Shared norms and their explanation for the social clustering of obesity

Peer effects and health impacts of different body cognitive biases in children: micro evidence from China

Background

In China, children commonly display body cognitive biases, which constitute a significant yet hidden public health issue. These biases potentially jeopardize children's well-being, hinder the cultivation of human capital, and impede societal progress. However, limited research employs theoretical analysis and econometric testing to investigate the formation of different body cognitive biases among Chinese children and their health impacts.

Methods

Based on a local average network model for theoretical analysis, this study utilizes a sample of 4,289 children from four phases of the China Health and Nutrition Survey (CHNS) conducted from 2004 to 2011. Utilizing Logit and IV Probit models, systematically evaluate the peer effect, heterogeneity of effects, and health impacts of children's different body cognitive biases.

Results

(1) The peer effect contributes to the development of light- and heavy-body cognitive biases in Chinese children. (2) The heterogeneity analysis shows that the peer effect of body cognitive biases is more significant in rural and female children. (3) The influence of heavy-body cognitive bias is more pronounced in adolescent children. (4) The "eating-activity balance" is disrupted by the two body cognitive biases in children, leading to deviations from normal body type. (5) Specifically, the light-body cognitive bias leads children to intake more and burn fewer calories, increasing their risk of obesity. (6) Conversely, the heavy-body cognitive bias prompts children to intake less and expend more calories, resulting in a higher prevalence of thinness.

Discussion

This study innovates by exploring peer effects on body cognitive biases in Chinese children, elucidating their direction and health implications. While overweight and obesity are recognized as overt health issues, the spread and impact of implicit issues like body cognitive biases should not be overlooked. Nevertheless, the issue is largely neglected in developing countries, such as China, where existing children's health policies are inadequate in addressing it. Promoting accurate body image perception and understanding of health prevention strategies among children requires adequate attention to peer effects.

A Novel Approach to Characterize State-level Food Environment and Predict Obesity Rate Using Social Media Data: Correlational Study

BACKGROUND

Community obesity outcomes can reflect the food environment to which the community belongs. Recent studies have suggested that the local food environment can be measured by the degree of food accessibility, and survey data are normally used to calculate food accessibility. However, compared with survey data, social media data are organic, continuously updated, and cheaper to collect.

OBJECTIVE

The objective of our study was to use publicly available social media data to learn the relationship between food environment and obesity rates at the state level.

METHODS

To characterize the caloric information of the local food environment, we used food categories from Yelp and collected caloric information from MyFitnessPal for each category based on their popular dishes. We then calculated the average calories for each category and created a weighted score for each state. We also calculated 2 other dimensions from the concept of access, acceptability and affordability, to build obesity prediction models.

RESULTS

The local food environment characterized using only publicly available social media data had a statistically significant correlation with the state obesity rate. We achieved a Pearson correlation of 0.796 between the predicted obesity rate and the reported obesity rate from the Behavioral Risk Factor Surveillance System across US states and the District of Columbia. The model with 3 generated feature sets achieved the best performance.

CONCLUSIONS

Our study proposed a method for characterizing state-level food environments only using continuously updated social media data. State-level food environments were accurately described using social media data, and the model also showed a disparity in the available food between states with different obesity rates. The proposed method should elastically apply to local food environments of different sizes and predict obesity rates effectively.

The influence of social relationships and activities on the health of adults with obesity: A qualitative study

BACKGROUND

Obesity in adults is a leading health challenge that causes millions of deaths worldwide and represents a risk factor for developing long-term conditions. Social relationships are one of the multiple drivers shaping obesity and obesity-related practices. However, there is still little evidence as to the processes by which relationships influence the adoption of positive and negative obesity health-related practices-eating, physical activity and alcohol intake. This study aims first to identify the types of relationships relevant to the adoption of practices in adults with obesity and, second, to explore the type of activities these relationships engage with or promote to produce those practices and their potential health consequences.

METHODS

Nineteen adults who have or had a history of obesity living in the United Kingdom were interviewed between May 2020 and March 2021. Experiences were explored through semi-structured interviews and network mapping via videoconferencing. Data were analysed using a hermeneutic phenomenology informed thematic analysis.

RESULTS

Three main themes were identified: (1) everyday familial routines matter, (2) chasing healthier lifestyles: comparing, modelling and connecting emotionally with friends and (3) healthcare professionals as negative influencers.

DISCUSSION AND CONCLUSIONS

Findings show how different types of relationships might shape the risk of developing and losing weight. They uncover the power of informal networks (family and friends) and highlight the potentially negative impact of formal ones (healthcare professionals). Our exploration could add to arguments about the need for stakeholders confronting obesity to be aware of the relevance of everyday social relationships in health and well-being strategies for tackling the issue, in creating collective and individual person-centred long-term sustainable actions.

PATIENT AND PUBLIC CONTRIBUTION

Feedback on the tone/content of the interview questions was provided by the two first participants. The results were checked and received feedback from one of the interviewees.

Spatial spillovers, living environment and obesity in France: Evidence from a spatial econometric framework

In 2019, obesity affected 17% of French adults. In this article, we use a unique data set that combines individual-level health and consumption data with living environment data (food, sports and health amenities). We develop a spatial econometric framework to address French health disparities in obesity prevalence across space. We find that regulations on fast food restaurant locations could be a policy instrument to counter the prevalence of obesity. We also establish the existence of spatial spillovers of sports and medical amenities on obesity. This new evidence points to the need to consider a wider context than just the immediate local environment in the fight against the obesity pandemic.

While Some Things Change, Do Others Stay the Same? The Heterogeneity of Neighborhood Health Returns to Gentrification

Gentrification is associated with decreases in neighborhood poverty and crime, increases in amenities and services, among other benefits-all identified as structural determinants of health. However, gentrification is also associated with population-level replacement of the existing community, or threats thereof. Combining census data from the ten largest MSAs in the U.S. with tract-level estimates from the CDC-PLACES Project from 2013-14 to 2017-18, we explore how the changing socioeconomic conditions in gentrifying neighborhoods correlate with changes in neighborhood health. We find significant differences between gentrifying and non-gentrifying neighborhoods in their associations with neighborhood health. The sociodemographic changes occurring in gentrifying neighborhoods generally correspond with simultaneous decreases in aggregate health risk behaviors and negative health outcomes. However, these changes are heterogeneous and complex. Whether and how neighborhood health changes alongside other components of neighborhood change depends on whether gentrification occurs in majority Black, Hispanic, or White neighborhoods. Our findings provide preliminary evidence that the changes accompanying gentrification extend to neighborhood health, but the direction of influence varies by neighborhood composition, type of sociodemographic change, specific health outcome, and spatial spillover. We discuss theoretical implications for future work addressing the mechanisms driving changes in neighborhood health, and potential approaches that differentiate policy responses.

Fat stigma and body objectification: A text analysis approach using social media content

This study investigates how female and male genders are positioned in fat stigmatising discourses that are being conducted over social media. Weight-based linguistic data corpus, extracted from three popular social media (SM) outlets, Twitter, YouTube and Reddit, was examined for fat stigmatising content. A mixed-method analysis comprising sentiment analysis, word co-occurrences and qualitative analysis, assisted our investigation of the corpus for body objectification themes and gender-based differences. Objectification theory provided the underlying framework to examine the experiential consequences of being fat across both genders. Five objectifying themes, namely, attractiveness, physical appearance, lifestyle choices, health and psychological well-being, emerged from the analysis. A deeper investigation into more facets of the social interaction data revealed overall positive and negative attitudes towards obesity, which informed on existing notions of gendered body objectification and weight/fat stigmatisation. Our findings have provided a holistic outlook on weight/fat stigmatising content that is posted online which can further inform policymakers in planning suitable props to facilitate more inclusive SM spaces. This study showcases how lexical analytics can be conducted by combining a variety of data mining methods to draw out insightful subject-related themes that add to the existing knowledge base; therefore, has both practical and theoretical implications.

Social alienation of adolescents with obesity in classrooms: A multilevel approach

INTRODUCTION

Adolescents with obesity are more likely to be isolated by peers, but whether they also choose to disengage from their peers remains unclear.

METHODS

This study examined a sample of 646 adolescents between the age of 13 and 16 across 34 classrooms in 3 junior high schools in Taiwan, with data collected from May to June 2019. The sociometric network nomination method assessed peer relationships, such as unpopularity, unsociability, and alienation. Multilevel models were applied to explore the extent to which the class-level prevalence of overweight and obesity and peer support moderate the relationship between student-level obesity and peer relationships.

RESULTS

Overall, students with obesity were more likely to experience unpopularity, unsociability, and alienation from their peers in classroom settings (adjusted odds ratio [AOR] = 1.904, 2.208, 2.777, p < .05). Regardless of their obesity status, students in high classroom peer support were less likely to report unsociability (AOR = 0.124, p < .05). No cross-level interactions were observed, indicating that students with obesity did not experience a reduction of peer rejection in high peer support classrooms. Neither did obese students in classrooms with higher rates of overweight and obesity.

CONCLUSIONS

Students with obesity were more likely to experience interpersonal problems. Classroom peer support can increase peer acceptance for typical students but has no beneficial influence on adolescents with weight problems. Classroom peer support needs to be directed to become adequate support for students with obesity.

Exploring Obesity as a Gendered Contagion: Impact on Lifestyle Interventions to Improve Cardiovascular Health

PURPOSE

Obesity increases the risk of cardiovascular disease. Lifestyle interventions such as physical activity and diet are important components for reducing the risk of obesity. Data suggest that lifestyle choices differ between men and women, as well as in groups. The purpose of this review was to explore whether obesity can be considered as a gendered social contagion, associated with differences in lifestyle and response to lifestyle interventions in men and women.

FINDINGS

There are important sex-based differences of obesity to consider. There is evidence that peers have an influence on lifestyle preferences such as physical activity level and dietary habits, but the evidence is inconclusive if the differences exist between men and women. Similarly, data from lifestyle intervention studies are not conclusive whether there are differences between men and women. There is not enough evidence for the notion that obesity is a gendered social contagion.

IMPLICATIONS

More research is needed to understand differences in lifestyle and lifestyle interventions between men and women, especially across the life span, which could have profound public health implications.

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.

Best Practices for Modeling Egocentric Social Network Data and Health Outcomes

OBJECTIVE/AIM

We describe best practices for modeling egocentric networks and health outcomes using a five-step guide.

BACKGROUND

Social network analysis (SNA) is common in social science fields and has more recently been used to study health-related topics including obesity, violence, substance use, health organizational behavior, and healthcare utilization. SNA, alone or in conjunction with spatial analysis, can be used to uniquely evaluate the impact of the physical or built environment on health. The environment can shape the presence, quality, and function of social relationships with spatial and network processes interacting to affect health outcomes. While there are some common measures frequently used in modeling the impact of social networks on health outcomes, there is no standard approach to social network modeling in health research, which impacts rigor and reproducibility.

METHODS

We provide an overview of social network concepts and terminology focused on egocentric network data. Egocentric, or personal networks, take the perspective of an individual who identifies their own connections (alters) and also the relationships between alters.

RESULTS

We describe best practices for modeling egocentric networks and health outcomes according to the following five-step guide: (1) model selection, (2) social network exposure variable and selection considerations, (3) covariate selection related to sociodemographic and health characteristics, (4) covariate selection related to social network characteristics, and (5) analytic considerations. We also present an example of SNA.

CONCLUSIONS

SNA provides a powerful repertoire of techniques to examine how relationships impact attitudes, experiences, and behaviors-and subsequently health.

Impact of perceptions of body size on obesity and weight management behaviour: a large representative population study in an African setting

BACKGROUND

Perception of body size is an important psycho-cultural cause of obesity with wide racial and ethnic variations.

METHOD

Cross-sectional household survey using multistage cluster-randomised sampling. Prevalence estimates were weighted. Logistic regressions were done to determine the impact of perception of large body size on obesity and the impact of perception of own body size on weight-management behaviour. Adjusted odds ratios (AOR) were reported.

RESULTS

The survey involved 6628 adults from 2843 households. More than a quarter of the population is either obese or overweight. Nearly half, 44.07% (95% confidence interval [CI]: 42.48-45.66%) of the population perceive large body size as desirable. Positive perception of large body size significantly increases the odds of obesity by 1.5 (AOR: 1.45; 95% CI: 1.09-1.9). Some 42.03% (95% CI: 35.52-48.55%) obese persons misperceive their weight to be normal. Perceiving own body size as normal decreases the odds of weight-losing behaviour (AOR: 0.019; 95% CI: 0.014-0.026).

CONCLUSION

There is a high level of veneration of large body size in southeast Nigeria, and this has a significant impact on obesity burden. Perception of own body size has a significant impact on weight-management behaviour. Health-promotion policies aimed at changing the social desirability of large body size and misperception of body size are recommended.

First-year college students' weight change is influenced by their randomly assigned roommates' BMI

BACKGROUND

There is ongoing debate about whether friends' greater similarity in Body Mass Index (BMI) than non-friends is due to friend selection, shared environments, or peer influence.

METHODS

First-year college students (n = 104) from a southwestern U.S. university were randomly assigned roommates during the university's housing process, effectively removing friend selection effects. Participant BMI was measured up to four times (T1-T4) across 2015-2016. The influence of roommate baseline BMI (T1) on change in participant BMI over time (T2-T4) was analyzed using a linear mixed effects model adjusted for individual socio-demographics, linear time trends, baseline BMI, and physical clustering of students. A sensitivity analysis examining floormates was also conducted.

RESULTS

Consistent with roommate influence, participants randomized to roommates with a higher BMI gained more weight between times T2 and T4 (β = 0.06; 95% CI = 0.02, 0.10). No shared environment effects (shared campus or floor) were found.

CONCLUSIONS

Randomly assigned roommates influenced each other's weight trajectories. This clarifies that BMI convergence can occur outside of friend selection or shared environments mechanisms.

Evaluating Potential Behavioral Mediators for Increasing Similarity in Friends' Body Size among College Students

College students and their friends become more similar in weight status over time. However, it is unclear which mediators explain this relationship. Using validated survey measures of diet, physical activity, alcohol intake, sleep behaviors, mental health, and food security status, we take a comprehensive look at possible factors associated with excess weight gain that may explain friends’ convergence on body mass index (BMI), waist circumference, waist to hip ratio, and waist to height ratio over time. We use linear mixed models applied to a longitudinal dataset of first-year college students to examine whether these variables satisfy two criteria for potential candidate mediators of friends’ influence on anthropometrics—cross-sectional similarity among friends (n = 509) and longitudinal associations with increasing anthropometrics (n = 428). While friends were similar on some survey measures (such as dining hall use, home cooked meal consumption, fruit intake, alcohol intake, hours of sleep, and stress). Only dining hall use and stress emerged as potential explanations for why friends’ BMI and anthropometric change may be similar. Given that only a few variables satisfied the two criteria as potential mediators, future research may need to consider alternative measurement approaches, including real-time assessments, objective measurements, and alternative factors causing the convergence of friends’ and college students’ body size over time.

Contributions of personality to social influence: Contingent associations between social network body size composition and BMI

Social influence is a key determinant of health behaviors and outcomes. Research in the social network tradition emphasizes social structural mechanisms like network content (i.e., the degree to which particular attitudes, attributes, or behaviors are present in the network) and social proximity (i.e., opportunities for social interaction). In contrast, psychologists are oriented toward the individual, identifying how personality traits like self-monitoring affect susceptibility to peer pressure. Here, we integrate social network and personality approaches, examining social influence on body size using surveys of 379 adults with dependent children. Our findings suggest that the association between social network body size composition and respondent BMI is contingent on both individual susceptibility to influence (i.e., high self-monitoring) and social proximity (i.e., opportunities for co-eating). These results indicate that individuals embedded in social networks bring unique sets of social skills and orientations to interactions, potentially influencing the flow of content across networks.

Friendship as a social mechanism influencing body mass index (BMI) among emerging adults

Background

Social relationships have been proposed as a significant factor shaping obesity risk. The first year of college, a period of major social, behavioral, and weight changes, provides a context well-suited to tracking longitudinally the impact of shifting friendships on weight outcomes. This study sought to identify social mechanisms impacting BMI change among emerging adults.

Methods

An analytic sample of 276 college students (71.0% female, 52.2% non-White) provided repeated reports of relationships and BMI was measured up to four times during 2015–2016. Stochastic actor-oriented models were used to examine change in BMI through social influence and change in friendships over time, controlling for sex and race/ethnicity.

Results

At baseline, mean BMI was 24.2±4.5 kg/m². Overall, mean BMI increased over time; individual decreases in BMI were uncommon. There was a selection effect of BMI: participants with BMIs between 22 and 26 kg/m² were most likely to be nominated as a friend. While participants did not select friends based on BMI similarity, participants who were reported as friends were more likely to experience convergence in BMI over time relative to the BMIs of non-friends (p = 0.015). An increase in BMI (versus stability or a decrease) was more likely for those whose friends had a higher BMI on average compared to participants whose friends had the same or lower BMI (OR = 2.85, 95% CI = 1.22, 6.71).

Conclusion

Analyses indicated BMI affected friend selection, not through students selecting friends with similar BMI, but rather, by students avoiding friends with more extreme BMI levels.

Cluster-based network proximities for arbitrary nodal subsets

The concept of a cluster or community in a network context has been of considerable interest in a variety of settings in recent years. In this paper, employing random walks and geodesic distance, we introduce a unified measure of cluster-based proximity between nodes, relative to a given subset of interest. The inherent simplicity and informativeness of the approach could make it of value to researchers in a variety of scientific fields. Applicability is demonstrated via application to clustering for a number of existent data sets (including multipartite networks). We view community detection (i.e. when the full set of network nodes is considered) as simply the limiting instance of clustering (for arbitrary subsets). This perspective should add to the dialogue on what constitutes a cluster or community within a network. In regards to health-relevant attributes in social networks, identification of clusters of individuals with similar attributes can support targeting of collective interventions. The method performs well in comparisons with other approaches, based on comparative measures such as NMI and ARI.

The role of partner autonomy support in motivation, well-being, and weight loss among women with higher baseline BMI

INTRODUCTION

The association of partner autonomy support with women's motivation for healthy eating, weight-related health behavior change, and psychological well-being has been largely overlooked. Results of 2 studies showed that the positive association between autonomy support and a variety of motivational and psychological outcomes was especially pronounced for women with high body mass index (BMI) (+1 SD) compared to low BMI (-1 SD).

METHOD

In Study 1, autonomy support was measured as male partners' report of their behavior in a cross-sectional design. In Study 2, autonomy support was measured as female participants' perceptions of their partners' behavior in a longitudinal home environment-based behavioral weight loss intervention.

RESULTS

Study 1 showed that autonomy support from partners was associated with greater self-determined motivation for healthy eating and self-reported well-being among women with higher BMI. Study 2 showed that changes in partner autonomy support over 18 months of a home-based weight loss intervention were associated with increases in motivation for treatment and greater weight loss, especially for women who had higher baseline BMI.

DISCUSSION

Both studies demonstrated that autonomy support was associated with adaptive functioning across weight status but that it was especially potent for women with higher BMI. This pattern of findings is explained in terms of the pressures women with higher BMI may feel about their weight-related behaviors. (PsycINFO Database Record

Social network body size is associated with body size norms of South Asian adults

Aims

To examine the association between social network body size and body size norms in South Asian adults.

Methods

Participants (n = 766) from the Mediators of Atherosclerosis in South Asians Living in America (MASALA) study (2014-2018) provided detailed information about their five closest network members. Participants' perceptions of their network members' body sizes, their own body size (self-body size), and a healthy body size for men and women (body size norms) were assessed using the Stunkard 9-figure scale. Adjusted hierarchical linear regression models were used to examine associations between the average body size of network members and perceived body size norms.

Results

Participants' average age was 59.1 years (SD = 9.2) and 44.1% were women. Participants reported an average network body size of 4.0 (SD = 1.1). The average body size norm for male and female Stunkard images was 3.6 (SD = 1.0) and 3.4 (SD = 0.8), respectively. Social network body size was positively associated with increasing body size norms (β-coefficient = 0.31, 95% CI: 0.26, 0.36), independent of self-body size.

Discussion

Social networks may influence body size norms in South Asian adults. Long-term follow up of the MASALA cohort will determine if social network body size and body size norms are associated with weight- control behaviors and weight change.

Associations between local descriptive norms for overweight/obesity and insufficient fruit intake, individual-level diet, and 10-year change in body mass index and glycosylated haemoglobin in an Australian cohort

Background

Descriptive norms (what other people do) relate to individual-level dietary behaviour and health outcome including overweight and obesity. Descriptive norms vary across residential areas but the impact of spatial variation in norms on individual-level diet and health is poorly understood. This study assessed spatial associations between local descriptive norms for overweight/obesity and insufficient fruit intake (spatially-specific local prevalence), and individual-level dietary intakes (fruit, vegetable and sugary drinks) and 10-year change in body mass index (BMI) and glycosylated haemoglobin (HbA_1c).

Methods

HbA_1c and BMI were clinically measured three times over 10 years for a population-based adult cohort (n = 4056) in Adelaide, South Australia. Local descriptive norms for both overweight/obesity and insufficient fruit intake specific to each cohort participant were calculated as the prevalence of these factors, constructed from geocoded population surveillance data aggregated for 1600 m road-network buffers centred on cohort participants’ residential addresses. Latent growth models estimated the effect of local descriptive norms on dietary behaviours and change in HbA_1c and BMI, accounting for spatial clustering and covariates (individual-level age, sex, smoking status, employment and education, and area-level median household income).

Results

Local descriptive overweight/obesity norms were associated with individual-level fruit intake (inversely) and sugary drink consumption (positively), and worsening HbA_1c and BMI. Spatially-specific local norms for insufficient fruit intake were associated with individual-level fruit intake (inversely) and sugary drink consumption (positively) and worsening HbA_1c but not change in BMI. Individual-level fruit and vegetable intakes were not associated with change in HbA_1c or BMI. Sugary drink consumption was also not associated with change in HbA_1c but rather with increasing BMI.

Conclusion

Adverse local descriptive norms for overweight/obesity and insufficient fruit intake are associated with unhealthful dietary intakes and worsening HbA_1c and BMI. As such, spatial variation in lifestyle-related norms is an important consideration relevant to the design of population health interventions. Adverse local norms influence health behaviours and outcomes and stand to inhibit the effectiveness of traditional intervention efforts not spatially tailored to local population characteristics. Spatially targeted social de-normalisation strategies for regions with high levels of unhealthful norms may hold promise in concert with individual, environmental and policy intervention approaches.

Increasing overweight and obesity erodes engagement in one's neighborhood by women, but not men

Obesity is socially stigmatized in the U.S., especially for women. Significant research has focused on the role that the social and built environments of neighborhoods play in shaping obesity. However, the role of obesity in shaping neighborhood social structure has been largely overlooked. We test the hypothesis that large body size inhibits an individual's engagement in his or her neighborhood. Our study objectives are to assess if (1) body size (body mass index) interacts with gender to predict engagement in one's neighborhood (neighborhood engagement) and (2) if bonding social capital interacts with gender to predict neighborhood engagement independent of body size. We used data collected from the cross-sectional 2011 Phoenix Area Social Survey (PASS), which systematically sampled residents across four neighborhood types (core urban, urban fringe, suburban, retirement) across the Phoenix Metopolitian Area. Survey data was analyzed using logistic regression for 804 participants, including 35% for whom missing data was computed using multiple imputation. We found that as body size increases, women—but not men—have reduced engagement in their neighborhood, independent of bonding social capital and other key covariates (objective 1). We did not observe the interaction between gender and bonding social capital associated with neighborhood engagement (objective 2). Prior scholarship suggests obesity clusters in neighborhoods due to processes of social, economic, and environmental disadvantage. This finding suggests bi-directionality: obesity could, in turn, undermine neighborhood engagement through the mechanism of weight stigma and discrimination.

Weight and weight control behaviors of Latinas and their social ties

OBJECTIVE

Shared behaviors have been implicated in the clustering of obesity among socially connected people. This study determined how weight and weight control behaviors of participants and their social ties are related and how these factors are associated with weight change in participants.

METHOD

Adult Latinas participating in a lifestyle intervention completed an egocentric network measure of weight and weight control behaviors. Participant weight was objectively measured at baseline and 12 months. Multivariable regression models determined the relationship between weight and weight control behaviors of participants and their social ties.

RESULTS

Participants and their social ties shared similarities in weight control behaviors and weight change. Participants who reported social ties that had lost weight were more likely to eat small portions and low-fat foods, but those with social ties that had gained weight were more likely to use herbal supplements. Participants who reported more social ties who exercised, drank liquid meal replacements, took herbal supplements, and self-weighed were more likely to lose weight whereas those with fewer social ties that exercised were more likely to gain weight. Weight loss and weight gain by social ties predicted participant weight loss and weight gain, respectively.

CONCLUSIONS

Given that weight and weight control behaviors of Latinas reflect that of their social ties, targeting existing social networks for lifestyle interventions may more effectively improve and sustain health-promoting behaviors and outcomes. (PsycINFO Database Record

René Girard and the Mimetic Nature of Eating Disorders

French historian and literary critic René Girard (1923-2015), most widely known for the concepts of mimetic desire and scapegoating, also engaged in the discussion of the surge of eating disorders in his 1996 essay Eating Disorders and Mimetic Desire. This article explores Girard's ideas on the mimetic nature and origin of eating disorders from a clinical psychiatric perspective and contextualizes them within the field of eating disorders research as well as in relation to broader psychological, sociological and anthropological models of social comparison and non-consumption. Three main themes in Girard's thinking on the topic of eating disorders are identified and explored: the 'end of prohibitions' as a driving force in the emergence of eating disorders, eating disorders as a phenomenon specific to modernity, and the significance of 'conspicuous non-consumption' in the emergence of eating disorders.

Dyadic Dynamics in a Randomized Weight Loss Intervention

BACKGROUND

Despite health and economic burdens associated with overweight and obesity, long-term weight loss intervention efforts have been largely unsuccessful. Observations that weight status tends to cluster in social groups, and findings showing "ripple" effects of weight change within social clusters, raise questions about the impact of social relationships on weight loss.

PURPOSE

Through a reanalysis of data from a randomized weight loss intervention, this study compared dyadic dynamics in intervention participants and in-home partners.

METHODS

Over the course of 18 months, data was collected from 201 pairs enrolled in either behavioral weight loss treatment (BWL) or treatment including partners and providing items to facilitate healthy choices at home (BWL + H). Using a dyadic growth curve model, covariance between baseline BMI, BMI change trajectories, and starting BMI and BMI trajectory for both the self and the other were examined.

RESULTS

There were strong indicators of dependence in the data. Baseline BMI was positively correlated for both treatment groups. In the BWL + H condition, BMI change trajectories were positively correlated. In the BWL condition, this reversed: Change trajectories were negatively correlated. Additionally, partner BMI and primary participant BMI change were positively correlated, indicating that a heavier partner at baseline related to less weight loss.

CONCLUSIONS

Social relationships exert a significant influence on weight loss outcomes. Depending on the intervention group, these influences may help (BWL + H) or hinder (BWL). It may be that home intervention changed social support and interaction in important ways and that these effects could be effectively harnessed to implement more effective interventions (NCT00200330).

Bariatric Surgery Patients and Their Families: Health, Physical Activity, and Social Support

BACKGROUND

This study evaluated the social environment of bariatric surgery patients in the preoperative period.

METHODS

Forty bariatric surgery patients (mean = 46.2 ± 11.2 years), 35 adult cohabitating family members (mean = 45.2 ± 12.7 years), and 15 cohabitating children (mean = 11.5 ± 3.6 years) were recruited from a large rural medical center. Adult participants (patients and family members) completed height, weight, body composition, blood draws, and physical activity assessments (accelerometry), as well as eating behavior and social support inventories before the patient underwent bariatric surgery. Child participants completed demographic, height, and weight assessment only.

RESULTS

Over 90 % of adult family members were overweight or obese (body mass index (BMI) ≥ 25 kg/m², as were 50 % of children (BMI percentile ≥ 85 %). More than one third (37.1 %) of family members met the criteria for moderate to severe insulin resistance. Physical activity measured by accelerometry was moderately correlated between the patient and adult family members (r = 0.46, p = 0.023). Bariatric surgery patients reported high levels of social support from their family members on multiple social support measures.

CONCLUSIONS

Many family members of bariatric surgery patients also lived with obesity and related comorbidities, and demonstrate high sedentary behavior. However, patients reported high levels of support from family members, including support in following a healthy diet and engaging in physical activity. Engaging families in behavior change may help bariatric surgery patients and their families to become healthier.

Comparing methods of targeting obesity interventions in populations: An agent-based simulation

Social networks as well as neighborhood environments have been shown to effect obesity-related behaviors including energy intake and physical activity. Accordingly, harnessing social networks to improve targeting of obesity interventions may be promising to the extent this leads to social multiplier effects and wider diffusion of intervention impact on populations. However, the literature evaluating network-based interventions has been inconsistent. Computational methods like agent-based models (ABM) provide researchers with tools to experiment in a simulated environment. We develop an ABM to compare conventional targeting methods (random selection, based on individual obesity risk, and vulnerable areas) with network-based targeting methods. We adapt a previously published and validated model of network diffusion of obesity-related behavior. We then build social networks among agents using a more realistic approach. We calibrate our model first against national-level data. Our results show that network-based targeting may lead to greater population impact. We also present a new targeting method that outperforms other methods in terms of intervention effectiveness at the population level.

•

While behavioral interventions exist for obesity, uncertainty remains about how best to target those interventions to maximize population-level impact.

•

Agent-based models are simulation tools that can be used to evaluate different targeting strategies to help policy makers.

•

Targeting intervention resources using social networks may lead to greater population impact of behavioral interventions compared to traditional methods of targeting.

Partner Influence in Diet and Exercise Behaviors: Testing Behavior Modeling, Social Control, and Normative Body Size

Previous research has documented social contagion in obesity and related health behaviors, but less is known about the social processes underlying these patterns. Focusing on married or cohabitating couples, we simultaneously explore three potential social mechanisms influencing obesity: normative body size, social control, and behavior modeling. We analyze the association between partner characteristics and the obesity-related health behaviors of focal respondents, comparing the effects of partners' body type, partners' attempts to manage respondents' eating behaviors, and partners' own health behaviors on respondents' health behaviors (physical activity, fruit and vegetable consumption, and fast food consumption). Data on 215 partners are extracted from a larger study of social mechanisms of obesity in family and community contexts conducted in 2011 in the United States. Negative binomial regression models indicate that partner behavior is significantly related to respondent behavior (p < .001), net of controls. These results are suggestive of a behavior modeling mechanism in obesity-related patterns of consumption and physical activity. In contrast, we find little support for the influence of normative body size or partner social control in this sample, though generalizations about the relevance of these processes may be inappropriate. These results underscore the importance of policies and interventions that target dyads and social groups, suggesting that adoption of exercise or diet modifications in one individual is likely to spread to others, creating a social environment characterized by mutual reinforcement of healthy behavior.

Longitudinal social networks impacts on weight and weight-related behaviors assessed using mobile-based ecological momentary assessments: Study Protocols for the SPARC study

Background

The transition from the home to college is a phase in which emerging adults shift toward more unhealthy eating and physical activity patterns, higher body mass indices, thus increasing risk of overweight/obesity. Currently, little is understood about how changing friendship networks shape weight gain behaviors. This paper describes the recruitment, data collection, and data analytic protocols for the SPARC (Social impact of Physical Activity and nutRition in College) study, a longitudinal examination of the mechanisms by which friends and friendship networks influence nutrition and physical activity behaviors and weight gain in the transition to college life.

Methods

The SPARC study aims to follow 1450 university freshmen from a large university over an academic year, collecting data on multiple aspects of friends and friendship networks. Integrating multiple types of data related to student lives, ecological momentary assessments (EMAs) are administered via a cell phone application, devilSPARC. EMAs collected in four 1-week periods (a total of 4 EMA waves) are integrated with linked data from web-based surveys and anthropometric measurements conducted at four times points (for a total of eight data collection periods including EMAs, separated by ~1 month). University databases will provide student card data, allowing integration of both time-dated data on food purchasing, use of physical activity venues, and geographical information system (GIS) locations of these activities relative to other students in their social networks.

Discussion

Findings are intended to guide the development of more effective interventions to enhance behaviors among college students that protect against weight gain during college.

Perceived size of friends and weight evaluation among low-income adolescents

Drawing from social comparison theory, we examine how perceptions of friends' body sizes may influence adolescents' subjective evaluations of their own body (e.g., how accurate they are in judging their weight, how much body dissatisfaction they feel), particularly for adolescent females. Participants were low-income, minority adolescents (Study 1: N = 194 females, Mean age = 15.4; Study 2: N = 409 males and females; Mean age = 14.9). Adolescents used figure rating scales to indicate their perceived size and that of four of their closest friends and completed several measures of subjective weight evaluation (e.g., weight classification, body dissatisfaction, internalized weight bias). In both studies, how adolescents perceived their body size and the body sizes of their thinnest and heaviest friends were positively correlated. In Study 1, overweight females based on measured BMI were less likely to accurately judge themselves as overweight if they had a close friend they perceived as heavy. In addition, females who viewed themselves as having a larger figure reported more internalized weight bias when they had friends they viewed as relatively thin. Findings from Study 2 suggest that how friends' bodies are perceived is predictive of subjective weight evaluation measures only for adolescent females. Programs that address negative aspects of social comparison may be important in preventing both obesity and eating disorder symptoms in adolescent females.

Why the Neighborhood Social Environment Is Critical in Obesity Prevention

The continuing obesity epidemic in the USA calls for the examination of antecedents to the well-known risk factors of physical activity and diet. The neighborhood built environment has been extensively studied in relation to obesity noting an increased risk of development and prevalence of obesity in relation to numerous built environment characteristics (lack of green spaces, higher number of fast food restaurants, low walkability indices). The neighborhood social environment, however, has been less extensively studied but is perhaps an equally important component of the neighborhood environment. The neighborhood social environment, particularly constructs of social capital, collective efficacy, and crime, is associated with obesity among both adults and children. Several studies have identified physical activity as a potential pathway of the neighborhood social environment and obesity association. Further work on social networks and norms and residential segregation, as well as the examination of dietary behaviors and mental health as potential mediating pathways, is necessary. Given the existing evidence, intervening on the neighborhood social environment may prove to be an effective target for the prevention on obesity. Intervention studies that promote healthy behaviors and prevent obesity while addressing aspects of the neighborhood social environment are necessary to better identify targets for obesity prevention.

Friends Like Me: Associations in Overweight/Obese Status among Adolescent Friends by Race/Ethnicity, Sex, and Friendship Type

BACKGROUND

Little is known about how interpersonal friend relationships are associated with obesity in young people, particularly with regard to how race/ethnicity, type of friendship, and sex affect the association between friends' and adolescents' weight status. This study examined associations in weight status among adolescents and their friends, exploring magnitudes of associations across friendship type, sex, and race/ethnicity.

METHODS

As part of EAT-2010 (Eating and Activity in Teens), friend nominations and anthropometrics were obtained from adolescents (n = 2099: 54% female; 80% nonwhite; mean age: 14.2 ± 1.9 years). Generalized estimating equation logistic regression models were used to test associations between adolescents' overweight/obese status and friends' (i.e., friend group, female friends, male friends, female best friends, and male best friends) overweight/obese status. Interactions by adolescent race/ethnicity were examined.

RESULTS

The majority of significant associations were observed among white female adolescents' who had a 22-40% higher prevalence of overweight/obesity if their friends were overweight compared to white females whose friends were not overweight. In contrast, there were few significant differences for other adolescent female and male racial/ethnic groups for girls and boys. Results for friend groups and best friends were generally similar to one another.

CONCLUSIONS

The association between friend and adolescent overweight/obese status depended on adolescents' sex, race/ethnicity, and friendship type. Given the similarities among friends, obesity interventions targeting youth, especially white females, should consider involving friends.

The role of social networks in the development of overweight and obesity among adults: a scoping review

BACKGROUND

Although it is increasingly acknowledged that social networks are important to our understanding ofoverweight and obesity, there is limited understanding about the processes by which such networks shapetheir progression. This paper reports the findings of a scoping review of the literature that sought to identify the key processes through which social networks are understood to influence the development of overweight and obesity.

METHODS

A scoping review was conducted. Forty five papers were included in the final review, the findings of which were synthesised to provide an overview of the main processes through which networks have been understood to influence the development of overweight and obesity.

RESULTS

Included papers addressed a wide range of research questions framed around six types of networks: a paired network (one's spouse or intimate partner); friends and family (including work colleagues and people within social clubs); ephemeral networks in shared public spaces (such as fellow shoppers in a supermarket or diners in a restaurant); people living within the same geographical region; peers (including co-workers, fellow students, fellow participants in a weight loss programme); and cultural groups (often related toethnicity). As individuals are embedded in many of these different types of social networks at any one time, the pathways of influence from social networks to the development of patterns of overweight and obesity are likely to be complex and interrelated. Included papers addressed a diverse set of issues: body weight trends over time; body size norms or preferences; weight loss and management; physical activity patterns; and dietary patterns.

DISCUSSION

Three inter-related processes were identified: social contagion (whereby the network in which people are embedded influences their weight or weight influencing behaviours), social capital (whereby sense of belonging and social support influence weight or weight influencing behaviours), and social selection (whereby a person's network might develop according to his or her weight).

CONCLUSIONS

The findings have important implications for understanding about methods to target the spread of obesity, indicating that much greater attention needs to be paid to the social context in which people make decisions about their weight and weight influencing behaviours.

Where there's smoke: Cigarette use, social acceptability, and spatial approaches to multilevel modeling

I contribute to understandings of how context is related to individual outcomes by assessing the added value of combining multilevel and spatial modeling techniques. This methodological approach leads to substantive contributions to the smoking literature, including improved clarity on the central contextual factors and the examination of one manifestation of the social acceptability hypothesis. For this analysis I use restricted-use natality data from the Vital Statistics, and county-level data from the 2005-9 ACS. Critically, the results suggest that spatial considerations are still relevant in a multilevel framework. In addition, I argue that spatial processes help explain the relationships linking racial/ethnic minority concentration to lower overall odds of smoking.

Ethnic density and obesity: evidence from fixed-effects models

We use data from the 1980 to 2004 waves of the National Longitudinal Survey of Youth, 1979 Cohort to examine the association between the ethnic density of metropolitan areas and obesity among U.S. blacks and Latinos. Although minority groups' obesity rates tend to be higher in metropolitan areas containing many co-ethnics, controlling for other areal characteristics and unobserved time-constant confounders via fixed-effects models dramatically alters this association. In the fixed-effects models, higher levels of co-ethnic density are inversely associated with black males' obesity risk and unrelated to the obesity risk of black females, Latinas, and Latino males. For most groups, marrying and having children increases the risk of obesity.

The Relationship between Social Network Body Size and the Body Size Norms of Black and Hispanic Adults

Objective

To examine the relationship between the body size norms of Black and Hispanic adults and the body sizes of their social network members.

Methods

Egocentric network data were examined for 245 adults recruited from 2012–2013 in New York City. A multivariable regression model was used to examine the relationship between participants' perception of normal body size and the body sizes of their network members adjusted for participant age, education, race/ethnicity and network size. Participants' body size norms were also examined stratified by the following characteristics of obese network members: frequency of contact, living proximity, relationship, and importance of relationship.

Results

Index participants were 89% female with mean body mass index 33.5 kg/m². There were 2571 network members identified (31% overweight, 10% obese). In the fully adjusted multivariable model, perception of normal body size increased as the number of network members with obesity increased (p < 0.01). Larger body size norms were associated with increased frequency of contact with obese network members (p = 0.04), and obese members living in the home (p = 0.049).

Conclusions

These findings support a relationship between the body size norms of Black and Hispanic adults and their social network body size.

•

Participants reported a larger body size as normal as the number of social network members with obesity increased.

•

Participants' perception of normal body size increased as frequency of contact with obese members increased.

•

Participants with obese network members living in the home perceived a larger body size as normal.

Designing mental health interventions informed by child development and human biology theory: a social ecology intervention for child soldiers in Nepal

The anthropological study of human biology, health, and child development provides a model with potential to address the gap in population-wide mental health interventions. Four key concepts from human biology can inform public mental health interventions: life history theory and tradeoffs, redundancy and plurality of pathways, cascades and multiplier effects in biological systems, and proximate feedback systems. A public mental health intervention for former child soldiers in Nepal is used to illustrate the role of these concepts in intervention design and evaluation. Future directions and recommendations for applying human biology theory in pursuit of public mental health interventions are discussed.

Rethinking animal models and human obesity

Human obesity is a complex phenomenon where economic, cultural, behavioral, and biological factors intersect in the physiological space. Developing animal models that capture several elements of the many potential interactions between these factors will only increase their translational value.

Prevalence of risk factors for the metabolic syndrome in the middle income Caribbean nation of st. Lucia

The objective of this research was to measure the presence of metabolic syndrome risk factors in a sample population in the middle income Caribbean nation of St. Lucia and to identify the demographic and behavioral factors of metabolic syndrome among the study participants. Interviews and anthropometric measures were conducted with 499 St. Lucians of ages 18-99. Descriptive statistics were used for the analysis. Fifty-six percent of females and 18 percent of males had a waist size equal to or above the indicator for the metabolic syndrome. Behavioral risk factors such as sedentary lifestyle, smoking, and alcohol consumption varied by gender. Thirty-six percent of women and 22% of men reported a sedentary lifestyle and 43% of women and 65% of men reported any alcohol consumption. More research should be done to determine the cultural norms and gender differences associated with modifiable risk behaviors in St. Lucia.

Leveraging social influence to address overweight and obesity using agent-based models: the role of adolescent social networks

The prevalence of adolescent overweight and obesity (hereafter, simply "overweight") in the US has increased over the past several decades. Individually-targeted prevention and treatment strategies targeting individuals have been disappointing, leading some to propose leveraging social networks to improve interventions. We hypothesized that social network dynamics (social marginalization; homophily on body mass index, BMI) and the strength of peer influence would increase or decrease the proportion of network member (agents) becoming overweight over a simulated year, and that peer influence would operate differently in social networks with greater overweight. We built an agent-based model (ABM) using results from R-SIENA. ABMs allow for the exploration of potential interventions using simulated agents. Initial model specifications were drawn from Wave 1 of the National Longitudinal Study of Adolescent Health (Add Health). We focused on a single saturation school with complete network and BMI data over two waves (n = 624). The model was validated against empirical observations at Wave 2. We focused on overall overweight prevalence after a simulated year. Five experiments were conducted: (1) changing attractiveness of high-BMI agents; (2) changing homophily on BMI; (3) changing the strength of peer influence; (4) shifting the overall BMI distribution; and (5) targeting dietary interventions to highly connected individuals. Increasing peer influence showed a dramatic decrease in the prevalence of overweight; making peer influence negative (i.e., doing the opposite of friends) increased overweight. However, the effect of peer influence varied based on the underlying distribution of BMI; when BMI was increased overall, stronger peer influence increased proportion of overweight. Other interventions, including targeted dieting, had little impact. Peer influence may be a viable target in overweight interventions, but the distribution of body size in the population needs to be taken into account. In low-obesity populations, strengthening peer influence may be a useful strategy.

The contribution of applied social sciences to obesity stigma-related public health approaches

Obesity is viewed as a major public health concern, and obesity stigma is pervasive. Such marginalization renders obese persons a "special population." Weight bias arises in part due to popular sources' attribution of obesity causation to individual lifestyle factors. This may not accurately reflect the experiences of obese individuals or their perspectives on health and quality of life. A powerful role may exist for applied social scientists, such as anthropologists or sociologists, in exploring the lived and embodied experiences of this largely discredited population. This novel research may aid in public health intervention planning. Through these studies, applied social scientists could help develop a nonstigmatizing, salutogenic approach to public health that accurately reflects the health priorities of all individuals. Such an approach would call upon applied social science's strengths in investigating the mundane, problematizing the "taken for granted" and developing emic (insiders') understandings of marginalized populations.

Social contagion theory: examining dynamic social networks and human behavior

Here, we review the research we have conducted on social contagion. We describe the methods we have employed (and the assumptions they have entailed) to examine several datasets with complementary strengths and weaknesses, including the Framingham Heart Study, the National Longitudinal Study of Adolescent Health, and other observational and experimental datasets that we and others have collected. We describe the regularities that led us to propose that human social networks may exhibit a 'three degrees of influence' property, and we review statistical approaches we have used to characterize interpersonal influence with respect to phenomena as diverse as obesity, smoking, cooperation, and happiness. We do not claim that this work is the final word, but we do believe that it provides some novel, informative, and stimulating evidence regarding social contagion in longitudinally followed networks. Along with other scholars, we are working to develop new methods for identifying causal effects using social network data, and we believe that this area is ripe for statistical development as current methods have known and often unavoidable limitations.

Physical inactivity mediates the association between the perceived exercising behavior of social network members and obesity: a cross-sectional study

OBJECTIVES

Social networks influence the spread of depression, health behaviors, and obesity. The social networks of older urban-dwelling adults were examined to assess whether physical inactivity mediated the association between social networks and obesity.

METHODS

Data come from the Montreal Neighborhood Networks and Healthy Aging study (n=2707). Self-reported height and weight were used to calculate body mass index (BMI) with obesity defined as a BMI ≥ 30. A name generator/interpreter instrument was used to elicit participants' core ties (i.e., alters), and assess whether alters exercised regularly and resided in participants' neighborhoods. The International Physical Activity Questionnaire was used to measure physical inactivity. Separate multilevel logistic regression analyses were conducted for younger (18-54 years) and older (55 years plus) age groups to examine the association between the exercising behavior of alters and obesity. Ancillary analyses examined whether the residential location of alters was associated with obesity. Mediation analyses assessed whether physical inactivity mediated the association between alter exercising behavior and obesity. Models adjusted for participant socio-demographic and -economic characteristics.

RESULTS

Among the older age stratum (55 years plus), physically inactive individuals were more likely obese (OR 2.14; 95% CIs: 1.48-3.10); participants who had more exercising alters were less likely obese (OR: 0.85; 95% CIs: 0.72-0.99). Physical inactivity mediated the association between exercising alters and obesity. Ancillary analyses showed that having exercising alters in the neighborhood compared to other locations tended to reduce the odds of obesity.

CONCLUSION

This work demonstrates the importance of social networks among older adults in facilitating a physically active lifestyle and reducing the odds of obesity. Such findings can inform the design of public health interventions that seek to improve the environmental conditions supporting the physical activity of older adults.

Vulnerability to fat-stigma in women's everyday relationships

Obesity is understood as a major medical and public health challenge, but the stigma attached to it also creates extraordinary suffering. The pervasiveness of morally negative views toward the overweight and obese, such as laziness and lack of self-control, are undeniable in mainstream U.S. society, situated both institutionally (such as health care barriers or media stereotypes) and interpersonally (such as the negative comments of others). To test basic pathways related to the etiology of women's vulnerability to feeling "fat-stigma" in interpersonal relationships, we present a study conducted between August and November 2009 that combines social network, anthropometric, body image, and interview data for 112 women aged 18-45 years, living in Phoenix, Arizona, U.S., and linked follow-up interviews with 823 of their social ties. Based on the proposition that some social network characteristics should amplify the personal experience of stigma, and others should ameliorate it, we ask: what relationship qualities make women more sensitive to the judgments of others about their weight? We find that what others say about women has only a very limited influence on how women judge others' negative views of their weight once actual body size is taken into account, but that women are more influenced by the opinions of those they are closer to and interact with more often. Ultimately, the degree to which women perceive themselves to be judged by others regarding their weight is not well explained by the actual opinions of people in their networks, either known or unknown to them. The assumption that social network norms exert considerable influence on people's stigma experiences needs to be carefully evaluated, at least in the domain of overweight and obesity.