Beyond the "I" in the obesity epidemic: a review of social relational and network interventions on obesity

The past, present, and future of behavioral obesity treatment

Over the last century, hundreds of evaluations have been conducted to examine weight-management interventions related to diet, physical activity, and behavior therapy. These investigations have contributed to a growing body of knowledge that has consistently advanced the field of obesity treatment, while also revealing some persistent challenges. This narrative review summarizes key findings from randomized controlled trials conducted in adults that have combined diet, physical activity, and behavior therapy, an approach variously referred to as behavioral treatment, comprehensive lifestyle modification, or intensive lifestyle intervention. The review shows that current behavioral approaches induce average reductions in baseline body weight of 5 to 10% at 6 to 12 months. Such losses have proven effective in reducing the risk of type 2 diabetes in persons with impaired glucose tolerance and in improving other obesity-related complications. These benefits have also been associated with reductions in healthcare costs. Despite these advances, behavioral treatment is challenged by the need for larger losses to achieve optimal improvements in health, by difficulties associated with maintaining weight loss, and by barriers limiting access to treatment. New anti-obesity medications, when combined with behavioral obesity treatment, hold promise of addressing the first two issues.

The mediating role of children's intergenerational support in association between grandparenting and cognitive function among middle-aged and older Chinese: findings from the CHARLS cohort study

OBJECTIVES

With the world's population increasing in age, there has been a significant rise in the prevalence of cognitive impairment and dementia among individuals. This study aims to investigate the association between grandparenting and cognitive function among middle-aged and older Chinese using data from 2011 to 2018 China Health and Retirement Longitudinal Study (CHARLS). Additionally, the study seeks to explore the potential mediating effect of intergenerational support from children on this relationship, using data from the CHARLS 2011 database.

METHODS

5254 participants were recruited at the baseline survey in CHARLS 2011. Subsequently, a follow-up survey was conducted over 8 years, from CHARLS 2011 to 2018, with 1472 individuals completing the follow-up survey. The CHARLS included surveys on grandparenting and cognitive assessments. Grandparenting was categorized as yes and no. The assessment of cognitive function involved the evaluation of episodic memory and mental intactness. The present study used cross-sectional and longitudinal analyses to examine the relationship between grandparenting and cognitive function. The bootstrap method assessed the mediating effect of children's intergenerational support.

RESULTS

The results of both cross-sectional and longitudinal studies indicated a positive association between grandparenting and cognitive function in middle-aged and older Chinese (B = 0.138, p < 0.05; B = 0.218, p < 0.05). Children's emotional and economic support played intermediary roles between grandparenting and cognitive function.

CONCLUSION

The results emphasized the significance of policymakers considering the consequences of intergenerational care and family support when formulating and executing social service policies targeted at the middle-aged and older population in China.

Racial Disparities in Avoidant Coping and Hypertension Among Midlife Adults

While associations between stress and hypertension have been documented, little research has examined the association between coping and hypertension, especially in the context of understanding racial disparities. Utilizing data from the CHDS-DISPAR study, we examine the association between avoidant coping and hypertension among adults age 50 while assessing for potential differences across (1) coping in response to the general stress and discrimination and (2) African American and White racial groups. Coping was measured using a 9-item scale with an avoidant coping subscale (e.g., drinking alcohol). Mean avoidance coping scores were calculated for both general stress and discrimination. No racial differences in avoidant coping were found. Within our sample (n = 414), there was a high burden of hypertension among African American respondents compared to White respondents (50.3% vs. 22.6%). Models assessed associations between avoidant coping and hypertension adjusted for sociodemographic factors, obesity, and either experience of stress or discrimination depending on the coping domain examined. Avoidant coping in response to the general stress and discrimination was associated with increased hypertension among White respondents (PR: 1.63 [95%CI 1.01, 2.24]; PR: 1.69 [95%CI 1.12, 2.26], respectively) and no associations among African American respondents (PR: 0.83 [95%CI 0.57, 1.09]; PR: 0.82 [95%CI 0.52, 1.12], respectively). This research suggests that racial disparities in hypertension may not be attributable to individual-level coping behaviors.

Inflammasome-Mediated Cytokines: A Key Connection between Obesity-Associated NASH and Liver Cancer Progression

Liver cancer is one of the most lethal malignancies and is commonly diagnosed as hepatocellular carcinoma (HCC), a tumor type that affects about 90% of patients. Non-alcoholic steatohepatitis (NASH) and obesity are both risk factors for this disease. HCC initiation and progression are deeply linked with changes in the hepatic microenvironment, with cytokines playing key roles. The understanding of the pathogenic pathways that connect these disorders to liver cancer remains poor. However, the inflammasome-mediated cytokines associated with both diseases are central actors in liver cancer progression. The release of the pro-inflammatory cytokines IL-1β and IL-18 during inflammasome activation leads to several detrimental effects on the liver microenvironment. Considering the critical crosstalk between obesity, NASH, and HCC, this review will present the connections of IL-1β and IL-18 from obesity-associated NASH with HCC and will discuss approaches to using these cytokines as therapeutic targets against HCC.

Evidence of the Associations between Individual and Partner Autonomy Support and Physiological Stress in the Context of Conversations about Weight among Couples Who are Overweight or Obese during a 6-Month Intervention

The aim of the study was to examine the impact of supportive communication on acute physiological stress responses during weight-related conversations taking place throughout a couples' weight loss program. Participants were 47 married or cohabitating couples where each partner had a BMI of 25-40 kg/m². Couples were randomized as a dyad into a traditional weight loss program or a program that also included training in providing support to one's partner throughout the weight loss process. Structured conversations between partners about weight management were videotaped at baseline and 6 months. Participants provided saliva samples before and after the conversations, which were assayed for cortisol and salivary alpha-amylase (sAA) to determine physiological stress and anxiety responses to conversations about weight. The results indicated that receiving support from one's partner when discussing weight-related issues was associated with greater physiological stress, as indicated by higher cortisol and sAA levels, whereas providing support to one's partner was associated with lower cortisol levels and higher sAA levels. The findings suggest that receiving support is not a universally positive experience, especially for populations facing health issues. The mixed findings for support provision align with previous studies identifying a negative association between affectionate communication and cortisol levels, as well as a positive association between sAA and anxiety and emotional arousal. The findings and their implications for understanding the physiological correlates of couples' conversations about weight are discussed.

Identifying a New Social Intervention Model of Panic Buying Under Sudden Epidemic

COVID-19 that broke out at the end of 2019 continues to spread globally, with frequent occurrence of variant disease strains, thus epidemic prevention and control become a kind of routine job. At present, due to the prevention and control measures such as maintaining social distance and community blockades, there is a boom in material purchases in many places, which not only seriously endangers social order and public environmental safety, but also easily leads to the interruption of the supply chain and the shortage of social materials. This article aims to study the intervention methods to curb the spread and spread of panic buying behavior. Firstly, through crawler technology and LDA (Latent Dirichlet Allocation) topic model, this article analyzes the intervention measures taken by various social forces in China to curb the spread of panic buying, and summarizes the multi-channel intervention measures including online and offline forms. Secondly, through the multi-Agent Monte Carlo method, the targeted intervention mechanism is supplemented in each propagation link of the panic buying propagation model, and a new social intervention model of panic buying under sudden epidemic is constructed. Then, through MATLAB modeling and simulation, the main factors affecting panic buying intervention are discussed. The simulation results show that: (1) The single plan with the best intervention effect is the supply monitoring. While the official response can play an immediate inhibitory effect, but it is affected by credibility and timeliness. The intervention effect of psychological counseling is limited, and it generally needs to be used in combination with other measures. (2) The combination strategy with the best intervention effect is "supply monitoring + official response + psychological counseling," and the worst is "information review and guidance + psychological counseling." Supply monitoring is a key measure to curb panic buying. At the same time, "information review and guidance" will have a certain counter-effect in the combined strategy. Finally, the effectiveness and universality of the proposed model are verified by examples of China and Britain.

Measuring social processes regarding eating, physical activity, and weight in higher-weight people: the weight-related interactions scale (WRIS)

PURPOSE

This study sought to develop a psychometrically sound measure to assess effective and ineffective forms of input from others regarding eating, physical activity, and weight in higher-weight people, namely, the Weight-Related Interactions Scale (WRIS).

METHODS

Participants (n = 736) were adults in the overweight/obese weight ranges who completed the WRIS and measures of weight-specific social support, emotional eating, weight stigma, eating-specific self efficacy, and social desirability.

RESULTS

Exploratory and confirmatory factor analyses of the WRIS supported a three-factor solution of 'Criticism', 'Minimization', and 'Collaboration' as forms of weight-related input from others. Support was found for the reliability and the concurrent, convergent, and divergent validity of the WRIS.

CONCLUSIONS

The WRIS is a promising new instrument for comprehensively assessing the input of others in relation to eating, physical activity, and weight among higher-weight individuals.

LEVEL OF EVIDENCE

Level III. Evidence obtained from well-designed cohort or case-control analytic studies.

Interaction of Neighborhood and Genetic Risk on Waist Circumference in African-American Adults: A Longitudinal Study

BACKGROUND

Understanding determinants of metabolic risk has become a national priority given the increasingly high prevalence rate of this condition among U.S. adults.

PURPOSE

This study's aim was to assess the impact of gene-by-neighborhood social environment interactions on waist circumference (WC) as a primary marker of metabolic risk in underserved African-American adults. Based on a dual-risk model, it was hypothesized that those with the highest genetic risk and who experienced negative neighborhood environment conditions would demonstrate higher WC than those with fewer risk factors.

METHODS

This study utilized a subsample of participants from the Positive Action for Today's Health environmental intervention to improve access and safety for walking in higher-crime neighborhoods, who were willing to provide buccal swab samples for genotyping stress-related genetic pathways. Assessments were conducted with 228 African-American adults at baseline, 12, 18, and 24 months.

RESULTS

Analyses indicated three significant gene-by-environment interactions on WC outcomes within the sympathetic nervous system (SNS) genetic pathway. Two interactions supported the dual-risk hypotheses, including the SNS genetic risk-by-neighborhood social life interaction (b = -0.11, t(618) = -2.02, p = .04), and SNS genetic risk-by-informal social control interaction (b = -0.51, t(618) = -1.95, p = .05) on WC outcomes. These interactions indicated that higher genetic risk and lower social-environmental supports were associated with higher WC. There was also one significant SNS genetic risk-by-neighborhood satisfaction interaction (b = 1.48, t(618) = 2.23, p = .02) on WC that was inconsistent with the dual-risk pattern.

CONCLUSIONS

Findings indicate that neighborhood and genetic factors dually influence metabolic risk and that these relations may be complex and warrant further study.

TRIAL REGISTRATION

NCT01025726.

Using Social Media to Understand Online Social Factors Concerning Obesity: A Systematic Review (Preprint)

Background

Evidence in the literature surrounding obesity suggests that social factors play a substantial role in the spread of obesity. Although social ties with a friend who is obese increase the probability of becoming obese, the role of social media in this dynamic remains underexplored in obesity research. Given the rapid proliferation of social media in recent years, individuals socialize through social media and share their health-related daily routines, including dieting and exercising. Thus, it is timely and imperative to review previous studies focused on social factors in social media and obesity.

Objective

This study aims to examine web-based social factors in relation to obesity research.

Methods

We conducted a systematic review. We searched PubMed, Association for Computing Machinery, and ScienceDirect for articles published by July 5, 2019. Web-based social factors that are related to obesity behaviors were studied and analyzed.

Results

In total, 1608 studies were identified from the selected databases. Of these 1608 studies, 50 (3.11%) studies met the eligibility criteria. In total, 10 types of web-based social factors were identified, and a socioecological model was adopted to explain their potential impact on an individual from varying levels of web-based social structure to social media users’ connection to the real world.

Conclusions

We found 4 levels of interaction in social media. Gender was the only factor found at the individual level, and it affects user’s web-based obesity-related behaviors. Social support was the predominant factor identified, which benefits users in their weight loss journey at the interpersonal level. Some factors, such as stigma were also found to be associated with a healthy web-based social environment. Understanding the effectiveness of these factors is essential to help users create and maintain a healthy lifestyle.

Systematic review of salutogenic-oriented lifestyle randomised controlled trials for adults with type 2 diabetes mellitus

OBJECTIVE

Describe the characteristics (development, intensity, deliverers, setting, strategies) and assess the effect of salutogenic-oriented lifestyle interventions on physical and psychosocial health outcomes in adults with type 2 diabetes mellitus (T2DM).

METHOD

PubMed, Scopus and PsycINFO were systematically searched for randomised controlled trials (RCTs) published up to August 2019 that complied with predefined salutogenic criteria: the participant as a whole, the participant's active involvement and the participant's individual learning process. Characteristics of the salutogenic-oriented interventions with and without significant results were compared and qualitatively summarised.

RESULTS

Twenty-eight RCTs were identified. Salutogenic oriented interventions that significantly improved both physical and psychosocial health were characterized by being based on formative research, culturally targeted, and delivered in 10-20 sessions in group settings, whereas salutogenic oriented interventions that neither improved physical or psychosocial health significantly were characterized by being individually tailored and delivered in less than 10 group sessions in individual settings.

CONCLUSIONS

This systematic review suggests that salutogenic-oriented lifestyle interventions are effective for physical and psychosocial health in the short term. More research is needed to determine how intervention characteristics moderate (long-term) effectiveness.

PRACTICE IMPLICATIONS

The results provide a basis for purposefully developing effective salutogenic interventions for adults with T2DM.

A randomized controlled trial of a theory-based weight-loss program for couples

OBJECTIVE

Weight gain occurs during marriage, yet obesity treatment is focused on individuals. Outcomes may be improved by targeting joint weight loss and the interpersonal milieu that fosters spousal interdependence. Self-determination theory (SDT) posits that autonomy-supportive environments (e.g., promote meaningful choice, minimize control) produce better health outcomes. This trial tested an SDT-informed weight-loss intervention intended to facilitate autonomy support in couples.

METHOD

Sixty-four couples were randomized to standard behavioral weight loss (BWL) that couples attended together or to a SDT-informed weight-loss intervention (SDT-WL) that aimed to bolster autonomy support (AS). Groups met weekly for 6 months with assessments at 0, 3, 6, and 12 months.

RESULTS

Percent weight loss at 6 and 12 months was 10.4% ± 6.5% and 9.2% ± 8.2%. No differences were observed between the BWL and SDT-WL conditions in percent weight loss or changes in AS. Across conditions, higher baseline AS predicted greater weight loss at 6 and 12 months (ps <.001). Increases in AS over time predicted greater weight loss at 6 and 12 months (ps ≤ .02). Post hoc moderation analysis indicated that only participants with low (but not high) baseline AS achieved greater gains in AS at 12 months in SDT-WL than in the BWL conditions (p < .02).

CONCLUSIONS

Although no differences were found between conditions on weight loss or changes in autonomy support behavior, autonomy support from one's spouse predicted weight loss in both couples-based weight-loss approaches. For couples with low levels of AS, an SDT-informed approach was effective at increasing this desirable interpersonal behavior. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

The Microbiota-Gut-Brain Axis

The importance of the gut-brain axis in maintaining homeostasis has long been appreciated. However, the past 15 yr have seen the emergence of the microbiota (the trillions of microorganisms within and on our bodies) as one of the key regulators of gut-brain function and has led to the appreciation of the importance of a distinct microbiota-gut-brain axis. This axis is gaining ever more traction in fields investigating the biological and physiological basis of psychiatric, neurodevelopmental, age-related, and neurodegenerative disorders. The microbiota and the brain communicate with each other via various routes including the immune system, tryptophan metabolism, the vagus nerve and the enteric nervous system, involving microbial metabolites such as short-chain fatty acids, branched chain amino acids, and peptidoglycans. Many factors can influence microbiota composition in early life, including infection, mode of birth delivery, use of antibiotic medications, the nature of nutritional provision, environmental stressors, and host genetics. At the other extreme of life, microbial diversity diminishes with aging. Stress, in particular, can significantly impact the microbiota-gut-brain axis at all stages of life. Much recent work has implicated the gut microbiota in many conditions including autism, anxiety, obesity, schizophrenia, Parkinson’s disease, and Alzheimer’s disease. Animal models have been paramount in linking the regulation of fundamental neural processes, such as neurogenesis and myelination, to microbiome activation of microglia. Moreover, translational human studies are ongoing and will greatly enhance the field. Future studies will focus on understanding the mechanisms underlying the microbiota-gut-brain axis and attempt to elucidate microbial-based intervention and therapeutic strategies for neuropsychiatric disorders.

Perceived Barriers in the Decision for Bariatric and Metabolic Surgery: Results from a Representative Study in Germany

BACKGROUND

Attitudes of the general public may be an influencing factor for low surgery rates: When skepticism is high, support for individuals wanting or needing to undergo surgery may diminish. This study assesses the relevance of barriers to metabolic surgery.

METHODS

The study was conducted using a representative sample of the German population (n = 1007). Participants were asked to imagine that they would have to decide for or against metabolic surgery and rate how this decision would be influenced by a number of reasons given to them (Likert scale). Results are presented by weight status.

RESULTS

The barrier found most irrelevant is that surgery could be considered cheating across all weight groups. About a fourth of the sample state that not knowing enough about surgery (28.5%), being afraid of surgery (28.3%), and potential negative consequences after surgery (24.5%) are reasons against metabolic surgery that were rated extremely relevant. Having obesity was a significant predictor of endorsement in two variables: feeling like cheating (lower probability for relevance, OR = 0.58, p = 0.025) and a lack of knowledge (lower probability for relevance, OR = 0.59, p = 0.031).

CONCLUSIONS

In summary, the public's view of weight loss surgery lacks information about post-surgical consequences. It is important to address these points in the public and in social networks of patients as they may be pre- or antecedent of surgery stigma.

The Role of Collective Efficacy in Reducing Health Disparities: A Systematic Review

Many improvements in health equity are spearheaded by community collaborations working to change policy and social norms. But how can collective efficacy (CE), defined as the willingness and ability of a group to work toward a common good, be increased? Eight articles reporting on interventions aiming to reduce health disparities by improving CE were found for this systematic literature review. All studies showed improvements in CE and most found reduction in disparities, but operationalization of CE varied. Findings support a model of how CE can address health disparities, which can guide standardization of CE interventions and measures.

Food Insecurity and Obesity: Exploring the Role of Social Support

BACKGROUND

Women are disproportionately affected by both obesity and food insecurity. Food insecurity occurs when there is limited ability to acquire adequate foods. It is unknown whether social support can reduce the effect of food insecurity on increased obesity. This study seeks to determine whether social support modifies the relationship between food insecurity and obesity.

METHODS

We conducted a cross-sectional study in a nationally representative sample of 4672 women aged ≥40 years using National Health and Nutrition Examination Survey (2003-2008). Individual food insecurity was assessed based on the U.S. Department of Agriculture 18-item validated household food security scale. Women were categorized as fully food secure (0 affirmative responses) or food insecure (1-10 affirmative responses). Obesity was defined as body mass index ≥30 kg/m². Outcomes were analyzed by multivariable logistic regression.

RESULTS

Fourteen percent were food insecure. Women with food insecurity had 1.4 the odds of obesity as those who were fully food secure, adjusting for race/ethnicity and health status (95% confidence interval [CI] 1.22-1.62). Food-insecure women were 80% less likely to report strong social support than women who were fully food secure (95% CI 0.11-0.36). Social support as measured in this study did not modify the association between food insecurity and obesity.

CONCLUSIONS

Women reporting food insecurity reported lower levels of social support and were more likely to experience obesity. Interventions to reduce obesity in women who are food insecure must consider the limited resources available to these women.

An innovative team-based weightloss competition to reduce cardiovascular and diabetes risk among Māori and Pacific people: rationale and method for the study and its evaluation

Background

Obesity rates for New Zealand (NZ) Pacific and Māori (NZ indigenous people) are among the highest in the world. Long-term results of weight management programmes for adults have been modest but primarily focused on individuals. This paper describes the rationale and methodology for a trial of a culturally tailored team-based weightloss competition conducted online with community level support.

Methods/Design

A quasi-experimental design was used to compare an intervention and control group. Three six-month competitions with seven teams of seven Māori or Pacific people (N = 147) were run. Eligible participants were: Māori or Pacific, 16 years of age and above, obese (BMI ≥30 kg/m²) and either at risk of or already diagnosed with type 2 diabetes (HbA1c >50 mmol/mol) or cardiovascular disease.

The intervention facilitated group use of an internet-based competition offering financial incentives, education and support. The primary outcome was percentage of individual weight lost at 12-months. Secondary outcomes were percentage reduced total cholesterol and glycated haemoglobin (HbA1c). Data collected at baseline, 6-months and 12-months included: height, body weight, blood lipids and HbA1c, eating and dieting habits, family support, food access, alcohol use, nutrition literacy, activity levels, perceptions of weight, stress and sleep, and, perceived contagion effect. Process evaluation tasks will inform acceptability.

Discussion

An attractive, easy to understand weight change programme that effectively reduces disease risk among Māori and Pacific is desperately needed. Web-based delivered support and information to largely self-directed teams could also ease exponential rises in costs to the health system.

Trial registration

Trial Id: ACTRN12617000871347.

Project TEAMS (Talking about Eating, Activity, and Mutual Support): a randomized controlled trial of a theory-based weight loss program for couples

BACKGROUND

Obesity risk is shared between spouses, yet existing weight loss programs focus on individuals and not the marital dyad. Given the interdependence of weight in couples, weight management outcomes might be improved by targeting joint weight loss and the creation of an interpersonal milieu that supports long-term behavior change. According to Self-Determination Theory (SDT), greater autonomous self-regulation of behaviors, and subsequently better treatment outcomes, are observed in needs supportive environments in which personally meaningful choice is supported and criticism and control are minimized. Correlational analyses confirm these pathways in weight management, with needs support from one's spouse or partner emerging as a distinct predictor of weight loss success. Research is now needed to establish causal links and to develop and test weight loss interventions designed to facilitate the needs supportive behavior of spouses.

METHODS

Project TEAMS (Talking about Eating, Activity, and Mutual Support) is a randomized controlled trial testing a couples-based intervention, grounded in SDT, designed to change the social context of weight loss by training spouses to provide needs support for each other's eating and physical activity behavior. Sixty-four couples will be randomized to either 6 months of behavioral weight loss treatment informed by SDT (SDT-WL) or to 6 months of standard behavioral weight loss treatment (BWL). Couples will attend weekly sessions for 6 months and will be assessed at 0, 3, 6, and 12 months. By bolstering needs support, SDT-WL is predicted to increase autonomous self-regulation and perceived competence and produce greater weight loss and maintenance than standard behavioral treatment. Exploratory analyses will examine the SDT process model prediction that the influence of needs support on treatment outcomes will be mediated by autonomous self-regulation and perceived competence.

DISCUSSION

This study addresses the fundamental importance of interpersonal support in weight management by focusing on couples rather than individuals and using a rich theoretical framework to train spouses in supportive behaviors.

TRIAL REGISTRATION

Clinicaltrials.gov ; NCT02570009 .

The association between social cohesion in the neighborhood and body mass index (BMI): An examination of gendered differences among urban-dwelling Canadians

Overweight and obesity are major global public health concerns. Obesity is multifactorial in origin and influenced by genetics, psychosocial factors, eating and physical activity behaviors, as well as the environment. The objective of this study is to examine the impact of social cohesion on gender differences in body mass index (BMI) for urban-dwelling Canadians. Cross-sectional data were used from the Neighborhood Effects on Health and Well-being Study (NEHW) in Toronto, Canada (n=2300). Our main outcome, BMI, was calculated from self-reported height and weight (weight (kg)/height (m)²). Using multi-level logistic regression models, we identified a significant interaction between social cohesion and gender on being overweight/obese. Women with higher social cohesion had slightly lower odds of being overweight/obese (OR: 0.96, 95%CI: 0.94 to 0.99) compared to men, after adjusting for other sociodemographic factors (e.g., age, income, education), and neighborhood characteristics (e.g., walkability, neighborhood safety and material deprivation). Future public health research and interventions should consider the differential mechanisms involved in overweight/obesity by gender. The exact mechanisms behind how the social environment influences these pathways are still unclear and require future research.

Applying and advancing behavior change theories and techniques in the context of a digital health revolution: proposals for more effectively realizing untapped potential

As more behavioral health interventions move from traditional to digital platforms, the application of evidence-based theories and techniques may be doubly advantageous. First, it can expedite digital health intervention development, improving efficacy, and increasing reach. Second, moving behavioral health interventions to digital platforms presents researchers with novel (potentially paradigm shifting) opportunities for advancing theories and techniques. In particular, the potential for technology to revolutionize theory refinement is made possible by leveraging the proliferation of "real-time" objective measurement and "big data" commonly generated and stored by digital platforms. Much more could be done to realize this potential. This paper offers proposals for better leveraging the potential advantages of digital health platforms, and reviews three of the cutting edge methods for doing so: optimization designs, dynamic systems modeling, and social network analysis.

Designing and Undertaking a Health Economics Study of Digital Health Interventions

This paper introduces and discusses key issues in the economic evaluation of digital health interventions. The purpose is to stimulate debate so that existing economic techniques may be refined or new methods developed. The paper does not seek to provide definitive guidance on appropriate methods of economic analysis for digital health interventions. This paper describes existing guides and analytic frameworks that have been suggested for the economic evaluation of healthcare interventions. Using selected examples of digital health interventions, it assesses how well existing guides and frameworks align to digital health interventions. It shows that digital health interventions may be best characterized as complex interventions in complex systems. Key features of complexity relate to intervention complexity, outcome complexity, and causal pathway complexity, with much of this driven by iterative intervention development over time and uncertainty regarding likely reach of the interventions among the relevant population. These characteristics imply that more-complex methods of economic evaluation are likely to be better able to capture fully the impact of the intervention on costs and benefits over the appropriate time horizon. This complexity includes wider measurement of costs and benefits, and a modeling framework that is able to capture dynamic interactions among the intervention, the population of interest, and the environment. The authors recommend that future research should develop and apply more-flexible modeling techniques to allow better prediction of the interdependency between interventions and important environmental influences.

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.

Neighbourhood social capital: measurement issues and associations with health outcomes

We compared ecometric neighbourhood scores of social capital (contextual variation) to mean neighbourhood scores (individual and contextual variation), using several health-related outcomes (i.e. self-rated health, weight status and obesity-related behaviours). Data were analysed from 5,900 participants in the European SPOTLIGHT survey. Factor analysis of the 13-item social capital scale revealed two social capital constructs: social networks and social cohesion. The associations of ecometric and mean neighbourhood-level scores of these constructs with self-rated health, weight status and obesity-related behaviours were analysed using multilevel regression analyses, adjusted for key covariates. Analyses using ecometric and mean neighbourhood scores, but not mean neighbourhood scores adjusted for individual scores, yielded similar regression coefficients. Higher levels of social network and social cohesion were not only associated with better self-rated health, lower odds of obesity and higher fruit consumption, but also with prolonged sitting and less transport-related physical activity. Only associations with transport-related physical activity and sedentary behaviours were associated with mean neighbourhood scores adjusted for individual scores. As analyses using ecometric scores generated the same results as using mean neighbourhood scores, but different results when using mean neighbourhood scores adjusted for individual scores, this suggests that the theoretical advantage of the ecometric approach (i.e. teasing out individual and contextual variation) may not be achieved in practice. The different operationalisations of social network and social cohesion were associated with several health outcomes, but the constructs that appeared to represent the contextual variation best were only associated with two of the outcomes.

Psychosocial environment: definitions, measures and associations with weight status--a systematic review

Socio-ecological models suggest that many elements of the social environment act as upstream determinants of obesity. This systematic review examined definitions, measures and strength of associations between the psychosocial environment and adult weight status. Studies were included if they were conducted on adults, the outcome was weight status, carried out in any developed country and investigated at least one psychosocial environmental construct. Six databases for primary studies were searched: EMBASE, MEDLINE, PsycINFO, Scopus, Web of Science and the Cochrane Library. We restricted our search to studies published in English between January 1995 and February 2015. An adapted 'Quality Assessment Tool for Quantitative Studies' was used to evaluate risk of bias of included studies. Out of 14,784 screened records, 42 articles were assessed using full text. A total of 19 studies were included. The strongest associations with weight status were found for social capital and collective efficacy, although few studies found significant associations. There was heterogeneity in the definitions and metrics of psychosocial environmental constructs. There is limited evidence that greater social capital and collective efficacy are associated with healthier weight status. The research conducted to date has not robustly identified relations. We highlight challenges to undertaking research and establishing causality in this field and provide recommendations for further research.

The Epidemiology of Obesity: A Big Picture

The epidemic of overweight and obesity presents a major challenge to chronic disease prevention and health across the life course around the world. Fueled by economic growth, industrialization, mechanized transport, urbanization, an increasingly sedentary lifestyle, and a nutritional transition to processed foods and high-calorie diets over the last 30 years, many countries have witnessed the prevalence of obesity in its citizens double and even quadruple. A rising prevalence of childhood obesity, in particular, forebodes a staggering burden of disease in individuals and healthcare systems in the decades to come. A complex, multifactorial disease, with genetic, behavioral, socioeconomic, and environmental origins, obesity raises the risk of debilitating morbidity and mortality. Relying primarily on epidemiologic evidence published within the last decade, this non-exhaustive review discusses the extent of the obesity epidemic, its risk factors-known and novel-, sequelae, and economic impact across the globe.

Weight stigma "gets under the skin"-evidence for an adapted psychological mediation framework: a systematic review

OBJECTIVE

Research consistently shows a negative view of individuals with obesity in the general public and in various other settings. Stigma and discrimination can be considered chronic stressors, as these factors have a profound impact on the psychological well-being of the affected individuals. This article proposes a framework that entails a mediation of the adverse effects of discrimination and stigmatization on mental well-being through elevated psychological risk factors that are not unique to weight but that could affect overweight and normal-weight individuals alike.

METHODS

A systematic review was conducted to assess the prevalence of psychological risk factors, such as self-esteem and coping, in individuals with obesity.

RESULTS

Forty-six articles were assessed and included for detailed analysis. The number of studies on these topics is limited to certain dimensions of psychological processes. The best evaluated association of obesity and psychosocial aspects is seen for self-esteem. Most studies establish a negative association of weight and self-esteem in children and adults. All studies with mediation analysis find a positive mediation through psychological risk factors on mental health outcomes.

CONCLUSIONS

This review shows that elevated psychological risk factors are existent in individuals with obesity and that they may be a mediator between weight discrimination and pathopsychological outcomes.

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.

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

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

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