Tabashir Z. Nobari

Immigrant enclaves and obesity in preschool-aged children in Los Angeles County.

While neighborhood environments are increasingly recognized as important contributors to obesity risk, less has been reported on the socio-cultural aspects of neighborhoods that influence obesity development. This is especially true among immigrants, who may lack the necessary language skills to navigate their new living environments. In this study, we tested the hypothesis that young children of immigrants would be at lower obesity risk if they lived in neighborhoods where neighbors share the same language and culture. Using 2000 Census data and 2003-2009 data from the Special Supplemental Nutrition Program for Women, Infants and Children in Los Angeles County, we examined the relation between BMI z-scores in low-income children aged 2-5 years (N = 250,029) and the concentration of neighborhood residents who spoke the same language as the childrens mothers. Using multi-level modeling and adjusting for childs gender and race/ethnicity, household education, neighborhood socioeconomic status, and year the child was examined, we found that percent of neighborhood residents who spoke the same language as the childs mother was negatively associated with BMI z-scores. This relation varied by childs race/ethnicity and mothers preferred language. The relation was linear and negative among children of English-speaking Hispanic mothers and Chinese-speaking mothers. However, for Hispanic children of Spanish-speaking mothers the relation was curvilinear, initially exhibiting a positive relation which reversed at higher neighborhood concentrations of Spanish-speaking residents. Our findings suggest that living in neighborhoods where residents share the same language may influence obesity-related behaviors (namely diet and physical activity) possibly through mechanisms involving social networks, support, and norms.

Influences of the neighbourhood food environment on adiposity of low-income preschool-aged children in Los Angeles County: a longitudinal study

Background Few studies have examined the association between the food environment and adiposity in early childhood, a critical time for obesity prevention. The objective of this study was to examine the longitudinal association between neighbourhood food environment and adiposity among low-income preschool-aged children in a major metropolitan region in the USA. Methods The study sample was 32 172 low-income preschool-aged children in Los Angeles County who had repeated weight and height measurements collected between ages 2 and 5 years through a federal nutrition assistance programme. We conducted multilevel longitudinal analyses to examine how spatial densities of healthy and unhealthy retail food outlets in the childrens neighbourhoods were related to adiposity, as measured by weight-for-height z-score (WHZ), while controlling for neighbourhood-level income and education, family income, maternal education, and childs gender and race/ethnicity. Results Density of healthy food outlets was associated with mean WHZ at age 3 in a non-linear fashion, with mean WHZ being lowest for those exposed to approximately 0.7 healthy food outlets per square mile and higher for lesser and greater densities. Density of unhealthy food outlets was not associated with child WHZ. Conclusions We found a non-linear relationship between WHZ and density of healthy food outlets. Research aiming to understand the sociobehavioural mechanisms by which the retail food environment influences early childhood obesity development is complex and must consider contextual settings.

Projecting the impact of hypothetical early life interventions on adiposity in children living in low-income households.

It is difficult to evaluate the effectiveness of interventions aimed at reducing early childhood obesity using randomized trials.

Influences of the neighborhood food environment on adiposity of low-income preschool-aged children in Los Angeles County: a longitudinal study

Background Few studies have examined the association between the food environment and adiposity in early childhood, a critical time for obesity prevention. The objective of this study was to examine the longitudinal association between neighbourhood food environment and adiposity among low-income preschool-aged children in a major metropolitan region in the USA. Methods The study sample was 32 172 low-income preschool-aged children in Los Angeles County who had repeated weight and height measurements collected between ages 2 and 5 years through a federal nutrition assistance programme. We conducted multilevel longitudinal analyses to examine how spatial densities of healthy and unhealthy retail food outlets in the childrens neighbourhoods were related to adiposity, as measured by weight-for-height z-score (WHZ), while controlling for neighbourhood-level income and education, family income, maternal education, and childs gender and race/ethnicity. Results Density of healthy food outlets was associated with mean WHZ at age 3 in a non-linear fashion, with mean WHZ being lowest for those exposed to approximately 0.7 healthy food outlets per square mile and higher for lesser and greater densities. Density of unhealthy food outlets was not associated with child WHZ. Conclusions We found a non-linear relationship between WHZ and density of healthy food outlets. Research aiming to understand the sociobehavioural mechanisms by which the retail food environment influences early childhood obesity development is complex and must consider contextual settings.

Baby-Friendly Hospital Initiative and Breastfeeding Among WIC-Participating Infants in Los Angeles County

Background: Breastfeeding rates among low-income infants lag behind national rates. Policies such as the Baby-Friendly Hospital Initiative (BFHI) improve breastfeeding and may benefit low-income populations such as those who participate in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). A recent effort exists to increase the number of Baby-Friendly designated hospitals in Los Angeles County (LAC). Research aim: This study aimed to determine whether the BFHI effort has had a beneficial effect on Baby-Friendly hospital practices in LAC hospitals and to determine if birthing hospitals’ Baby-Friendly designation status is associated with breastfeeding outcomes among WIC-participating children in LAC. Methods: Data came from the Los Angeles County WIC Survey (2008, 2011, 2014), which is conducted on a random sample of approximately 5,000 WIC families living in LAC. The prevalence of three Baby-Friendly hospital practices was examined between 2008 and 2014. Logistic regression was used to examine the association of birthing hospitals’ Baby-Friendly designation status with any breastfeeding and exclusive breastfeeding at 1, 3, and 6 months. Results: The rates of Baby-Friendly hospital practices have improved since 2008. Although no association existed with rates of any breastfeeding, being born in a hospital designated Baby-Friendly or in the process of obtaining this designation was significantly associated with an increased odds of exclusive breastfeeding at 1 and 3 months. Conclusion: The BFHI may help achieve recommended exclusive breastfeeding rates, especially for low-income populations. Additional strategies are needed to support low-income mothers in LAC with all levels of breastfeeding.

Response to Letter to the Editor by Joe Brew, Department of Epidemiology, University of Florida.

Dear Editors We are pleased that our paper has been deemed thought-provoking. Regarding the issues brought by Joe Brew, we would like to respond as follows: 1. Brew suggests that we should have used body mass index (BMI) percentiles instead of weight-for-height z-scores (WHZ). We disagree and stand behind our original statement that WHZ is a more appropriate measure for longitudinally assessing adiposity among young children. In the paper cited by Brew1 as justification for his argument, …

Influences of the neighbourhood food environment on adiposity of low-income preschool-aged children in Los Angeles County

Background Few studies have examined the association between the food environment and adiposity in early childhood, a critical time for obesity prevention. The objective of this study was to examine the longitudinal association between neighbourhood food environment and adiposity among low-income preschool-aged children in a major metropolitan region in the USA. Methods The study sample was 32 172 low-income preschool-aged children in Los Angeles County who had repeated weight and height measurements collected between ages 2 and 5 years through a federal nutrition assistance programme. We conducted multilevel longitudinal analyses to examine how spatial densities of healthy and unhealthy retail food outlets in the childrens neighbourhoods were related to adiposity, as measured by weight-for-height z-score (WHZ), while controlling for neighbourhood-level income and education, family income, maternal education, and childs gender and race/ethnicity. Results Density of healthy food outlets was associated with mean WHZ at age 3 in a non-linear fashion, with mean WHZ being lowest for those exposed to approximately 0.7 healthy food outlets per square mile and higher for lesser and greater densities. Density of unhealthy food outlets was not associated with child WHZ. Conclusions We found a non-linear relationship between WHZ and density of healthy food outlets. Research aiming to understand the sociobehavioural mechanisms by which the retail food environment influences early childhood obesity development is complex and must consider contextual settings.