May C Wang

• DrPH
• Professor (Full) at University of California, Los Angeles

Introduction. Consumption of sugar-sweetened beverages (SSBs) contributes to weight gain, obesity, and diabetes. Soda tax has been proposed to reduce consumption of SSBs. What remains unclear is whether the soda tax has an effect on health and health care costs. We evaluated the cost-effectiveness of a 1-cent-per-ounce soda tax on obesity and diabe...

Introduction The aim of this study was to understand the prevalence and content of corporate social responsibility statements in the top-selling chain restaurants between 2012 and 2018 to inform the ways restaurants can impact population health. Methods The study used a web scraping technique to abstract relevant text information (n=6,369 text sec...

Background Discrimination is a recognized psychosocial stressor that has been linked to various negative health outcomes. This study explored the impact of discrimination on gut health, specifically focusing on microbiome changes, predicted metagenomic differences, transcriptomic profiles, and the potential for using a multi-omic approach to predic...

Background Cardiovascular diseases (CVDs) are the leading cause of death in the USA, and high blood pressure is a major risk factor for CVD. Despite the overall declining rates of CVD mortality in the USA in recent years, marked disparities between racial and ethnic groups persist, with black adults having a higher mortality rate than white adults....

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 COVI...

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...

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...

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 d...

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...

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 pro...

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 Franci...

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...

The Healthier Dining Programme (HDP) was launched to increase the availability and accessibility of healthier foods and beverages at food centers in Singapore. Our study's objective was to evaluate effects of the HDP on out-of-home dietary intakes of consumers at an institute of higher learning using a cluster-randomized trial. Six food centers at...

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,...

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 program. Design...

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 neighborhood poverty. Design Analysis of prospec...

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. Longitudinal height...

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),...

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 nei...

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...

Abstract 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 amon...

Background: In 2009, the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) food packages were updated. WIC-participating children in Los Angeles County receiving the new food package, compared with the old, had lower obesity risk at age 4. Objective: To determine if the association between the new WIC food package and...

Purpose The Health of Philippine Emigrants Study (HoPES) longitudinally investigates over 3 years whether migrating from the Philippines to the USA results in increased risk for obesity relative to non-migrants in the Philippines. The study is designed to test the healthy immigrant hypothesis by collecting health measures from migrants starting fro...

Classification systems can be useful for evaluating and communicating the impact of interventions. We describe how a typology was created to inform the development of a community intervention dose index (CIDI) intended to measure the strength of impacts attributed to multiple childhood obesity intervention strategies implemented in a large, diverse...

Immigrants to the United States may have an advantage in terms of healthier weight, but tend to gain excessive weight after arrival, and may suffer from obesity and related health conditions. Acculturation theory suggests that this increase in obesity risk is due to adoption of unhealthy western dietary behaviors, and assumes that "eastern/traditio...

Background In 2009, for the first time since the program's inception in 1974, the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) changed their food packages, providing food options better aligned with the 2005 Dietary Guidelines for Americans. Objective The aim of this study was to evaluate whether the 2009 WIC food p...

Objective To assess whether the effect of the 2009 women, infants, and children (WIC) food package change on obesity outcomes varies by initial weight status and gender. Methods Using 2003 to 2016 data from Los Angeles County, we compared growth trajectories and obesity at age 4 years among children exposed to WIC after the food package change (n...

There is growing evidence that prenatal participation in the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) reduces the risk of adverse birth outcomes. With recent changes in health care, rising health care costs, and increasing rates of prematurity in the U.S., there is urgency to estimate the potential cost savings a...

Background: The Special Supplemental Nutrition Program for Women, Infants and Children (WIC) is a federal nutrition assistance program which provides supplemental food and nutrition services to children 0-5 years and their mothers, living in low-income households. In October of 2009, WIC food packages were changed to be better aligned to the Dietar...

Despite high rates of housing-cost burden in the United States, little is known regarding its impact on childhood obesity. In this article, we determine whether low-income 2–5-year-olds living in housing-cost burdened households are more likely to be obese and examine the potential moderators and behavioral and psychosocial mediators of this relati...

Inorganic arsenic (iAs) is carcinogenic and highly concentrated in rice. Dietary exposure to iAs is concerning among adolescents due to their developmental stage and iAs’s long-latency effects. This paper aimed to assess iAs exposure from rice and related lifetime cancer risks (LCR) among adolescents in Kunming, China. A comprehensive literature re...

Background: Immigrants to the United States are usually healthier than their U.S.-born counterparts, yet the health of immigrants declines with duration of stay in the U.S. This pattern is often seen for numerous health problems such as obesity, and is usually attributed to acculturation (the adoption of "American" behaviors and norms). However, a...

Background: Obesity prevalence among low-income preschool-aged children in the United States decreased between 2010 and 2014. However, this decreasing trend may be varied across socioeconomic subgroups. This study examined trends in obesity prevalence among low-income children from 2003 to 2014 by child's age and household and neighborhood socioec...

Objective While economic crises can increase socio-economic disparities in health, little is known about the impact of the 2008–09 Great Recession on obesity prevalence among children, especially low-income children. The present study examined whether socio-economic disparities in obesity among children of pre-school age participating in a federal...

The recognition of the role of the environment in contributing to the obesity epidemic has led to increasing efforts to address obesity through environmental or place-based approaches in the past decade. This has challenged the use of the quasi-experimental design for evaluating community interventions. The objective of this study is to describe th...

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...

This study examined the relationship between racial/ethnic residential segregation and access to health care in rural areas. Data from the Medical Expenditure Panel Survey were merged with the American Community Survey and the Area Health Resources Files. Segregation was operationalized using the isolation index separately for African Americans and...

Background Participation in the Supplemental Nutrition Assistance Program (SNAP) has been linked to an increased risk of obesity, but not much is known about the mechanisms behind this association. The objective of this study was to determine if the neighborhood density of unhealthy food outlets modifies the association between obesity and particip...

Background Although increasing access to electronic benefit transfer (EBT) at farmers’ markets has become a popular strategy for encouraging healthy eating, its relationships to a number of dietary behaviors in low-income populations are not well understood. Objective To describe the frequency of and relationships between EBT access, fruit and veg...

Objectives: To examine whether living in a rural versus urban area differentially exposes populations to social conditions associated with disparities in access to health care. Methods: We linked Medical Expenditure Panel Survey (2005-2010) data to geographic data from the American Community Survey (2005-2009) and Area Health Resource File (2010...

Background: It is difficult to evaluate the effectiveness of interventions aimed at reducing early childhood obesity using randomized trials. Objective To illustrate how observational data can be analysed using causal inference methods to estimate the potential impact of behavioural 'interventions' on early childhood adiposity. Methods We used lon...

Introduction: Smartphone applications (apps) facilitate the collection of data on multiple aspects of behavior that are useful for characterizing baseline patterns and for monitoring progress in interventions aimed at promoting healthier lifestyles. Individual-based models can be used to examine whether behavior, such as diet, corresponds to certa...

Model coefficients and confidence intervals. (PDF)

While mother's perception of child's weight is important for the success of early childhood obesity prevention programs, few studies have examined that of Asian Americans. Our study examined their perception and compared it to that of mothers of other racial/ethnic groups. Cross-sectional study of 2,051 randomly selected mothers of children aged 2-...

Most studies of immigrant health are cross- sectional and fail to collect information prior to migration, leading to potential bias and confounding. The present pilot study examines the feasibility of studying migrants prospectively, with baseline data collected before migration. The study followed two cohorts of Filipinos for one year, a migrant c...

Although many studies have examined the relationship of adiposity with neighborhood socioeconomic context in adults, few studies have investigated this relationship during adolescence. Using 10-year annual measurements of body mass index, expressed as z-scores (BMIz), obtained from 775 black and white participants of the National Heart, Lung, and B...

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 mor...

Introduction: The purpose of this study is to compare the metabolic risk profile between Asian and Non-Hispanic white adults in the United States. Methods: This study used the NHANES 2011-2012 adult data for Asians (n=827) and Non-Hispanic Whites (n=2108). Linear regression was used to calculate mean differences between Asian and Non-Hispanic Whi...

In Los Angeles County (LAC), considerable neighborhood variation in obesity rates among low income preschool-aged children who participate in the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) provides an opportunity for investigating the impact of community interventions and policies on these children within various c...

Background: Child obesity is a major public health problem. While research has found that chronic psychosocial stress is associated with obesity in adults, relatively little is known about how it affects the risk of childhood obesity. Understanding its impact during adolescence is especially important as this period is characterized by rapid physic...

In Los Angeles County (LAC), considerable neighborhood variation in obesity rates exists among low-income preschool-aged children who participate in the Special Supplemental Nutrition Program for Women, Infants and Children. Differences in exposure to a myriad of community interventions and policies that have been implemented since 2003, in respons...

INTRODUCTION: Culturally-specific food environment survey instruments are important tools for studying changing food availability and pricing. Here, we present findings from an effort to develop and evaluate food environment survey instruments for use in a rapidly developing city in southwest China. METHODS: We developed two survey instruments (f...

As countries develop economically and increasing numbers of women enter the workforce, children are partly being cared for by someone other than their mother. Little is known about the impact of this shift in child-care provider on children’s nutrition. This study presents findings from a case study of Singapore, a small country that has experience...

Exposure to US culture is negatively associated with fruits and vegetables (F&V) intake. Our goal was to investigate how parent's nativity and length of stay in the US influences preschoolers' F&V intake. We analyzed survey data from 2,352 children, aged 36-60 months, who participate in the Supplemental Nutrition Program for Women, Infants and Chil...

Human behavioral interventions aimed at improving health can benefit from objective wearable sensor data and mathematical models. Smartphone-based sensing is particularly practical for monitoring behavioral patterns because smartphones are fairly common, are carried by individuals throughout their daily lives, offer a variety of sensing modalities,...

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 regi...

Recent federal initiatives have used estimates of population reach as a proxy metric for intervention impact, in part to inform resource allocation and programmatic decisions about competing priorities in the community. However, in spite of its utility, population reach as a singular metric of intervention impact may be insufficient for guiding mul...

Previous studies have established that acculturation is associated with dietary intake among Mexican immigrants and their offspring, but few studies have investigated whether food purchasing, food preparation or food-related values act as mechanisms of dietary acculturation. We examine the relationship between language use and a wide range of food...

The primary objective of this analysis was to examine the burden of diabetes among Asians and Asian subgroups in Los Angeles County, which has the largest county population of Asians in the U.S. Data were analyzed from 6cycles of the Los Angeles County Health Survey, 1997-2011 (n=47,282). Asian adults (n=4,672) were categorized into the following e...

Given the rapid pace of urbanization and Westernization and the increasing prevalence of obesity, there is a need for research to better understand the influence of the built environment on overweight and obesity in world's developing regions. Culturally-specific food environment survey instruments are important tools for studying changing food ava...

While child and adolescent obesity is a serious public health concern, few studies have utilized parameters based on the causal inference literature to examine the potential impacts of early intervention. The purpose of this analysis was to estimate the causal effects of early interventions to improve physical activity and diet during adolescence o...

Objectives: We assessed the effect of the new Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) food package, implemented in October 2009, on breastfeeding outcomes among a predominately Latina sample of WIC participants in Los Angeles County, California. Methods: We used data from 5020 WIC participants who were inter...

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...

A devastating earthquake struck west China in 2008. Reconstruction efforts have focused on urbanization and modernization, hastening economic growth in the area. This rapid growth provides a unique opportunity to explore the potential impact of rapid environmental changes on metabolic disease risk. The study objective was to gather qualitative info...

Obesity has been declared a global epidemic by the World Health Organization, and rates have also been rising among Asian Americans. In this chapter, we will discuss how obesity is defined and measured and if current definitions of obesity apply to Asian Americans; how prevalent obesity is among Asian Americans; why obesity is such a major public h...

The rising rates of obesity and chronic disease among Asian Americans (AA) and Pacific Islanders (PI) appear to follow a different pattern from the rest of the population. Additionally, they differ among the various AAPI subpopulations. This study will examine the relationship between physical activity level and diabetes status among the AAPI sub...

INTRODUCTION: For built environment studies, the locations of different food environment factors matter. Issues associated with using secondary databases such as misclassification and geospatial inaccuracy hinder researchers from assessing food environment precisely; yet field audits are resource intensive and time-consuming. The purpose of this st...

Background. Type 2 diabetes is a growing concern among medically underserved Chinese Americans. However, very few interventions have been developed or adapted for Chinese Americans with diabetes. Objective. To use a participatory research approach to evaluate the effectiveness of a culturally tailored, linguistically appropriate model for diabetes...

The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) serves 50% of infants and 25% of preschool-aged children in the United States and collects height and weight measurements from eligible children every 6 mo, making WIC data a valuable resource for studying childhood growth and obesity. We assessed the accuracy of meas...

Studies have reported differences in obesity risk and food environments by neighborhood income. However, few studies have investigated these relationships in only low-income neighborhoods. Do extremely low-income neighborhoods differ from low-income neighborhoods that are less deprived? Data on low-income preschool-aged children who participated in...

While it is increasingly recognized that the neighborhood food environment may influence accessibility to healthy foods and hence obesity risk, there is a dearth of research on the contributions of neighborhoods to obesity development in early childhood. Preventive approaches in early childhood may be the most effective strategy for addressing the...

INTRODUCTION: Certain restaurant densities are used as proxies for exposure to healthy or unhealthy foods. While different datasets have been used to quantify restaurant density, the differences between these datasets have not been systematically examined. We compared four sources of "restaurant" listings in Berkeley, California, assessing their co...

Neighborhood environments are increasingly recognized as important contributors to adult obesity risk. However, less has been reported on their contributions to child obesity. Using 2000 Census data and 2003-2009 data from the WIC program in Los Angeles County, we examined the relationship between BMI z-scores in low-income children aged 2-5 years,...

Asians who have a healthy body mass index (BMI) range have been observed to have higher levels of obesity and risk of cardiovascular disease than whites, which suggests that the relation between BMI and adiposity may be different for Asians. The primary aim of this study was to investigate the influence of childhood and adolescent exposure to a wes...

This pilot study explores the roles of family socioeconomic status (SES) in influencing dietary consumption patterns in 60 Chinese elementary school-aged children (ages 6-11) in Chengdu, China. Two interviewer-administered questionnaires were specially developed to gather sociodemographic and food frequency data. Children from low SES families cons...

The current epidemic of childhood overweight has launched a variety of school-based efforts to address the issue. This study reports on the first 2 years of a 3-year evaluation of one school district's comprehensive intervention to transform school foodservices and dining experiences, offer cooking and gardening programs, and integrate nutrition an...

To investigate differences in childhood overweight and obesity prevalence among Asian/Pacific Islander (API) subgroups. Cross-sectional secondary data analysis. California public school children participating in an annual state-mandated physical fitness testing program which included measured height and weight. 5th, 7th and 9th grade students atten...

The School Lunch Initiative (SLI) is a public/private partnership among the Berkeley Unified School District, the Chez Panisse Foundation and the Center for Ecoliteracy. The objectives are to change the way children learn about food and change what they eat in school. This presentation reports the results of the SLI Evaluation Project, a three-year...

This study used digital photography to assess fruit and vegetable consumption during school lunch to evaluate the impact of cooking and gardening programs. 117 5th graders participated from 4 elementary schools in a diverse mid-sized city; 2 schools had cooking and gardening classes (intervention), and 2 were comparison schools. All 4 schools had b...

Bone mineral content (BMC) and areal bone mineral density (BMD) have been reported to be lower in Asian than in Caucasian adults. To determine if racial differences in bone mass are present in younger subjects and whether they reflect differences in estimated volumetric bone density or in bone size, we compared measurements of bone mineral in healt...

School foodservice offers an ideal yet underutilized setting for experiential learning around food for children and for engaging parents in modeling healthy eating at home. The goal of the Nutrition Education in School Foodservice project was to take advantage of the potential of school foodservice settings to positively influence children's eating...

It is widely believed that broad societal changes and major shifts in worldwide nutrition and physical activity are driving the current epidemic of obesity (World Health Organization, 2003). Prevention strategies based solely on individual and family responsibility for change will not be maximally effective and must be supported by broader-based en...

Early menarche is a risk factor for breast cancer. We investigated the variation in age at menarche by socioeconomic status (SES) and race. A cohort study was conducted on 1,091 black and 986 white girls from the three sites in the United States as part of the NHLBI Growth and Health Study (NGHS), who were aged 9-10 years at baseline and followed t...

The School Lunch Initiative (SLI) is a multi-component program designed by the Berkeley Unified School District (BUSD), the Chez Panisse Foundation, and the Center for Ecoliteracy. The SLI Evaluation Project is a three-year effort to evaluate the SLI, aiming to examine changes in student food-related knowledge, attitude, and behavior related to exp...

Television watching, a sedentary activity, has been associated with overweight in children. While the family environment is known to influence television watching, little is known about the influence of the neighbourhood environment. This study is an exploratory examination of the association of socioeconomic characteristics of the neighbourhood en...

Background: Low-income residents of neighborhoods lacking a full-service grocery store may find it difficult to access healthy and fresh foods. However, will the mere opening of a full-service grocery store in such neighborhoods promote healthy food behaviors? This pilot study primarily sought to: (1) determine if food purchasing and consumption pa...

These analyses were designed to assess the obesity burden and highlight determinants of increased BMI and obesity (BMI ≥ 95th percentile with respect to age and gender) in children and adolescents living in California. The California Health Interview Survey (CHIS) 2001 data (n=5705 children, n=4860 adolescents) were analyzed in STATA 9.2. Overall,...

This paper examines trends in the neighbourhood food store environment (defined by the number and geographic density of food stores of each type in a neighbourhood), and in food consumption behaviour and overweight risk of 5779 men and women. The study used data gathered by the Stanford Heart Disease Prevention Program in four cross-sectional surve...

To determine whether socioeconomic and food-related physical characteristics of the neighbourhood are associated with body mass index (BMI; kg/m(2)) independently of individual-level sociodemographic and behavioural characteristics. Design and Observational study using (1) individual-level data previously gathered in five cross-sectional surveys co...

Few studies have systematically used a total diet approach to classify adolescent dietary patterns. We examined dietary patterns in relation to nutrient intakes and adiposity in the National Heart, Lung, and Blood Institute Growth and Health Study cohort of 2371 black and white girls recruited at 9-10 y of age and followed for 10 y. Serial measurem...

With the rapidly increasing prevalence of obesity in the United States, and the minimal success of education-based interventions, there is growing interest in understanding the role of the neighborhood food environment in determining dietary behavior. This study, as part of a larger study, identifies historical data on retail food stores, evaluates...

Our objectives were (1) to examine the associations of education and income with bone health in non-Hispanic White, non-Hispanic Black and Mexican-American postmenopausal women, (2) to determine if any observed associations can be explained by behavioral factors such as calcium intake and physical activity and (3) to determine if government food as...

Although obesity is associated with increased risk of many chronic diseases including cardiovascular disease, diabetes, hypertension, and cancer, there is little evidence to suggest that obesity increases risk of osteoporosis. In fact, both weight and body mass index (BMI) are positive predictors of bone mass in adults, suggesting that those who ar...