Ecological risk model of childhood obesity in Chinese immigrant children

Highlights

• An ecological risk model of obesity in Chinese immigrant children was proposed.

• Various risk factors in five systems within the ecological model were identified.

• The mediating and moderating processes among the risk factors were discussed.

• Use of the ecological model for directing future obesity research was highlighted.

• Chinese immigrant children in the U.S. have been neglected in obesity research.

Abstract

Chinese Americans are the largest and fastest growing Asian American subgroup, increasing about one-third during the 2000s. Despite the slender Asian stereotype, nearly one-third of 6-to-11 year old Chinese American children were found to be overweight (above the 85th percentile in BMI). Importantly, unique and severe health risks are associated with being overweight/obese in Chinese. Unfortunately, Chinese immigrant children have been neglected in the literature on obesity. This review aimed to identify factors at various levels of the ecological model that may place Chinese immigrant children at risk for being overweight/obese in the U.S. Key contextual factors at the micro-, meso-, exo-, macro- and chronosystem were identified guided by Bronfenbrenner's ecological systems theory. The corresponding mediating and moderating processes among the factors were also reviewed and proposed. By presenting a conceptual framework and relevant research, this review can provide a basic framework for directing future interdisciplinary research in seeking solutions to childhood obesity within this understudied population.

Introduction

Childhood obesity is a critical public health threat in the U.S. (Skinner & Skelton, 2014). Over the past three decades, the childhood obesity rate has doubled for preschool children aged 2–5 years and tripled for children aged 6–11 years in the U.S. (Institute of Medicine of the National Academies, 2005). Moreover, more severe forms of childhood obesity (i.e., class 2 and 3 obesity) have increased over the last 14 years (Skinner & Skelton, 2014). Childhood obesity has both immediate and long-term risks to children's physical health, such as Type 2 diabetes, high cholesterol, metabolic syndrome, and sleep apnea (National Institutes of Health, National Heart, Lung, and Blood Institute, 2010). Children who are obese also suffer socioemotional health problems (e.g., low self-esteem, social marginalization) leading to poor academic and social adjustment (Harrist et al, 2012, Strauss, Pollack, 2003).

Chinese Americans are the largest and fastest growing Asian American subgroup, increasing about one-third during the 2000s (Hoeffel, Rastogi, Kim, & Shahid, 2012). Children of immigrants in the U.S. appear to be at higher risk of being overweight than their non-immigrant counterparts (Baker et al, 2009, Balistreri, Van Hook, 2009). Despite the slender Asian stereotype, 23.5% of 4-year old Chinese American children were found to be at risk of being overweight or obese in a nationally representative sample (Jain et al., 2012) and nearly one-third of 6-to-11 year old Chinese American children were reported to be overweight or obese (Au et al, 2009, Chen, Kennedy, 2005).

In addition, Chinese individuals carry higher health risks of being overweight or obese compared to their counterparts of European descents (Razak et al., 2007). Chinese individuals with the same BMI as Whites have higher percentage body fat and are at a higher risk of developing chronic diseases, cardiovascular disease, and Type 2 diabetes mellitus, possibly because of genetic differences in body composition, metabolic responses, and epigenetic factors (e.g., Pan et al, 2004, Razak et al, 2007). Despite their rapid population growth, increasing obesity prevalence, and the severe health consequences of being overweight in this population, Chinese immigrant children have been neglected in the literature on obesity.

Although there are important biological predispositional causes of obesity that require continued attention, emerging research suggests that a transdisciplinary understanding of obesity through an ecological perspective is also needed (Harrist et al., 2012). Bronfenbrenner's (1979) ecological model of human development has guided developmental researchers for decades in understanding the contributions of the environment from the perspective of the developing person within a set of nested and intertwined structures, including the microsystem, mesosystem, exosystem, macrosystem, and chronosystem (see Fig. 1). This ecological model also highlights the complex reciprocal interactions between the active developing person and his/her immediate environment, referred as proximal processes, in which development takes place (Bronfenbrenner, 1994). Also, distal processes are included, such as families' ability to interact with their environment and utilize resources, which indirectly impact children's risk for obesity. Moreover, given that children's obesity is associated with nutrition and diet, physical activity, and personal and relational attributes, this review identifies and discusses key factors reflecting these attributes at various levels of the ecological model (Harrison et al, 2011, Neumark-Sztainer, 2005). With the rates of childhood obesity at their highest point in the history, it is imperative to understand the risk factors in Chinese immigrant children's ecological context to guide future prevention and intervention efforts that might be more culturally appropriate and effective in preventing obesity and promoting healthy behaviors.

In this review, Chinese immigrant children refer to children who are born to foreign-born first-generation immigrant parents of Chinese descent. These children include both foreign-born (first-generation and/or 1.5 generation) and U.S. born (second-generation) individuals (Garcia Coll & Marks, 2012). Due to the limited research on these topics among Chinese immigrant families, we reviewed relevant research from other immigrant groups or individuals of Asian descent, when appropriate. In some cases, findings from studies conducted on non-immigrant or non-Asian descent will also be presented in highlighting important processes that might be relevant for Chinese immigrant groups. This review was not intended to be exhaustive in its identification of risk factors or in the research reviewed. Instead, specific key characteristics in each system of the ecological model were identified and discussed. Moreover, the mediating or moderating linkages among these characteristics were proposed from an ecological perspective, in determining possible maladaptive processes, which may put Chinese immigrant children at risk of being overweight or obese. Overall, the full ecological model involves a view of the development of childhood obesity as influenced by specific risk characteristics in the child and families as well as the mediating and moderating processes among these factors at different system levels. By presenting a conceptual framework and relevant research, this review can provide a basic foundation for directing future interdisciplinary research in seeking solutions to childhood obesity within this understudied population.