Spatial mobility and environmental effects on obesity

How socioeconomic status affects weight status through health-related lifestyles: a latent class analysis

AIMS

Obesity levels have increased worldwide with serious public health concerns. However, weight status is related to socioeconomic status (SES), which may also influence health-related lifestyles. Here, we study the association between SES and obesity mediated by diet and physical activity.

METHODS AND RESULTS

Using cross-sectional data from 2006, 2011, 2014, and 2017 Spanish health surveys (the final sample consisted of 61 768 adults aged between 18 and 64 years), we conducted a latent class analysis to estimate health-related lifestyle clusters (based on dietary patterns and physical activity) and mediation analyses to evaluate the association of SES and obesity through the clustering of health-related lifestyles. In both men and women, SES was inversely related to obesity (P < 0.001) and positively related to healthier lifestyle classes (P < 0.001). Obesity was inversely related to healthier lifestyle classes (P < 0.001). A small-although significant-proportion mediated by the clustering of lifestyles was found as follows: 4.9%, 95% CI (6.6%, 3.2%) in men and 2.3%, 95% CI (3.4%, 1.3%) in women for educational attainment, 5.3%, 95% CI (7.2%, 3.6%) in men and 2.0%, 95% CI (2.9%, 1.1%) in women for occupational social class, and 4.9%, 95% CI (6.5%, 3.1%) and 1.9%, 95% CI (2.9%, 1.1%) combining the above two SES indicators.

CONCLUSIONS

SES is related to obesity through clustering health-related lifestyles, with greater emphasis on men. However, the complex relationship between SES and weight status also suggests other indicators that contribute to the social gradient of obesity.

Heterogeneity in place effects on health: The case of time preferences and adolescent obesity

We leverage a natural experiment in combination with data on adolescents' time preferences to assess whether there is heterogeneity in place effects on adolescent obesity. We exploit the plausibly exogenous assignment of military servicemembers, and consequently their children, to different installations to identify place effects. Adolescents' time preferences are measured by a validated survey scale. Using the obesity rate in the assigned installation county as a summary measure of its obesity-related environments, we show that exposure to counties with higher obesity rates increases the likelihood of obesity among less patient adolescents but not among their more patient counterparts.

Childhood obesity, is fast food exposure a factor?

Access to fast food has often been blamed for the rise in obesity which in turn has motivated policies to curb the spread of fast food. However, robust evidence in this area is scarce, particularly using data outside of the US. It is difficult to estimate a causal effect of fast food given spatial sorting and ever-present exposure. We investigate whether the residential access to fast food increased BMI of adolescents at a time when fast food restaurants started to open in the UK. The time period presents the study with large spatial and temporal differences in exposure as well as plausibly exogenous variation. We merge data on the location and timing of the first openings of all fast food outlets in the UK from 1968-1986, with data on objectively measured BMI from the 1970 British Cohort Survey. The relationship between adolescent BMI and the distance from the respondents' homes and time since opening, is studied using OLS and Instrumental Variables regression. We find that fast food exposure had no effect on BMI. Extensive robustness checks do not change our conclusion.

The impact of the consumer and neighbourhood food environment on dietary intake and obesity-related outcomes: A systematic review of causal impact studies

BACKGROUND

The food environment has been found to impact population dietary behaviour. Our study aimed to systematically review the impact of different elements of the food environment on dietary intake and obesity.

METHODS

We searched MEDLINE, Embase, PsychInfo, EconLit databases to identify literature that assessed the relationship between the built food environments (intervention) and dietary intake and obesity (outcomes), published between database inception to March 26, 2020. All human studies were eligible except for those on clinical sub-groups. Only studies with causal inference methods were assessed. Studies focusing on the food environment inside homes, workplaces and schools were excluded. A risk of bias assessment was conducted using the CASP appraisal checklist. Findings were summarized using a narrative synthesis approach.

FINDINGS

58 papers were included, 55 of which were conducted in high-income countries. 70% of papers focused on the consumer food environments and found that in-kind/financial incentives, healthy food saliency, and health primes, but not calorie menu labelling significantly improved dietary quality of children and adults, while BMI results were null. 30% of the papers focused on the neighbourhood food environments and found that the number of and distance to unhealthy food outlets increased the likelihood of fast-food consumption and higher BMI for children of any SES; among adults only selected groups were impacted - females, black, and Hispanics living in low and medium density areas. The availability and distance to healthy food outlets significantly improved children's dietary intake and BMI but null results were found for adults.

INTERPRETATION

Evidence suggests certain elements of the consumer and neighbourhood food environments could improve populations dietary intake, while effect on BMI was observed among children and selected adult populations. Underprivileged groups are most likely to experience and impact on BMI. Future research should investigate whether findings translate in other countries.

Do peer social relationships mediate the harmful effects of a housing mobility experiment on boys' risky behaviors?

PURPOSE

The purpose of this study was to understand why a housing mobility experiment caused harmful effects on adolescent boys' risky behaviors.

METHODS

Moving to Opportunity (MTO) (1994-2010) randomly assigned volunteer families to a treatment group receiving a Section 8 rental voucher or a public housing control group. Our outcome was a global risky behavior index (RBI; measured in 2002, n = 750 boys) measuring the fraction of 10 items the youth engaged in, 6 measuring past 30-day substance use and 4 measuring recent risky sexual behavior. Potential mediators (measured in 2002) included peer social relationships (e.g., peer drug use, peer gang membership).

RESULTS

The voucher treatment main effect on boys' RBI was harmful (B (SE) = 0.05 (0.02), 95% CI 0.01, 0.08), and treatment marginally increased having friends who used drugs compared to controls (B (SE) = 0.67 (0.23), 95% CI 0.22, 1.12). Having friends who used drugs marginally mediated the MTO treatment effect on RBI (indirect effect: B (SE) = 0.02(.01), 95% CI -0.002, 0.04), reducing the total treatment effect by 39%.

CONCLUSIONS

Incorporating additional supports into housing voucher programs may help support teenage boys who experience disruptions to their social networks, to buffer potential adverse consequences of residential mobility.

Neighbourhood effects on obesity: scoping review of time-varying outcomes and exposures in longitudinal designs

CONTEXT AND OBJECTIVES

Neighbourhood effect research on obesity took off in the early 2000s and was composed of mostly cross-sectional observational studies interested in various characteristics of the built environment and the socioeconomic environment. To limit biases related to self-selection and life course exposures, many researchers apply longitudinal designs in their studies. Until now, no review has specifically and exclusively examined longitudinal studies and the specific designs of these studies. In this review, we intend to answer the following research question: how are the temporal measurements of contextual exposure and obesity outcomes integrated into longitudinal studies that explore how neighbourhood-level built and socioeconomic environments impact adult obesity?

DESIGN

A systematic search strategy was designed to address the research question. The search was performed in Embase, Web of Science and PubMed, targeting scientific papers published before 1 January 2018. The eligible studies reported results on adults, included exposure that was limited to neighbourhood characteristics at the submunicipal level, included an outcome limited to obesity proxies, and reported a design with at least two exposure measurements or two outcome measurements.

RESULTS

This scoping review identified 66 studies that fit the eligibility criteria. A wide variety of neighbourhood characteristics were also measured, making it difficult to draw general conclusions about associations between neighbourhood exposure and obesity. We applied a typology that classified studies by whether exposure and outcome were measured as varying or fixed. Using this typology, we found that 32 studies reported both neighbourhood exposure and obesity outcomes that were varying in time; 28 reported varying outcomes but fixed exposures; and 6 had fixed outcomes and varying exposures.

CONCLUSION

Our typology illustrates the variety of longitudinal designs that were used in the selected studies. In the light of our results, we make recommendations on how to better report longitudinal designs and facilitate comparisons between studies.

Built Environment Exposures of Adults in the Moving to Opportunity Experiment

This paper describes environmental exposures of adult participants in the Moving to Opportunity for Fair Housing (MTO) experiment over a four to seven year period from baseline to the interim evaluation. The MTO experiment randomized participants living in public housing or private assisted housing at baseline into experimental and control groups and provided a housing voucher for experimental group participants to move to neighborhoods with less than 10 percent of the population below the poverty line. However, few studies have examined how this move affected exposures to health promoting environments. We used data on residential locations of MTO participants and archival data on the built and food environment to construct environmental exposure variables. MTO participants in the experimental and Section 8 groups lived in neighborhoods with higher food prices, less high intensity development and more open space relative to the control group. The findings suggest that housing policies can have potential health consequences by altering health-related environmental exposures.

A systematic review employing the GeoFERN framework to examine methods, reporting quality and associations between the retail food environment and obesity

This systematic review quantifies methods used to measure the 'retail food environment' (RFE), appraises the quality of methodological reporting, and examines associations with obesity, accounting for differences in methods. Only spatial measures of the RFE, such as food outlet proximity were included. Across the 113 included studies, methods for measuring the RFE were extremely diverse, yet reporting of methods was poor (average reporting quality score: 58.6%). Null associations dominated across all measurement methods, comprising 76.0% of 1937 associations in total. Outcomes varied across measurement methods (e.g. narrow definitions of 'supermarket': 20.7% negative associations vs 1.7% positive; broad definitions of 'supermarket': 9.0% negative associations vs 10.4% positive). Researchers should report methods more clearly, and should articulate findings in the context of the measurement methods employed.

Geographic determinants of individual obesity risk in Spain: A multilevel approach

This paper seeks to understand the determinants of individual body weight status and obesity risk in Spain by concurrently examining individual and regional characteristics. The data are drawn from the National Health Survey of Spain for the year 2011-2012 (INE-National Statistical Institute of Spain) and contain information for a representative sample of 12,671 adults across 50 provinces in Spain. A multilevel analysis is carried out to examine the determinants of individual weight status and obesity, controlling not only for the individual effects and those of the immediate environment but also for the broader setting to which individuals and their immediate environment belong. Our findings suggest that attributes from all three levels of analysis have an effect on individual weight status and obesity. Lack of green spaces and criminality taken as proxies of the social environment positively affect individual and women's BMI and obesity, respectively.

Measures of the food environment: A systematic review of the field, 2007-2015

BACKGROUND

Many studies have examined the relationship between the food environment and health-related outcomes, but fewer consider the integrity of measures used to assess the food environment. The present review builds on and makes comparisons with a previous review examining food environment measures and expands the previous review to include a more in depth examination of reliability and validity of measures and study designs employed.

METHODS

We conducted a systematic review of studies measuring the food environment published between 2007 and 2015. We identified these articles through: PubMed, Embase, Web of Science, PsycINFO, and Global Health databases; tables of contents of relevant journals; and the National Cancer Institute's Measures of the Food Environment website. This search yielded 11,928 citations. We retained and abstracted data from 432 studies.

RESULTS

The most common methodology used to study the food environment was geographic analysis (65% of articles) and the domination of this methodology has persisted since the last review. Only 25.9% of studies in this review reported the reliability of measures and 28.2% reported validity, but this was an improvement as compared to the earlier review. Very few of the studies reported construct validity. Studies reporting measures of the school or worksite environment have decreased since the previous review. Only 13.9% of the studies used a longitudinal design.

CONCLUSIONS

To strengthen research examining the relationship between the food environment and population health, there is a need for robust and psychometrically-sound measures and more sophisticated study designs.

Advancing research on racial-ethnic health disparities: improving measurement equivalence in studies with diverse samples

To conduct meaningful, epidemiologic research on racial-ethnic health disparities, racial-ethnic samples must be rendered equivalent on other social status and contextual variables via statistical controls of those extraneous factors. The racial-ethnic groups must also be equally familiar with and have similar responses to the methods and measures used to collect health data, must have equal opportunity to participate in the research, and must be equally representative of their respective populations. In the absence of such measurement equivalence, studies of racial-ethnic health disparities are confounded by a plethora of unmeasured, uncontrolled correlates of race-ethnicity. Those correlates render the samples, methods, and measures incomparable across racial-ethnic groups, and diminish the ability to attribute health differences discovered to race-ethnicity vs. to its correlates. This paper reviews the non-equivalent yet normative samples, methodologies and measures used in epidemiologic studies of racial-ethnic health disparities, and provides concrete suggestions for improving sample, method, and scalar measurement equivalence.