Marriage and parenthood in relation to obesogenic neighborhood trajectories: The CARDIA study

Food insecurity among African Americans in the United States: A scoping review

In 2019, the estimated prevalence of food insecurity for Black non-Hispanic households was higher than the national average due to health disparities exacerbated by forms of racial discrimination. During the COVID-19 pandemic, Black households have experienced higher rates of food insecurity when compared to other populations in the United States. The primary objectives of this review were to identify which risk factors have been investigated for an association with food insecurity, describe how food insecurity is measured across studies that have evaluated this outcome among African Americans, and determine which dimensions of food security (food accessibility, availability, and utilization) are captured by risk factors studied by authors. Food insecurity related studies were identified through a search of Google Scholar, PubMed, CINAHL Plus, MEDLINE®, PsycINFO, Health Source: Nursing/Academic Edition, and Web of Science™ (Clarivate), on May 20, 2021. Eligible studies were primary research studies, with a concurrent comparison group, published in English between 1995 and 2021. Ninety-eight relevant studies were included for data charting with 37 unique measurement tools, 115 risk factors, and 93 possible consequences of food insecurity identified. Few studies examined factors linked to racial discrimination, behaviour, or risk factors that mapped to the food availability dimension of food security. Infrequently studied factors, such as lifetime racial discrimination, socioeconomic status (SES), and income insecurity need further investigation while frequently studied factors such as age, education, race/ethnicity, and gender need to be summarized using a systematic review approach so that risk factor impact can be better assessed. Risk factors linked to racial discrimination and food insecurity need to be better understood in order to minimize health disparities among African American adults during the COVID-19 pandemic and beyond.

Understanding the Heterogeneity of Obesity and the Relationship to the Brain-Gut Axis

Obesity is best understood as a multifactorial metabolic imbalances disorder. In a cross-sectional study, we aimed to explore sociodemographic and dietary determinants of obesity in relation to brain-gut homeostasis among overweight and obese individuals. Multivariate logistic regression models were used to examine obesity and its association with sociodemographic and dietary factors. Biological variables examined included the gut microbiome, fecal amino acid metabolites and brain structural volumes. Among 130 participants, there were higher odds of obesity if individuals were Hispanic (adjusted odds ratio (aOR) 1.56, p = 0.014). Compared to non-Hispanics, Hispanics differed in gut microbial composition (p = 0.046) with lower microbial species richness (Chao1) (p = 0.032) and evenness (Shannon) (p = 0.0029). Fourteen of the twenty fecal amino acids including branch-chain- and aromatic- amino acids were increased among Hispanics (q < 0.05). Brain structural volumes in reward regions were decreased in Hispanics (pallidum, q = 0.036; brainstem, q = 0.011). Correlation patterns suggest complex brain-gut interactions differ by Hispanic ethnicity. In conclusion, Hispanics expressed a unique brain-gut microbial signature, which was associated with obesity despite sociodemographic and dietary differences. Addressing ethnic disparities guided by biologic phenotypes may unlock novel understanding of obesity heterogeneity and treatment strategies.

Associations of early adulthood life transitions with changes in fast food intake: a latent trajectory analysis

BACKGROUND

Early adulthood is a period of rapid personal development when individuals experience major life transitions (e.g. leaving the parental home, leaving education, beginning employment, cohabitation and parenthood). Changes in social and physical environments associated with these transitions may influence development of health-related behaviours. Consumption of fast food is one behaviour associated with poor diet and long-term health outcomes. In this study we assess how frequency of fast food consumption changes across early adulthood, and how major life transitions are associated with changes in fast food intake.

METHODS

Data were collected across four waves of the Project EAT study, from mean age 14.9 (SD = 1.6) to mean age 31.1 (SD = 1.6) years. Participants reporting data at two or more waves were included (n = 2902). Participants reported past week frequency of eating food from a fast food restaurant and responded to questions on living arrangements, education and employment participation, and having children. To assess changes in fast food we developed a latent growth model incorporating an underlying trajectory of fast food intake, five life transitions, and time-invariant covariates.

RESULTS

Mean fast food intake followed an underlying quadratic trajectory, increasing through adolescence to a maximum of 1.88 (SE 0.94) times/week and then decreasing again through early adulthood to 0.76 (SE 2.06) times/week at wave 4. Beginning full-time employment and becoming a parent both contributed to increases in fast food intake, each resulting in an average increase in weekly fast food intake of 0.16 (p < 0.01) times/week. Analysis of changes between pairs of waves revealed stronger associations for these two transitions between waves 1-2 (mean age 14.9-19.4 years) than seen in later waves. Leaving the parental home and beginning cohabitation were associated with decreases in fast food intake of - 0.17 (p = 0.004) and - 0.16 (p = 0.007) times/week respectively, while leaving full-time education was not associated with any change.

CONCLUSIONS

The transitions of beginning full-time employment and becoming a parent were associated with increases in fast food intake. Public health policy or interventions designed to reduce fast food intake in young adults may benefit from particular focus on populations experiencing these transitions, to ameliorate their impact.

Maternal prepregnancy BMI and size at birth: race/ethnicity-stratified, within-family associations in over 500,000 siblings

PURPOSE

To estimate racial/ethnic-stratified effects of maternal prepregnancy BMI on size for gestational age at birth, by comparing siblings within families.

METHODS

This study examined linked vital statistics and patient discharge data from 580,960 infants born to 278,770 women in the State of California (2007-2012). To control for family-level confounding, we used fixed effects multinomial regression, modeling size for gestational age (small [SGA], appropriate, large [LGA]) as a function of maternal BMI (underweight, normal weight, overweight, obesity class I, II, III) and time-varying covariates. We conducted overall and race/ethnicity-stratified (non-Hispanic white, black, Asian; Hispanic) analyses. For comparison, we fit analogous random effects models, which do not control for family-level confounding.

RESULTS

In fixed effects models, maternal BMI was most strongly associated with LGA in non-Hispanic white women, reaching 6.7 times greater for class III obesity (OR [95% CI]: 6.7 [5.1, 8.7]); and weakest in black women (OR [95% CI]: 3.0 [1.5, 5.7]). Associations with SGA were similar across race/ethnicity. Compared with random effects estimates, fixed effects were most attenuated for LGA associations among racial/ethnic minority women.

CONCLUSIONS

Maternal prepregnancy BMI was differentially associated with size for gestational age across racial/ethnic groups, with the strongest family-level confounding in racial/ethnic minority women.

Associations between family factors and body weight gain from 20 years old

BACKGROUND

Although family factors can greatly impact adult health, little is known about the extent to which family factors are related to body weight gain (BWG) in adulthood. This study aimed to examine the associations between family factors and BWG from 20 years old.

METHODS

Among the 6395 possible participants aged 35 to 79 years, 2884 men and 2171 women were eligible for the study. Present body mass indexes (BMI) were measured, and family factors and body weight from 20 years old (i.e., BMI_20yr) were collected using a self-administered questionnaire. The differences between BMI and BMI_20yr were calculated, and those with increases of BMI ≥2.5 kg/m² (i.e., ≥7.5 and 6.0 kg in men and women, respectively) were defined as 'cases' of BWG. Using a multiple logistic regression analysis, the odds ratios (ORs, 95% confidence intervals [CIs] and p for trend) were estimated.

RESULTS

In the men, no association was found. In the women, the ORs were 0.31, 1.00 and 0.77 (0.17-0.58, [reference], and (0.52-1.29), p < 0.001) as per their marital status: unmarried, married, and bereaved/divorced, respectively. Although no association was found with family structure (i.e., single, couple, and two and three generations living together), for familial relationships, the ORs were 1.00, 1.11 and 1.86 ([reference], 0.85-1.46, and 1.25-2.79, p < 0.01) for 'good', 'somewhat good', and 'not so good/not good', respectively. Even if a 'case' of BWG was ≥3.5 kg/m², nearly the same risks remained.

CONCLUSION

Marital status and family relationships were associated with decreased and increased risks of BWG only in the female participants. Family factors should be considered when advising women on body weight control.

Does unmeasured confounding influence associations between the retail food environment and body mass index over time? The Coronary Artery Risk Development in Young Adults (CARDIA) study

Background

Findings in the observational retail food environment and obesity literature are inconsistent, potentially due to a lack of adjustment for residual confounding.

Methods

Using data from the CARDIA study (n = 12 174 person-observations; 6 examinations; 1985-2011) across four US cities (Birmingham, AL; Chicago, IL; Minneapolis, MN; Oakland, CA), we used instrumental-variables (IV) regression to obtain causal estimates of the longitudinal associations between the percentage of neighbourhood food stores or restaurants (per total food outlets within 1 km network distance of respondent residence) with body mass index (BMI), adjusting for individual-level socio-demographics, health behaviours, city, year, total food outlets and market-level prices. To determine the presence and extent of bias, we compared the magnitude and direction of results with ordinary least squares (OLS) and random effects (RE) regression, which do not control for residual confounding, and with fixed effects (FE) regression, which does not control for time-varying residual confounding.

Results

Relative to neighbourhood supermarkets (which tend to be larger and have healthier options than grocery stores), a higher percentage of grocery stores [mean = 53.4%; standard deviation (SD) = 31.8%] was positively associated with BMI [β = 0.05; 95% confidence interval (CI) = 0.01, 0.10] using IV regression. However, associations were negligible or null using OLS (β = -0.001; 95% CI = -0.01, 0.01), RE (β = -0.003; 95% CI = -0.01, 0.0001) and FE (β = -0.003; 95% CI = -0.01, 0.0002) regression. Neighbourhood convenience stores and fast-food restaurants were not associated with BMI in any model.

Conclusions

Longitudinal associations between neighbourhood food outlets and BMI were greater in magnitude using a causal model, suggesting that weak findings in the literature may be due to residual confounding.

Use of formative research and social network theory to develop a group walking intervention: Sumter County on the Move!

Although social support is a frequently cited enabler of physical activity, few studies have examined how to harness social support in interventions. This paper describes community-based formative research to design a walking program for mobilizing naturally occurring social networks to support increases in walking behavior. Focus group methods were used to engage community members in discussions about desired walking program features. The research was conducted with underserved communities in Sumter County, South Carolina. The majority of focus group participants were women (76%) and African American (92%). Several important themes emerged from the focus group results regarding attitudes toward walking, facilitators of and barriers to walking, ideal walking program characteristics, and strategies for encouraging community members to walk. Most noteably, the role of existing social networks as a supportive influence on physical activity was a recurring theme in our formative research and a gap in the existing evidence base. The resulting walking program focused on strategies for mobilizing, supporting and reinforcing existing social networks as mechanisms for increasing walking. Our approach to linking theory, empirical evidence and community-based formative research for the development of a walking intervention offers an example for practitioners developing intervention strategies for a wide range of behaviors.