in same-gender online connections among more than 400,000 users. We found that age and BMI homophily occurred in both men's and women's same-gender connections, but somewhat more strongly among men's. Yet, as women diverged in BMI, their connections were less likely to be reciprocated. We discuss how the evolutionary legacy of men's coalitional competition (e.g., warfare) and women's mating competition or recruitment of allocare providers might contribute to these patterns in modern same-gender relationships. For example, men's engagement in physical activities may lead to similar formidability levels among their same-gender peers. Altogether, our findings highlight the importance of trait similarity to same-gender friendship patterns.

Gait pattern can alter aesthetic visual impression from a third-person perspective

Beauty is related to our lives in various ways and examining it from an interdisciplinary approach is essential. People are very concerned with their appearance. A widely accepted beauty ideal is that the thinner an individual is, the more beautiful they are. However, the effect of continuous motion on body form aesthetics is unclear. Additionally, an upright pelvic posture in the sagittal plane during walking seems to affect the aesthetic judgments of female appearance. We directly analyzed the influence of body form and walking pattern on aesthetic visual impressions from a third-person perspective with a two-way analysis of variance. Captured motion data for three conditions-upright pelvis, normal pelvis, and posteriorly tilted pelvic posture-were applied to each of three mannequins, representing thin, standard, and obese body forms. When participants watched stimulus videos of the mannequins walking with various postures, a significantly higher score for aesthetic visual impression was noted for an upright pelvic posture than for a posteriorly tilted pelvic posture, irrespective of body form (F(2, 119) = 79.89, p < 0.001, η2 = 0.54). These findings show that the third-person perspective of beauty can be improved even without being thin by walking with an upright pelvic posture.

Physical attractiveness and cardiometabolic risk

OBJECTIVES

There is only limited evidence suggesting that physical attractiveness and individuals' actual health are causally linked. Past studies demonstrate that characteristics related to physical attractiveness are more likely to be present in healthy individuals, including those with better cardiovascular and metabolic health, yet many of these studies do not account for individuals' initial health and socioeconomic characteristics, which are related to both physical attractiveness and later life health.

METHODS

We use panel survey data from the National Longitudinal Study of Adolescent to Adult Health in the United States to examine the relationship between interviewer-rated in-person physical attractiveness and actual cardiometabolic risk (CMR) based on a set of relevant biomarkers: LDL cholesterol, glucose mg/dL, C-reactive protein, systolic and diastolic blood pressure, and resting heart rate.

RESULTS

We identify a robust relationship between individuals' physical attractiveness and 10-year follow up actual health measured by the levels of CMR. Individuals of above-average attractiveness appear to be noticeably healthier than those who are described as having average attractiveness. We find that individuals' gender and race/ethnicity do not have a major effect on the described relationship. The link between physical attractiveness and health is affected by interviewers' main demographic characteristics. We carefully address the possibility of confounders affecting our results including sociodemographic and socioeconomic characteristics, cognitive and personality traits, initial health problems and BMI.

CONCLUSION

Our findings are largely in line with the evolutionary perspective which assumes that physical attractiveness is linked to individuals' biological health. Being perceived as physically attractive might also imply, among other aspects, high levels of satisfaction with life, self-confidence and ease of finding intimate partners, all of which can positively affect individuals' health.

Distress and impacts on daily life from appearance changes due to cancer treatment: A survey of 1,034 patients in Japan

This study aimed to clarify the psychosocial difficulties and impacts that cancer patients face from appearance changes, in order to develop a patient support program. An online survey was administered to patients registered with an online survey company who met the eligibility criteria. The study population was randomly selected from gender and cancer types to create a sample that reflected the proportion of cancer incidence rates in Japan as much as possible. Out of a total of 1034 respondents, 601patients (58.1%) experienced appearance change. Symptoms that were reported to have a high distress level and prevalence rate, and that widely required provision of information were such as alopecia (22.2%), edema (19.8%) and eczema (17.8%). Distress levels and personal assistance requirements were high particularly for patients who experienced stoma placement and mastectomy. More than 40% of patients who experienced appearance change had quit or were absent from work or school, and reported that their social activities were negatively affected by the visually notable changes in their appearance. Concerns about "receiving pity from others" or about "the exposure of cancer" due to their appearance change also led patients to reduce outings (β = 0.32 and β = 0.31 respectively, p < 0.001) and social interactions with others (β = 0.34 and β = 0.36 respectively, p < 0.001) and increased the discord in human relationships (β = 0.21 and β = 0.19 respectively, p < 0.001). Results from this study indicate the areas in which more support is required from healthcare professionals, as well as the need for interventions for patient cognition to avoid maladaptive behaviors in cancer patients who experience appearance changes.

Exposure to the thin beauty ideal: Are there subliminal priming effects?

OBJECTIVE

Previous research suggested that exposure to the thin beauty ideal propagated by the media is associated with body dissatisfaction and the development of disordered eating. Given recent suggestions regarding the role of automatic processes, we aimed to enhance our understanding of automatic, unconscious responses to body pictures and the association with the internalization of the thin ideal and the severity of eating disorder symptoms.

METHOD

An affective priming task with body pictures of different weight as primes and a normal-weight body picture as target, which had to be evaluated with regard to attractiveness and desirability, was administered to healthy women with either subliminal prime presentation (Experiment 1) or conscious presentation (Experiment 2).

RESULTS

Subliminal presentation did not affect the evaluation of the normal-weight target, although strength of evaluative shifts was significantly associated with internalization of the thin ideal. In contrast, the conscious presentation of the ultra-thin prime decreased and of the obese prime increased desirability and attractiveness ratings of the target.

DISCUSSION

Prevention strategies focusing on the critical evaluation of the thin ideal are important. Future studies are warranted to enhance our understanding of automatic, unconscious processes in women experiencing eating disorders.

No impact of hunger on male perception of female physical attractiveness in relation to adiposity: a randomized controlled trial

BACKGROUND

Female physical attractiveness is strongly related to body mass index (BMI). Females with lower BMI are on average more attractive down to at least BMI = 18. Previous correlational studies have indicated that this effect may be modulated by the hunger of the rater, with more hungry raters preferring images of subjects with greater adiposity. This prior work, however, was correlational and so we wished to explore this phenomenon further using a randomized controlled trial.

METHODS AND SUBJECTS

Two studies are presented. In the first, 52 male participants were recruited and after an overnight fast were randomly allocated to either fed or starved treatments. Starved individuals continued not to feed, while fed individuals were given ad libitum access to foods and were encouraged to eat to full satiation. Their hunger levels were monitored using visual analog scales (VAS) and levels of circulating glucose. Four hours later, they were asked to complete a previously used female attractiveness rating test, a standard IQ test, and a memory recall test. In the second study, which was a double-blind experiment, 32 individuals were recruited to evaluate if the original effect was due to a confounding impact of alcohol consumption when dining. Blinded individuals consumed drinks with or without alcohol. Their circulating alcohol levels were quantified by a breath test, and they repeated the tests matched with the first study excluding the IQ test.

RESULTS

Hunger resulted in lower performance on the memory recall test, but had no effect on the IQ score, and contrasting previous results had no effect on the ratings of female physical attractiveness. Circulating alcohol levels had no effect on the memory recall test, but there was a significant negative relationship between circulating alcohol and the mean adiposity of the five individuals rated as least attractive.

CONCLUSIONS

This randomized controlled trial failed to replicate previous nonrandomized observational studies, which had suggested that ratings of female physical attractiveness by males are sensitive to the levels of hunger. The reason for the difference was possibly because in previous studies, levels of hunger were confounded by alcohol consumption.

Evolutionary Theories and Men's Preferences for Women's Waist-to-Hip Ratio: Which Hypotheses Remain? A Systematic Review

Over the last 25 years, a large amount of research has been dedicated to identifying men's preferences for women's physical features, and the evolutionary benefits associated with such preferences. Today, this area of research generates substantial controversy and criticism. I argue that part of the crisis is due to inaccuracies in the evolutionary hypotheses used in the field. For this review, I focus on the extensive literature regarding men's adaptive preferences for women's waist-to-hip ratio (WHR), which has become a classic example of the just-so storytelling contributing to the general mistrust toward evolutionary explanations of human behavior. The issues in this literature originate in the vagueness and incompleteness of the theorizing of the evolutionary mechanisms leading to mate preferences. Authors seem to have rushed into testing and debating the effects of WHR on women's attractiveness under various conditions and using different stimuli, without first establishing (a) clear definitions of the central evolution concepts (e.g., female mate value is often reduced to an imprecise concept of "health-and-fertility"), and (b) a complete overview of the distinct evolutionary paths potentially at work (e.g., focusing on fecundability while omitting descendants' quality). Unsound theoretical foundations will lead to imprecise predictions which cannot properly be tested, thus ultimately resulting in the premature rejection of an evolutionary explanation to human mate preferences. This paper provides the first comprehensive review of the existing hypotheses on why men's preferences for a certain WHR in women might be adaptive, as well as an analysis of the theoretical credibility of these hypotheses. By dissecting the evolutionary reasoning behind each hypothesis, I show which hypotheses are plausible and which are unfit to account for men's preferences for female WHR. Moreover, the most cited hypotheses (e.g., WHR as a cue of health or fecundity) are found to not necessarily be the ones with the strongest theoretical support, and some promising hypotheses (e.g., WHR as a cue of parity or current pregnancy) have seemingly been mostly overlooked. Finally, I suggest some directions for future studies on human mate choice, to move this evolutionary psychology literature toward a stronger theoretical foundation.

Do the Low WHRs and BMIs Judged Most Attractive Indicate Better Health?

It is widely claimed that in well-nourished populations, very low female waist-hip ratios (WHRs) together with low body mass indices (BMIs) are judged attractive by men because these features reliably indicate superior health and fertility. However, studies show that mortality rates are higher in women with low BMIs than in women with average BMIs and are inversely related to BMI in subsistence populations. Measures of current health in women of reproductive age have not been similarly studied. We analyze large U.S. samples of reproductive-age women and show that controlling for other factors known to affect health, those with low BMIs (<20), WHRs, or waist/stature ratios did not have better health than those with values in the middle range, and there was no relationship between subsequent health outcomes and BMI in early adulthood. Lower self-reported BMIs were linked to poorer health and an increased risk of infection. However, based on recent U.S. natality data, primiparas with lower BMIs had a lower risk of an operative delivery and of gestational hypertension. Beyond these two parity-restricted effects, relevant studies and new tests fail to support the view that women with the very low BMIs and WHRs consistently judged attractive are generally healthier than women with average values; significant correlations were consistently in the opposite direction.

Beauty and the Body of the Beholder: Raters' BMI Has Only Limited Association with Ratings of Attractiveness of the Opposite Sex

OBJECTIVE

Assortative mating for adiposity increases the genetic burden on offspring, but its causes remain unclear. One hypothesis is that people who have high adiposity find other people with obesity more physically attractive than lean people.

METHODS

The attractiveness of sets of images of males and females who varied in adiposity were rated by opposite sex subjects (559 males and 340 females) across 12 countries.

RESULTS

There was tremendous individual variability in attractiveness ratings. For female attractiveness, most males favored the leanest subjects, but others favored intermediate fatness, some were indifferent to body composition, and others rated the subjects with obesity as most attractive. For male images rated by females, the patterns were more complex. Most females favored subjects with low levels of adiposity (but not the lowest level), whereas others were indifferent to body fatness or rated the images depicting individuals with obesity as the most attractive. These patterns were unrelated to rater BMI. Among Caucasian males who rated the images of the thinnest females as being more attractive, the magnitude of the effect depended on rater BMI, indicating limited "mutual attraction."

CONCLUSIONS

Individual variations in ratings of physical attractiveness were broadly unrelated to rater BMI and suggest that mutual attraction is an unlikely explanation for assortative mating for obesity.

Character of Gluteal Region Morphology in Young Chinese Females

BACKGROUND

The female gluteal morphology is an important secondary sexual characteristic and helps accentuate and define the female body shape. Despite the increasing prevalence of gluteal augmentations in our country, little data exist regarding the morphology of the gluteal region in young Chinese females. This study analyzed a convenience sample of Chinese females and their gluteal region.

METHODS

Data, measurements, and photos of the following parameters were taken: age, weight, height, and body mass index (BMI). Morphology was classified into four types: A shape, V shape, round shape, and square shape. Aesthetic characteristics of each buttock were recorded. Height, weight, BMI, and gluteal projection ratio differences in different shape groups were analyzed.

RESULTS

The study sample consisted of 103 women, with ages from 23 to 27 years. The V-shaped buttock was not found in this sample. The A shape, square shape, and round shape occupied 55.3%, 38.8%, and 5.8% accordingly. Short infragluteal fold, supragluteal fossettes, lateral depression, and V-shaped crease appeared in 42.7%, 14.6%, 11.7%, and 2.9% of samples, respectively. Of the 103 samples, 39 (37.9%) fulfilled the aesthetic gluteal projection(ratio ≥ 2). The average BMI was statistically significant between each gluteal shape (P = 0.009). Height, weight, and gluteal projection ratio showed no significant difference with the buttock shapes.

CONCLUSIONS

We are the first to describe gluteal morphology in young Chinese woman using gluteal anthropometrics. The findings of the study may provide a guideline for plastic surgeons who perform gluteal augmentation in Asian patients.

On the origin of obesity: identifying the biological, environmental and cultural drivers of genetic risk among human populations

Genetic predisposition to obesity presents a paradox: how do genetic variants with a detrimental impact on human health persist through evolutionary time? Numerous hypotheses, such as the thrifty genotype hypothesis, attempt to explain this phenomenon yet fail to provide a justification for the modern obesity epidemic. In this critical review, we appraise existing theories explaining the evolutionary origins of obesity and explore novel biological and sociocultural agents of evolutionary change to help explain the modern-day distribution of obesity-predisposing variants. Genetic drift, acting as a form of 'blind justice,' may randomly affect allele frequencies across generations while gene pleiotropy and adaptations to diverse environments may explain the rise and subsequent selection of obesity risk alleles. As an adaptive response, epigenetic regulation of gene expression may impact the manifestation of genetic predisposition to obesity. Finally, exposure to malnutrition and disease epidemics in the wake of oppressive social systems, culturally mediated notions of attractiveness and desirability, and diverse mating systems may play a role in shaping the human genome. As an important first step towards the identification of important drivers of obesity gene evolution, this review may inform empirical research focused on testing evolutionary theories by way of population genetics and mathematical modelling.

Sex matters: The effects of biological sex on adipose tissue biology and energy metabolism

Adipose tissue is a complex and multi-faceted organ. It responds dynamically to internal and external stimuli, depending on the developmental stage and activity of the organism. The most common functional subunits of adipose tissue, white and brown adipocytes, regulate and respond to endocrine processes, which then determine metabolic rate as well as adipose tissue functions. While the molecular aspects of white and brown adipose biology have become clearer in the recent past, much less is known about sex-specific differences in regulation and deposition of adipose tissue, and the specific role of the so-called pink adipocytes during lactation in females. This review summarises the current understanding of adipose tissue dynamics with a focus on sex-specific differences in adipose tissue energy metabolism and endocrine functions, focussing on mammalian model organisms as well as human-derived data. In females, pink adipocytes trans-differentiate during pregnancy from subcutaneous white adipocytes and are responsible for milk-secretion in mammary glands. Overlooking biological sex variation may ultimately hamper clinical treatments of many aspects of metabolic disorders.