The mirror’s curse: Weight perceptions mediate the link between physical activity and life satisfaction among 727,865 teens in 44 countries

Purpose:The present study aimed to examine the link between physical activity(PA)and life satisfaction in a large international study of adolescents.We also aimed to test whether overweight and underweight perceptions act as mediators and whether age and sex acted as moderators.Methods:For this purpose,we analyzed data from the Health Behavior in School-aged Children study,which comprises 727,865 observations from 44 nations at 4 measurement occasions.Results:Multilevel analyses revealed a positive link between PA and life satisfaction.In addition,underweight and overweight perceptions mediated the effect of PA on life satisfaction.We further found that age and sex acted as moderators.In older adolescents,stronger effects were found in the links between PA and life satisfaction,PA and overweight perception,and both weight perceptions and life satisfaction.In addition,in female adolescents,the link between overweight perception and life satisfaction was stronger.Conversely,the links between PA and both weight perceptions were stronger for boys.Conclusion:The results suggest that weight perception explains part of the relationship between PA and life satisfaction in adolescents and that these effects vary as a function of age and sex.

Weight Perception and Diet Behavior of Japanese and Russian Adolescent Girls

Niigata City in Japan and Khabarovsk City in Russia signed a sister city agreement in 1965 and have been interacting with each other for a long time. We have been conducting comparative research on the elderly between the two cities, but there is no research on the young. Distorted perception of body weight and unnecessary dieting behavior in adolescent girls is considered a problem in both Japan and Russia. Therefore, the purpose of this study was to clarify the distortion of weight perception and diet behavior of adolescent girls in both the countries. In addition, it was decided to investigate the eating habits of people in both the countries. In total, 195 15-year-old girls from Niigata, Japan (October 2020) and 286 girls from Khabarovsk, Russia (February 2017) were surveyed. The questionnaire used was an excerpt from the World Health Organization survey on the health behavior of school-age children. The proportion of Japanese adolescent girls who perceived themselves as overweight (distorted body weight perception) was 60.5%, which was significantly higher than that of Russian adolescent girls at 30.1% (p < 0.001). In addition, the prevalence of weight loss behavior in Japan was 34.9% (n = 68), which was significantly higher than that in Russia with 27.3% (n = 78) (p < 0.001). Adolescent girls in Japan had more serious problems with weight perception, but had fewer problems with breakfast and vegetable intake habits than those in Russia. From a young age, perception of correct body shape and establishment of eating habits are important not only for current health but also for future health. We need to carefully educate adolescent girls that their body undergoes major changes through secondary sexual characteristics during adulthood.

A Survey on Simulation for Weight Perception in Virtual Reality

Virtual reality (VR) technology can provide users with an immersive experience as if they are in the real world, which can be applied in the fields of entertainment, education and scientific research, etc. In order to improve the sense of presence and immersion in VR, the design of multimodal feedback is an important component. In particular, the simulation of weight of virtual objects poses many challenges due to the limitations of hardware and software. Many researchers focused on this issue in various ways. These methods are mainly divided into two categories: device-based simulation and software-based simulation. This paper investigates the focus of software-based simulation, particularly for the virtual feedback methods proposed by researchers in recent years. We introduce the background of these proposed methods, technical implementation principles, application scenarios, the advantages and disadvantages of these simulation methods, and the evaluation criteria. We also propose the future challenges and the development of simulation methods for weight perception of virtual objects in VR.

Gender Differences in the Prevalence of Overweight and Obesity,Associated Behaviors,and Weight-related Perceptions in a National Survey of Primary School Children in China

Objective To in vestigate potential gender differences in the odds of overweight/obese, weight-related perceptions, and behaviors among Chinese school children. Methods Height, weight, and a survey of weight-related perceptions and behaviors were measured in a nationally representative survey of 12,811 children in primary schools in China. Logistic regression analyses were used to assess gender differences, adjusting for confounders. Results Boys had higher odds of being overweight/obese compared to girls within both urban [adjusted odds ratio （OR） 2.30, 95% CI 2.00 to 2.65] and rural areas （OR = 1.85, 95% CI 1.55 to 2.20）. Girls reported healthier diets （e.g., daily vegetables OR = 0.79, 95% CI 0.73 to 0.85） whereas boys consumed fried food （OR = 1.21, 95% CI 1.06 to 1.38） and sugar-sweetened drinks more often （OR = 1.49, 95% CI 1.34 to 1.65）. Gender differences included higher odds of boys perceiving themselves as overweight if they had more highly educated mothers （OR = 1.35, 95% CI 1.09 to 1.68）, less educated fathers （OR = 0.79, 95% CI 0.63 to 0.99）, and if they frequently consumed carbonated drinks （OR = 1.48, 95% CI 1.07 to 2.05）. Conclusion Childhood obesity prevention in China should be gender-focused, particularly for boys who reported an unhealthier diet but were less likely to see they were fat, even though more boys were overweight or obese than girls.

Darks and Stripes:Effects of Clothing on Weight Perception

In many societies,appearing slim(corresponding to a small body-mass index)is considered attractive.The fashion industry has been attempting to cater to this trend by designing outfits that can enhance the appearance of slimness.Two anecdotal rules,widespread in the world of fashion,are to choose dark clothes and avoid horizontal stripes,in order to appear slim.Thus far,empirical evidence has been unable to conclusively determine the validity of these rules,and there is consequently much controversy regarding the impact of both color and patterns on the visual perception of weight.In this paper,we aim to close this gap by presenting the results from a series of large-scale crowdsourcing studies that investigate the above two claims.We gathered a dataset of around 1000 images of people from the Web together with their ground-truth weight and height as well as clothing attributes about colors and patterns.To elicit the effects of colors and patterns,we asked crowd workers to estimate the weight in each image.For the analysis,we controlled potential confounds by matching images in pairs where the two images differ with respect to color or pattern,but are similar with respect to other relevant aspects.We created image pairs in two ways:firstly,observationally,i.e.,from two real images;and secondly,experimentally,by manipulating the color or pattern of clothing in a real image via photo editing.Based on our analysis,we conclude that dark clothes indeed decrease perceived weight slightly but statistically significantly,and horizontal stripes have no discernible effect compared to solid light-colored clothes.These results contribute to advancing the debate around the effect of specific clothing colors and patterns and thus provide empirical grounds for everyday fashion decisions.Moreover,our work gives an outlook on the vast opportunities of using crowd sourcing in the modern fashion industry.

Parental perception of child's weight,their attitudes towards child's dietary habits and the risk of obesity

Background The association between parental perception of child's weight and their attitudes towards his/her dietary habits has not been reported yet.This study aimed to assess the association between parental underestimation of child's weight and parental attitudes towards child's dietary habits.Methods We conducted a cross-sectional analysis of SENDO cohort participants recruited between January 2015 and June 2020.All information was collected through online questionnaires completed by parents.We calculated crude and multivariable-adjusted odds ratio(OR)and 95%confidence intervals(CI)for unhealthy attitudes towards child's dietary habits associated with parental underestimation of child's weight.Results Sixteen percent of children in the SENDO project had parents who underestimated their weight.Parents who under-estimated their child's weight status were more likely to have unhealthy attitudes toward his/her dietary habits[OR 3.35;95%CI(1.71-6.53)].Conclusions Parental underestimation of child's weight was associated with unhealthy attitudes towards child's dietary hab-its.Pediatricians and public health practitioners should pay attention to the parental perception of child's weight to identify parents who underestimate it as an at-risk group in which to inquire about lifestyle and dietary habits.

Semi-Supervised Intracranial Aneurysm Segmentation from CTA Images via Weight-Perceptual Self-Ensembling Model

Segmentation of intracranial aneurysm(IA)from computed tomography angiography(CTA)images is of significant importance for quantitative assessment of IA and further surgical treatment.Manual segmentation of IA is a labor-intensive,time-consuming job and suffers from inter-and intra-observer variabilities.Training deep neural networks usually requires a large amount of labeled data,while annotating data is very time-consuming for the IA segmentation task.This paper presents a novel weight-perceptual self-ensembling model for semi-supervised IA segmentation,which employs unlabeled data by encouraging the predictions of given perturbed input samples to be consistent.Considering that the quality of consistency targets is not comparable to each other,we introduce a novel sample weight perception module to quantify the quality of different consistency targets.Our proposed module can be used to evaluate the contributions of unlabeled samples during training to force the network to focus on those well-predicted samples.We have conducted both horizontal and vertical comparisons on the clinical intracranial aneurysm CTA image dataset.Experimental results show that our proposed method can improve at least 3%Dice coefficient over the fully-supervised baseline,and at least 1.7%over other state-of-the-art semi-supervised methods.

Relationship between parent perception of child anthropometric phenotype and body mass index change among children with developmental disabilities

Background Preschool-age children with developmental disabilities(DD)have higher prevalence of obesity than children without DD.This study aimed to explore the relationship between parent perception of their children's anthropometric phe-notype and child body mass index(BMI)z score change over one school year among preschoolers with DD.Methods The analysis consisted of a subsample(N=64)of children with DD from a larger randomized controlled trial to test an obesity prevention program in the childcare center setting.Parents ranks their child's anthropometric phenotype on a visual silhouette chart on a scale from 1(underweight)to 7(obese)and that rank score is compared to their BMI z score change over one school year.Results The majority(75%)of parents with an obese child underestimated their child's anthropometric phenotype while 7%parents with a non-obese child overestimated.Parent overestimation of child anthropometric phenotype status is associated with increased BMI z score change over 1 school year among preschool-age children with disabilities.Conclusion Parental overestimation of child anthropometric phenotype status was associated with weight gain in preschool children with DD after one school year.