The Growing Obesity Epidemic and Its Health and Financial Consequences in China

 Over the past three decades, China has enjoyed impressive economic development. Chinese People have experienced many dramatic changes in their lifestyles thanks to the increases in family income and availability of food as a result of China’s economic reform and the growing global trade. People’s lifestyles are becoming increasingly sedentary. Compared to other groups, children and adolescents are likely to be affected to a greater extent by these changes, partially due to China’s ‘one-child policy'.Increasing research including ours suggests that the prevalence of obesity has increased in China both in children and adults. With the increase in obesity, obesity- and diet-related chronic diseases such as hypertension, cerebrovascular disease (CVD), and type 2 diabetes also increased over the past decade and have became the most important preventable cause of death. On the other hand, data collected from pre-school children show that undernutrition remains a public health concern, particularly in poor and rural areas. This article discussed the obesity related issues in China, predominately based on some of our recent research

Childhood Obesity in Minority Populations in the United States

Obesity became a public health crisis in the United States, which affects both adults and children.1,2,24,25 Approximately 31% of U.S. children and adolescents aged 2-19 years were overweight or obese, and almost 17% were obese in 1999-2004.3-5,24 Studies suggest that increased consumption of more energy-dense, nutrient-poor foods with high levels of sugar and saturated fats, combined with reduced physical activity, have contributed to the rising obesity epidemic among children.6,21,28 Childhood obesity increased the risk of many diet-related chronic diseases, including type 2 diabetes, cardiovascular disease, hypertension, stroke, and certain forms of cancers.7 It is important to prevent or control the epidemic across all racial/ethnic groups. However, minority children have a higher prevalence rate of obesity than non-Hispanic white children. This current paper reviews the trends and factors that may contribute to the racial/ethnic disparity

Using Concentration Index to Study Changes in Socio-Economic Inequality of Overweight Among US Adolescents Between 1971 and 2002

Background: The prevalence of overweight among adolescents continues to increase in the United States. This study examines the changes in socio-economic status (SES) inequality of overweight among US adolescents in the past three decades. Methods: Concentration Index (CI) was utilized to measure changes in the SES inequality in prevalence of overweight among US adolescents. Data collected from 15286 adolescents in four waves of the National Health and Nutrition Examination Surveys (NHANES) between 1971 and 2002 and Hispanic Health and Nutrition Examination Survey (HHANES) (1982-84) were used. Results: Changes in the SES inequality of overweight among US adolescents and considerable gender and ethnic differences were detected. For boys, Cl varied from 0.04 in NHANES I to -0.04 in NHANES 1999-2002; for girls, CI varied from -0.12 in NHANES I to -0.18 in NHANES III. Among whites, SES disparity peaked in NHANES III and declined thereafter. Patterns in black and Mexican-American adolescents were mixed. Conclusions: Patterns of SES disparity of overweight among US adolescents varied across ethnic and gender groups, and have changed over time. Disparities have decreased since the early 1990s with the rise of the obesity epidemic. Obesity prevention and management efforts should target all SES groups in the United States

Determination of compactly supported functions in shift-invariant space by single-angle Radon samples

While traditionally the computerized tomography of a function $f\in L^{2}(\mathbb{R}^{2})$ depends on the samples of its Radon transform at multiple angles, the real-time imaging sometimes requires the reconstruction of $f$ by the samples of its Radon transform \mathcal{R}_{\emph{\textbf{p}}}f at a single angle $\theta$, where \emph{\textbf{p}}=(\cos\theta, \sin\theta) is the direction vector. This naturally leads to the question of identifying those functions that can be determined by their Radon samples at a single angle $\theta$. The shift-invariant space $V(\varphi, \mathbb{Z}^2)$ generated by $\varphi$ is a type of function space that has been widely considered in many fields including wavelet analysis and signal processing. In this paper we examine the single-angle reconstruction problem for compactly supported functions $f\in V(\varphi, \mathbb{Z}^2)$. The central issue for the problem is to identify the eligible \emph{\textbf{p}} and sampling set X_{\emph{\textbf{p}}}\subseteq \mathbb{R} such that $f$ can be determined by its single-angle Radon (w.r.t \emph{\textbf{p}}) samples at X_{\emph{\textbf{p}}}. For the general generator $\varphi$, we address the eligible \emph{\textbf{p}} for the two cases: (1) $\varphi$ being nonvanishing (\int_{\mathbb{R}^{2}}\varphi(\emph{\textbf{x}})d\emph{\textbf{x}}\neq0) and (2) being vanishing (\int_{\mathbb{R}^2}\varphi(\emph{\textbf{x}})d\emph{\textbf{x}}=0). We prove that eligible X_{\emph{\textbf{p}}} exists for general $\varphi$. In particular, X_{\emph{\textbf{p}}} can be explicitly constructed if $\varphi\in C^{1}(\mathbb{R}^{2})$. The single-angle problem corresponding to the case that $\varphi$ being positive definite is addressed such that X_{\emph{\textbf{p}}} can be constructed easily

Single-shot phase retrieval: a holography-driven problem in Sobolev space

The phase-shifting digital holography (PSDH) is a widely used approach for recovering signals by their interference (with reference waves) intensity measurements. Such measurements are traditionally from multiple shots (corresponding to multiple reference waves). However, the imaging of dynamic signals requires a single-shot PSDH approach, namely, such an approach depends only on the intensity measurements from the interference with a single reference wave. In this paper, based on the uniform admissibility of plane (or spherical) reference wave and the interference intensity-based approximation to quasi-interference intensity, the nonnegative refinable function is applied to establish the single-shot PSDH in Sobolev space. Our approach is conducted by the intensity measurements from the interference of the signal with a single reference wave. The main results imply that the approximation version from such a single-shot approach converges exponentially to the signal as the level increases. Moreover, like the transport of intensity equation (TIE), our results can be interpreted from the perspective of intensity difference.Comment: 37page