Social Isolation, Brain Food Cue Processing, Eating Behaviors, and Mental Health Symptoms.

Importance: Perceived social isolation is associated with negative health outcomes, including increased risk for altered eating behaviors, obesity, and psychological symptoms. However, the underlying neural mechanisms of these pathways are unknown. Objective: To investigate the association of perceived social isolation with brain reactivity to food cues, altered eating behaviors, obesity, and mental health symptoms. Design, Setting, and Participants: This cross-sectional, single-center study recruited healthy, premenopausal female participants from the Los Angeles, California, community from September 7, 2021, through February 27, 2023. Exposure: Participants underwent functional magnetic resonance imaging while performing a food cue viewing task. Main Outcomes and Measures: The main outcomes included brain reactivity to food cues, body composition, self-reported eating behaviors (food cravings, reward-based eating, food addiction, and maladaptive eating behaviors), and mental health symptoms (anxiety, depression, positive and negative affect, and psychological resilience). Results: The study included 93 participants (mean [SD] age, 25.38 [7.07] years). Participants with higher perceived social isolation reported higher fat mass percentage, lower diet quality, increased maladaptive eating behaviors (cravings, reward-based eating, uncontrolled eating, and food addiction), and poor mental health (anxiety, depression, and psychological resilience). In whole-brain comparisons, the higher social isolation group showed altered brain reactivity to food cues in regions of the default mode, executive control, and visual attention networks. Isolation-related neural changes in response to sweet foods correlated with various altered eating behaviors and psychological symptoms. These altered brain responses mediated the connection between social isolation and maladaptive eating behaviors (ß for indirect effect, 0.111; 95% CI, 0.013-0.210; P = .03), increased body fat composition (ß, -0.141; 95% CI, -0.260 to -0.021; P = .02), and diminished positive affect (ß, -0.089; 95% CI, -0.188 to 0.011; P = .09). Conclusions and Relevance: These findings suggest that social isolation is associated with altered neural reactivity to food cues within specific brain regions responsible for processing internal appetite-related states and compromised executive control and attentional bias and motivation toward external food cues. These neural responses toward specific foods were associated with an increased risk for higher body fat composition, worsened maladaptive eating behaviors, and compromised mental health. These findings underscore the need for holistic mind-body-directed interventions that may mitigate the adverse health consequences of social isolation.

Lessons Learned From TranslateCovid, a Multilingual Online Resource Hub for Asian American and Pacific Islander Communities and Beyond.

The COVID-19 pandemic exacerbated health disparities among immigrant communities. Delivering accurate information and addressing misinformation on protective measures and vaccination to linguistically disadvantaged groups was critical for mitigating the effects of the pandemic. One group that was especially vulnerable to miscommunication about COVID-19 was non-native English-speaking immigrants. To address these disparities, the Asian American Studies Center and the Fielding School of Public Health at the University of California, Los Angeles, partnered to create a multilingual resource hub, TranslateCovid.org, to disseminate credible and reliable information about COVID-19 safety measures, the science behind the vaccines, and vaccine safety. We identified >1300 verified resources in 60 languages from government, academic, and nonprofit organizations and reposted them on the TranslateCovid website. We also developed public service announcement videos on handwashing, use of face masks, and social distancing in 10 languages and a fact sheet for frequently asked questions in 20 languages. We used a participatory approach to develop strategies for disseminating these resources. We discuss lessons learned, including strategies for forming government, community, and academic partnerships to support the timely development and dissemination of information. We conclude with a discussion on the unique role of universities in promoting equitable access to public health resources among immigrant communities in times of crisis.

Examination of community-level interventions addressing early childhood obesity in Los Angeles County.

Objective: To help inform decisions regarding the equitable implementation of obesity interventions, we examined whether interventions were equitably reaching the most vulnerable communities, identified communities that received fewer interventions than expected, and estimated the effect of 'dose' of interventions on obesity prevalence. Methods: We created a database to identify and characterize obesity-related interventions implemented in Los Angeles County from 2005 to 2015 linked to community-level sociodemographic and obesity prevalence data. We ran generalized linear models with a Gamma distribution and log link to determine if interventions were directed toward vulnerable communities and to identify communities that received fewer interventions than expected. We ran fixed-effects models to estimate the association between obesity prevalence and intervention strategy count among preschool-aged children enrolled in the Special Supplemental Nutrition Assistance Program for Women Infants and Children. Results: We found that interventions targeted vulnerable communities with high poverty rates and percentages of minority residents. The small cluster of communities that received fewer interventions than expected tended to have poor socioeconomic profiles. Communities which received more intervention strategies saw greater declines in obesity prevalence (ß = -0.023; 95 % CI: -0.031, -0.016). Conclusions: It is important to determine if interventions are equitably reaching vulnerable populations as resources to tackle childhood obesity become available. Evaluating the population impact of multiple interventions implemented simultaneously presents methodological challenges in measuring intervention dose and identifying cost-effective strategies. Addressing these challenges must be an important research priority as community-wide interventions involve multiple intervention strategies to reduce health disparities.

The role of breastfeeding support in racial/ethnic disparities in breastfeeding practices.

BACKGROUND: Persistent racial/ethnic disparities in breastfeeding practices in the United States are well documented but the underlying causes remain unclear. While racial/ethnic disparities are often intertwined with socioeconomic disparities in breastfeeding, studies suggest that lack of breastfeeding support from family, health care organizations and workplaces may contribute to racial/ethnic disparities in breastfeeding rates. No studies have investigated the extent to which racial/ethnic disparities in breastfeeding practices can be explained by breastfeeding support. METHODS: We used survey data from participants of a federal nutrition assistance program in Los Angeles County, the most populous county in the United States, to examine causal mechanisms underlying racial/ethnic disparities in breastfeeding in five groups: Spanish-speaking Latina, English-speaking Latina, Non-Hispanic White (NHW), Non-Hispanic Black (NHB) and Non-Hispanic Asian (NHA). Applying causal mediation analysis, this study estimated the proportion of racial/ethnic differences in breastfeeding ('any' breastfeeding, i.e., partial or exclusive) rates at 6 months that could be explained by differential access to breastfeeding support from family, birth hospitals and workplaces. RESULTS: NHB and English-speaking Latina mothers were less likely, and Spanish-speaking Latina mothers more likely to breastfeed through 6 months than NHW mothers. Lack of breastfeeding support from family, hospitals and workplaces accounted for approximately 68% of the difference in any breastfeeding rates at 6 months between NHW and NHB mothers and 36% of the difference between NHW and English-speaking Latina mothers. CONCLUSION: These findings highlight the importance of improving support from family, hospitals and workplaces for breastfeeding mothers to reduce racial/ethnic disparities in breastfeeding.

Discrimination exposure impacts unhealthy processing of food cues: crosstalk between the brain and gut.

Experiences of discrimination are associated with adverse health outcomes, including obesity. However, the mechanisms by which discrimination leads to obesity remain unclear. Utilizing multi-omics analyses of neuroimaging and fecal metabolites, we investigated the impact of discrimination exposure on brain reactivity to food images and associated dysregulations in the brain-gut-microbiome system. We show that discrimination is associated with increased food-cue reactivity in frontal-striatal regions involved in reward, motivation and executive control; altered glutamate-pathway metabolites involved in oxidative stress and inflammation as well as preference for unhealthy foods. Associations between discrimination-related brain and gut signatures were skewed towards unhealthy sweet foods after adjusting for age, diet, body mass index, race and socioeconomic status. Discrimination, as a stressor, may contribute to enhanced food-cue reactivity and brain-gut-microbiome disruptions that can promote unhealthy eating behaviors, leading to increased risk for obesity. Treatments that normalize these alterations may benefit individuals who experience discrimination-related stress.

Health selection on self-rated health and the healthy migrant effect: Baseline and 1-year results from the health of Philippine Emigrants Study.

Studies of migration and health focus on a "healthy migrant effect" whereby migrants are healthier than individuals not migrating. Health selection remains the popular explanation of this phenomenon. However, studies are mixed on whether selection occurs and typically examine migrants post-departure. This study used a novel pre-migration dataset to identify which health and social domains differ between migrants and their non-migrant counterparts and their contribution to explaining variance in self-rated health by migrant status at pre-migration and 1-year later. Data were used from the baseline and 1-year follow-up of the Health of Philippine Emigrants Study (HoPES). We used multivariable ordinary least squares regression to examine differences in self-rated health between migrants to the U.S. and a comparable group of non-migrants at baseline (premigration) and one year later, accounting for seven domains: physical health, mental health, health behavior, demographics, socioeconomic factors and healthcare utilization, psychosocial factors, and social desirability. A migrant advantage was present for self-rated health at baseline and 1-year. Accounting for all domains, migrants reported better self-rated health compared to non-migrants both at baseline (ß = 0.32; 95% CI = 0.22, 0.43) and at 1-year (ß = 0.28; 95% CI = 0.10, 0.46). Migrant status, health behavior, and mental health accounted for most of the variance in self-rated health both at baseline and 1-year follow-up. This analysis provides evidence of migrant health selection and nuanced understanding to what is being captured by self-rated health in studies of migrant health that should be considered in future research.

Evaluating the impact of community interventions on childhood obesity in populations living in low-income households in Los Angeles: A simulation study.

BACKGROUND: The complex multifactorial nature of childhood obesity makes community interventions difficult to evaluate using traditional approaches; innovative methods are needed. OBJECTIVE: To evaluate the impact of various interventions targeting childhood obesity-related behaviours, and classified as using a micro-level (e.g., home visitation programs) or macro-level (e.g., business practices) strategy, on obesity among children enrolled in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). METHODS: We simulated a population of 1500 children enrolled in WIC, with specific diet, physical activity, breastfeeding behaviours and body mass index z-scores (BMIz), following them from age 2 to 5 years. RESULTS: Combined interventions targeting breastfeeding appeared to be moderately effective, reducing BMIz by 0.03 (95% CI -005, -0.01). Two strategy-specific interventions, home visitation programs and business practices targeting obesity-related behaviours, appeared to be moderately effective at reducing BMIz by 0.04 (95% CI -0.06, -0.02) and 0.02 (95% CI -0.04, 0.00), respectively. Contrary to expectation, combining all micro and macro interventions appeared to have no impact or moderately increased the proportion of obesity/overweight among children. CONCLUSION: Interventions targeting breastfeeding behaviour were most effective when both micro and macro strategies were implemented. Interventions targeting obesity-related behaviours in general were effective for two strategies, home visitation and business practices.

Effects of prenatal exposure to pyrethroid pesticides on neurodevelopment of 1-year- old children: A birth cohort study in China.

Pregnant women have been ubiquitously exposed to pyrethroid pesticides. Previous studies, mainly based on third trimester measurements of maternal urinary pyrethroid metabolites, have reported inconsistent findings in the effects of prenatal pyrethroid exposure on children's neurodevelopmental outcomes. The purpose of this study was to clarify if pyrethroid exposure during the entire three trimesters of pregnancy may be associated with deleterious effects on infant neurodevelopmental status, particularly at a high dosage of exposure. We measured maternal urinary concentrations of pyrethroid metabolites in all trimesters of pregnancy and assessed children's neurodevelopment at one year of age using the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III). Multiple linear regression models were used to estimate the effects of metabolites (3-PBA, 4 F-3-PBA, cis-DBCA) in each trimester on BSID-III composite scores. Logistic regression analyses were applied to predict developmental delay vs non-delayed status (cut-off composite score of below 80 for developmental delay) based on the maternal levels of pyrethroid metabolites. In the first, second and third trimesters of pregnancy, the detection rates of pyrethroid metabolites were 94.7%, 90.7%, and 89.0%; the 50th percentiles of exposure level were 0.24 µg/g, 0.24 µg/g and 0.21 µg/g for 3-PBA, 0.14 µg/g, 0.17 µg/g and 0.15 µg/g for 4 F-3PBA, 0.21 µg/g, 0.25 µg/g and 0.19 µg/g for cis-DBCA respectively. In the second trimester, 3-PBA was inversely associated with Cognition and Language scores [ß = -3.34 (95% CI = -6.11, -0.57) and ß = -2.90 (95% CI = -5.20, -0.61), respectively], and significantly increased the risk of Cognition and Language developmental delay [OR= 1.64 (95% CI = 1.03, 2.62) and OR = 1.52 (95% CI = 1.06, 2.19), respectively]; cis-DBCA was inversely associated with Adaptive Behavior scores [ß = -0.73 (95% CI = -1.27, -0.19)], and significantly increased the risk of Adaptive Behavior developmental delay [OR= 1.11 (95% CI = 1.02, 1.21)]. When the maternal levels of pyrethroid metabolites were stratified into the regression models according to the 90th percentile of exposure, in the first trimester, Cognition and Motor scores were inversely associated with higher cis-DBCA [ß = -7.19 (95% CI = -12.97, -1.41) and ß = -8.20 (95% CI = -13.35, -3.05), respectively], Language scores were inversely associated with higher 3-PBA [ß = -6.01 (95% CI = -10.96, -1.06)]; in the second trimester, Cognition scores were inversely associated with higher cis-DBCA [ß = -6.64 (95% CI = -12.51, -0.76)], Language scores were inversely associated with higher 3-PBA [ß = -5.17 (95% CI = -10.07, -0.27)] and cis-DBCA [ß = -5.40 (95% CI = -10.28, -0.52)]. We concluded that pyrethroid exposure in the first and second trimesters was associated with poorer infants neurodevelopmental outcomes at one year of age, and these effects were particularly pronounced at high levels of pyrethroid exposure.

Understanding children's perspectives of the influences on their dietary behaviours.

OBJECTIVE: This study aimed to examine the intrapersonal, interpersonal, environmental and macrosystem influences on dietary behaviours among primary school children in Singapore. DESIGN: A qualitative interpretive approach was used in this study. Focus group discussions guided by the socio-ecological model (sem), of which transcripts were analysed deductively using the sem and inductively using thematic analysis to identify themes at each sem level. SETTING: Two co-educational public primary schools in Singapore. PARTICIPANTS: A total of 48 children (n 26 girls) took part in the semi-structured focus group discussions. Their mean age was 10·8 years (sd = 0·9, range 9-12 years), and the majority of the children were Chinese (n 36), along with some Indians (n 8) and Malays (n 4). RESULTS: Children's knowledge of healthy eating did not necessarily translate into healthy dietary practices and concern for health was a low priority. Instead, food and taste preferences were pivotal influences in their food choices. Parents had a large influence on children with regards to their accessibility to food, their attitudes and values towards food. Parental food restriction led to some children eating in secrecy. Peer influence was not frequently reported by children. Competitions in school incentivised children to consume fruits and vegetables, but reinforcements from teachers were inconsistent. The proximity of fast-food chains in the neighbourhood provided children easy access to less healthy foods. Health advertisements on social media rather than posters worked better in drawing children's attention. CONCLUSIONS: Findings highlighted important factors that should be considered in future nutrition interventions targeting children.

Neighborhood Contexts and Breast Cancer Among Asian American Women.

BACKGROUND: This study examines how neighborhood socioeconomic status (nSES) and ethnic composition are associated with breast cancer risk for Asian American women. METHODS: We linked individual level data from a population-based case-control study of breast cancer among Asian American women with neighborhood level data in the Greater San Francisco Bay Area (cases: n = 118, controls: n = 390). Multivariable logistic regression models examined the association between nSES, ethnic composition, and odds of having breast cancer. RESULTS: Asian American women living in neighborhoods with high nSES and high ethnic composition had the highest odds of breast cancer, compared to those living in neighborhoods with high nSES and low ethnic composition (OR = 0.34, 95% CI [0.16-0.75]) or in neighborhoods with low nSES and high ethnic composition (OR = 0.37, 95% CI [0.17-0.83]). DISCUSSION: Neighborhood socioeconomic and ethnic contexts are associated with breast cancer for Asian American women. We discuss explanations and avenues for future research.

Mixed Infant Feeding Is Not Associated With Increased Risk of Decelerated Growth Among WIC-Participating Children in Southern California.

Background: The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) provides nutrition assistance to half of infants born in the United States. The nationally representative WIC Infants and Toddler Feeding Practices Study-2 (ITFPS-2) reported a caloric deficit at 7 months among infants receiving WIC mixed feeding packages, suggesting these infants may be at risk for growth deceleration/faltering. Methods: Longitudinal administrative data collected prospectively from WIC participants in Southern California between 2010 and 2019 were used (n = 16,255). Infant lengths and weights were used to calculate weight-for-length (WLZ), weight-for-age (WAZ) and length-for-age (LAZ) z-scores at different time points. Growth deceleration/faltering was determined at 9, 12, 18, and 24 months by the change in z-score from the last measurement taken ≤ 6 months of age. Infant feeding was categorized by the food package (breastfeeding, mixed feeding, and formula feeding) infants received from WIC at 7 months. Poisson regression models were used to evaluate the association between WIC infant package at 7 months and deceleration/faltering at 9, 12, 18, and 24 months. Results: The proportion of infants displaying decelerated/faltering growth was low for all infant food package groups. Receiving the WIC mixed feeding package at 7 months of age was not associated with WLZ, WAZ, and LAZ deceleration/faltering growth. Conclusions: Growth deceleration/faltering rates were very low among WIC participating children in Southern California, highlighting the critical role of nutrition assistance in supporting adequate growth in early childhood.

Regional differences in the impact of the COVID-19 pandemic on food sufficiency in California, April-July 2020: implications for food programmes and policies.

OBJECTIVE: To evaluate regional differences in factors associated with food insufficiency during the initial months of the COVID-19 pandemic among three major metropolitan regions in California, a state with historically low participation rates in the Supplementation Nutrition Assistance Program, the nation's largest food assistance programme. DESIGN: Analysis of cross-sectional data from phase 1 (23 April-21 July 2020) of the US Census Household Pulse Survey, a weekly national online survey. SETTING: California, and three Californian metropolitan statistical areas (MSA), including San Francisco-Oakland-Berkeley, Los Angeles-Long Beach-Anaheim and Riverside-San Bernardino-Ontario MSA. PARTICIPANTS: Adults aged 18 years and older living in households. RESULTS: Among the three metropolitan areas, food insufficiency rates were lowest in the San Francisco-Oakland-Berkeley MSA. Measures of disadvantage (e.g., having low-income, being unemployed, recent loss of employment income and pre-pandemic food insufficiency) were widely associated with household food insufficiency. However, disadvantaged households in the San Francisco Bay Area, the area with the lowest poverty and unemployment rates, were more likely to be food insufficient compared with those in the Los Angeles-Long Beach-Anaheim and Riverside-San Bernardino-Ontario MSA. CONCLUSIONS: Food insufficiency risk among disadvantaged households differed by region. To be effective, governmental response to food insufficiency must address the varied local circumstances that contribute to these disparities.

Longitudinal trajectories of adiposity-related measures from age 2-5 years in a population of low-income Hispanic children.

BACKGROUND: We estimated longitudinal trajectories of body mass index (BMI) z-score and percentile, weight for height (WFH) z-score and percentile, and percentage of the 95th BMI percentile (BMIp95) among low-income Hispanic children ages 2-5 years to provide normative data for this population and compare the behavior of different measures. METHODS: Longitudinal height and weight measurements obtained from 18,072 Hispanic children aged 2-5 years enrolled in the Special Supplemental Nutrition Program for Women, Infants and Children in Los Angeles County were analyzed. Trajectories of adiposity-related measures were estimated using mixed models, stratified by sex and BMI percentile at age 2 years. RESULTS: For children in the 5th-85th BMI percentile at age 2 years, all adiposity-related measures rose during ages 2-3.5 years; during ages 3.5-5 years, BMI-based measures increased, BMIp95 decreased, and WFH-based measures were stable. For children exceeding the 85th BMI percentile at age 2 years, measures generally trended downward during ages 2-5 years, except for BMIp95, which had variable trends. CONCLUSIONS: Adiposity measures changed at different rates as children grew during ages 2-3.5 years compared to ages 3.5-5 years, and different measures displayed different trends. Studies should consider examining multiple measures and focusing on change relative to a comparison group. IMPACT: To address the childhood obesity epidemic, information on normative trajectories of adiposity-related measures in at-risk populations of young children is needed. Longitudinal analysis of data collected from low-income Hispanic children during ages 2-5 years revealed different patterns for different adiposity measures and for ages 2-3.5 years versus 3.5-5 years. Child obesity studies should consider examining multiple adiposity measures and focus on change relative to a comparison group to avoid misinterpreting longitudinal patterns.

The role of income and neighbourhood poverty in the association between the 2009 Special Supplemental Nutrition Program for Women, Infants and Children (WIC) food package change and child obesity among WIC-participating children in Los Angeles County, 2003-2016.

OBJECTIVE: To determine whether a previously reported association between the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) food package change and reduced child obesity risk among WIC-participating children in Los Angeles County holds across levels of family income and neighbourhood poverty. DESIGN: Analysis of prospectively collected WIC administrative data. The outcome was obesity at age 4 years (BMI-for-age ≥ 95th percentile). Poisson regression was applied to a matched sample (n 79 502) to determine if the association between the WIC food package change and child obesity was modified by family income (<50 % federal poverty level (FPL), 50-100 % FPL, >100 % but <185 % FPL) and neighbourhood poverty. SETTING: Los Angeles County, California. PARTICIPANTS: Children who participated in WIC in Los Angeles County between 2003 and 2016; children were grouped as receiving the old WIC food package (2003-2009) or the new WIC food package (2010-2016). RESULTS: Receiving the new WIC food package (i.e., post-2009) was associated with 7-18 % lower obesity risk across all family income categories. Neither family income nor neighbourhood poverty significantly modified the association between the WIC food package and child obesity. However, certain sub-groups seemed to benefit more from the food package change than others. In particular, boys from families with income above poverty but residing in the poorest neighbourhoods experienced the greatest reductions in obesity risk (relative risk = 0·77; 95 % CI 0·66, 0·88). CONCLUSIONS: The WIC food package revisions were associated with reduced childhood obesity risk among all WIC-participating families in Los Angeles County, across levels of income eligibility and neighbourhood poverty.

Impact of a Scalable, Multi-Campus "Foodprint" Seminar on College Students' Dietary Intake and Dietary Carbon Footprint.

BACKGROUND: Dietary patterns affect both human health and environmental sustainability. Prior research found a ten-unit course on food systems and environmental sustainability shifted dietary intake and reduced dietary carbon footprint among college students. This research evaluated the impact of a similar, more scalable one-unit Foodprint seminar taught at multiple universities. METHODS: We used a quasi-experimental pre-post nonequivalent comparison group design (n = 176). As part of the Menus of Change University Research Collaborative, research was conducted at three university campuses in California over four academic terms. All campuses used the same curriculum, which incorporates academic readings, group discussions, and skills-based exercises to evaluate the environmental footprint of different foods. The comparison group comprised students taking unrelated one-unit courses at the same universities. A questionnaire was administered at the beginning and end of each term. RESULTS: Students who took the Foodprint seminar significantly improved their reported vegetable intake by 4.7 weekly servings relative to the comparison group. They also reported significantly decreasing intake of ruminant meat and sugar-sweetened beverages. As a result of dietary shifts, Foodprint seminar students were estimated to have significantly decreased their dietary carbon footprint by 14%. CONCLUSIONS: A scalable, one-unit Foodprint seminar may simultaneously promote environmental sustainability and human health.

Every month matters: longitudinal associations between exclusive breastfeeding duration, child growth and obesity among WIC-participating children.

BACKGROUND: Research has found breastfeeding to be protective of obesity; however, this link remains contentious. We examined longitudinal associations between exclusive breastfeeding duration, growth trajectories and obesity at 4 years among children participating in the Special Supplemental Nutrition Program for Women, Infants and Children (WIC), and whether these associations differed in the context of the 2009 WIC food package change, implemented to improve alignment with dietary guidelines and promote breastfeeding. METHODS: Longitudinal data from 260 935 WIC-participating children in Los Angeles County, California, 2003-2016, were used to assess the relationship between duration of receipt of the fully breastfeeding package (an exclusive breastfeeding proxy) with childhood growth and obesity using mixed effects and Poisson regression models. RESULTS: Children exclusively breastfed for longer duration had healthier growth trajectories and lower obesity risk at age 4. Compared with infants with no fully breastfeeding package receipt, any receipt (a breastfeeding initiation proxy) was associated with reduced obesity risk. Obesity risk was lowest for boys and girls exclusively breastfed for 7 (risk ratio (RR)=0.73, 95% CI=0.64 to 0.82) and 13 months (RR=0.63, 95% CI=0.58 to 0.69), respectively. Exclusive breastfeeding duration increased, but associations between exclusive breastfeeding duration and growth and obesity were not modified, following the 2009 WIC food package change. CONCLUSION: Increased duration of exclusive breastfeeding was associated with reduced obesity risk. The greatest incremental benefit was observed going from none to any exclusive breastfeeding, and the maximum cumulative benefit was among children receiving the fully breastfeeding package for more than 6 months. Breastfeeding promotion in WIC remains important for obesity prevention.

The neighborhood food environment modifies the effect of the 2009 WIC food package change on childhood obesity in Los Angeles County, California.

BACKGROUND: Food packages provided by the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) were revised in 2009 to better align them with the Dietary Guidelines for Americans. This study was conducted to evaluate whether the effect of the food package change on childhood obesity varied by the food environment in the neighborhoods where WIC-participating children live. METHODS: Administrative data from participating children in Los Angeles County, California (2003-2016) were merged with geocoded food vendor information by neighborhood of residence. Obesity risk at age 4 was compared between children receiving old (2003-2009) and new (2010-2016) WIC food packages using sex-stratified Poisson regression models, with interaction terms between WIC package and neighborhood density (number per square mile) of healthy and unhealthy food outlets. RESULTS: The new food package was associated with a significant decrease in obesity risk. Among boys, the new food package was associated with 8 to 18% lower obesity risk at all healthy and unhealthy food outlet densities, and the association was not modified by neighborhood food outlet density. Among girls, the association of the new food package with obesity risk was protective in neighborhoods with high healthy and low unhealthy food outlet densities, and adverse in neighborhoods with high unhealthy and low healthy food outlet densities. The effect of the new food package among girls was modified by unhealthy food outlet density, with significantly smaller (p-value = 0.004) decreases in obesity risk observed in neighborhoods with higher unhealthy food outlet density. CONCLUSIONS: The impact of the food package change was modified by the neighborhood food environment among girls only. Future policy changes should incorporate consideration of ways to mitigate potentially inequitable geographic distribution of the health benefits of policy changes.

Estimating the population impact of hypothetical breastfeeding interventions in a low-income population in Los Angeles County: An agent-based model.

BACKGROUND: Breastfeeding has clear benefits. Yet, breastfeeding practices fall short of recommendations in low-income populations including participants of the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). To promote breastfeeding, it is important to understand breastfeeding-related behaviors such as initiation and maintenance within the context of a complex societal system. For individual women, making choices about infant feeding (whether to breastfeed or formula-feed a newborn, or when to stop breastfeeding) is a dynamic process involving interactions with health professionals, family, peers and workplaces. Integrating behavioral change theories with systems science tools such as agent-based modeling can help illuminate patterns of breastfeeding behaviors, identify key factors affecting breastfeeding behaviors within this complex dynamic system, and estimate the population impact of hypothetical interventions. METHODS: An agent-based model (ABM) was developed to investigate the influences of multiple levels of factors affecting breastfeeding behaviors among WIC participants. Health behavioral change theories were applied and stakeholder input obtained to improve the model, particularly during the conceptual design and model specification steps. The model was then used to identify critical points for intervention and assess the effects of five common interventions (improving knowledge through education, implementing Baby-Friendly Hospital Initiative practices, providing postpartum breastfeeding counselling, strengthening partner support, and fostering supportive workplace environments.). RESULTS: The ABM developed in this study produced outcomes (i.e., breastfeeding rates) that were concordant with empirical data. Increasing the coverage of the five selected interventions produced various levels of improvement in breastfeeding practices in the target population. Specifically, improving breastfeeding knowledge had a positive impact on women's intent to breastfeed, while increasing the availability of the Baby-Friendly Hospital Initiative improved breastfeeding initiation rates. However, neither of these two interventions showed a significant impact on breastfeeding maintenance, which was supported by postpartum breastfeeding counseling, partner support and a supportive workplace environment. These three intervention strategies each improved breastfeeding rates at 6 months from 55.6% to 57.1%, 59.5% and 59.3%, respectively. Increasing the coverage of multiple interventions simultaneously had a synergistic effect on breastfeeding maintenance with their effects being greater than the cumulative effects of increasing the coverage of these interventions individually. CONCLUSION: The ABM we developed was helpful for understanding the dynamic process of decision-making regarding infant feeding modalities in a low-income population, and for evaluating the aggregated population-level impact of breastfeeding promotion interventions.

The new child food package is associated with reduced obesity risk among formula fed infants participating in the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) in Los Angeles County, California, 2003-2016.

BACKGROUND: The Special Supplemental Nutrition Program for Women, Infants and Children (WIC) changed the food packages provided to its participants in 2009, to better align them with the Dietary Guidelines for Americans. Previous research found that the 2009 WIC food package change was associated with reduced obesity risk, particularly among breastfed infants but also among those who were never breastfed. The objective of this study was to determine if the new child food package introduced in 2009, including more produce and whole grains for 1-4-year old children, was associated with healthier growth trajectories and reduced obesity risk at age 4 years among children who were exclusively formula fed during infancy. METHODS: Administrative data on WIC-participating children in Los Angeles County, 2003-2016, were used (N = 74,871), including repeated measures of weight and length (or height); child's age, gender, and race/ethnicity; maternal education and language; and family poverty. Gender-stratified spline mixed models were used to examine weight-for-height z-score (WHZ) growth trajectories from 0 to 4 years and Poisson regression models were used to assess obesity (BMI-for-age > 95th percentile) at age 4. The main independent variable was duration of receipt (dose) of the new child package, categorized as 0, > 0 to < 1, 1 to < 2, 2 to < 3, 3 to < 4, and 4 years. RESULTS: WHZ growth trajectories were similar for children across new child package dose groups. Boys and girls who were fully formula fed during infancy but received the new child food package for 4 years had a 7% (RR = 0.93; 95%CI = 0.89-0.98) and a 6% (RR = 0.94; 95%CI = 0.89-0.99) lower obesity risk, respectively, compared to children who received the new child food package for 0 years. There were no differences in obesity risk for children receiving < 4 years of the new child package vs. 0 years. CONCLUSIONS: Providing healthy foods during childhood to children who were exclusively formula fed as infants was associated with modest improvements in obesity outcomes. While breastfeeding promotion should still be prioritized among WIC participants, providing healthy foods during childhood may provide health benefits to formula fed children, who comprise a sizeable proportion of children served by WIC.