Youfa Wang

Diet Soda Intake and Risk of Incident Metabolic Syndrome and Type 2 Diabetes in the Multi-Ethnic Study of Atherosclerosis (MESA)

OBJECTIVE We determined associations between diet soda consumption and risk of incident metabolic syndrome, its components, and type 2 diabetes in the Multi-Ethnic Study of Atherosclerosis. RESEARCH DESIGN AND METHODS Diet soda consumption was assessed by food frequency questionnaire at baseline (2000–2002). Incident type 2 diabetes was identified at three follow-up examinations (2002–2003, 2004–2005, and 2005–2007) as fasting glucose >126 mg/dl, self-reported type 2 diabetes, or use of diabetes medication. Metabolic syndrome (and components) was defined by National Cholesterol Education Program Adult Treatment Panel III criteria. Hazard ratios (HRs) with 95% CI for type 2 diabetes, metabolic syndrome, and metabolic syndrome components were estimated, adjusting for demographic, lifestyle, and dietary confounders. RESULTS At least daily consumption of diet soda was associated with a 36% greater relative risk of incident metabolic syndrome and a 67% greater relative risk of incident type 2 diabetes compared with nonconsumption (HR 1.36 [95% CI 1.11–1.66] for metabolic syndrome and 1.67 [1.27–2.20] for type 2 diabetes). Of metabolic syndrome components, only high waist circumference (men ≥102 cm and women ≥88 cm) and high fasting glucose (≥100 mg/dl) were prospectively associated with diet soda consumption. Associations between diet soda consumption and type 2 diabetes were independent of baseline measures of adiposity or changes in these measures, whereas associations between diet soda and metabolic syndrome were not independent of these factors. CONCLUSIONS Although these observational data cannot establish causality, consumption of diet soda at least daily was associated with significantly greater risks of select incident metabolic syndrome components and type 2 diabetes.

Changes in racial/ethnic disparities in the prevalence of Type 2 diabetes by obesity level among US adults

Objective. Ethnic minority status and obesity are two independent risk factors for Type 2 diabetes (T2D). There is no clear understanding of how they may have interacted and influenced disparities in T2D prevalence over time. This study examined the trends in racial/ethnic disparities in the prevalence of T2D by weight status among US adults. Methods. We used nationally representative data from the National Health and Nutrition Examination Surveys I (1971–1975), II (1976–1980), and III (1988–1994), and 1999–2004 among 49,574 adults aged 20–74 years. The prevalences of diagnosed and undiagnosed T2D were estimated by race/ethnicity groups (non-Hispanic White, non-Hispanic Black, and Mexican American) and body mass index (BMI) groups (normal, 18.5–24.9; overweight, 25–29.9; obese, 30–34.9; severely obese, ≥35). We used logistic regression controlling for age, gender, and education to estimate the odds ratio of T2D across race/ethnicity and BMI groups. Results. Trends in racial/ethnic disparities in prevalence of diagnosed T2D varied by BMI. Normal weight group saw increasing racial disparities. In the overweight group, ethnic disparities worsened as diabetes prevalence increased 33.3% in Whites, compared to 60.0% in Blacks, and 227.3% in Mexican Americans. Minimal racial/ethnic disparities were observed in obese and severely obese groups over time. In contrast to diagnosed diabetes, overall racial/ethnic disparities in undiagnosed T2D declined in all BMI groups. Conclusions. Racial/ethnic disparities in diabetes prevalence have become most pronounced among normal and overweight groups. Eliminating racial/ethnic disparities in diabetes will require prevention efforts not only in obese minority individuals, but also in normal and overweight minority individuals.

Disparities in Pediatric Obesity in the United States

This paper describes the disparities in the U.S. childhood obesity epidemic, mainly based on recent nationally representative data. The prevalence of overweight and obesity has increased since the late 1970s; the over time shifts (changes) in distributions of various body fatness measures indicate that U.S. children have become fatter and the obese groups gained more body fat, especially more central obesity, as indicated by waist circumference. However, considerable between-group and regional disparities exist in the prevalence, fatness measures, and over time trends. The disparities and trends are complex, which reflects the complexity and dynamics in obesity etiology. Clearly, some population groups are affected more seriously than others. Native American children have the highest prevalence of obesity, whereas Asians have the lowest rate among all ethnic groups. Preschool age children have a lower obesity prevalence than older children. Young people in some states and cities are twice more likely to be overweight or obese than those living in other regions. Low-socioeconomic status is associated with obesity only among some population groups, e.g. white children and adolescents. Vigorous, effective interventions are needed to promote healthy lifestyles among U.S. young people and to reduce disparities in obesity.

Associations between dietary macronutrient intake and plasma lipids demonstrate criterion performance of the Multi-Ethnic Study of Atherosclerosis (MESA) food-frequency questionnaire.

The validity of self-reported dietary intake is critical to the design and interpretation of diet-disease investigations. For many nutrients, there are no ideal methods to establish validity, given correlated error between reference and assessment tools, and constraints on time and resources available to perform such studies. Therefore, we quantified associations between macronutrient intakes and plasma HDL-cholesterol and TAG, relying on known associations between these factors to test the criterion validity of the FFQ used in the Multi-Ethnic Study of Atherosclerosis (MESA). Baseline dietary macronutrient intakes (derived from 120-item FFQ), and fasting plasma HDL and TAG were measured in 4510 MESA participants, aged 45-84 years. After adjusting for non-dietary factors known to affect plasma lipid concentrations, greater carbohydrate intake was associated with lower HDL and higher TAG (beta per 5-unit change in percentage energy intake from carbohydrate = - 5 (se 1) mg/l (P < 0.001) for HDL and 15 (se 6) mg/l (P = 0.008) for TAG), whereas higher energy intake from fat was associated with higher HDL and lower TAG (beta per 5-unit change in percentage energy from fat = 3.7 (se 2) mg/l (P = 0.01) for HDL and beta = 19 (se 7) mg/l (P = 0.004) for TAG). Associations of dietary carbohydrate and fat intakes with HDL and TAG concentrations were consistent with previous studies, demonstrating criterion validity of these dietary measures in the MESA.

Energy balance and obesity: what are the main drivers?

PurposeThe aim of this paper is to review the evidence of the association between energy balance and obesity.MethodsIn December 2015, the International Agency for Research on Cancer (IARC), Lyon, France convened a Working Group of international experts to review the evidence regarding energy balance and obesity, with a focus on Low and Middle Income Countries (LMIC).ResultsThe global epidemic of obesity and the double burden, in LMICs, of malnutrition (coexistence of undernutrition and overnutrition) are both related to poor quality diet and unbalanced energy intake. Dietary patterns consistent with a traditional Mediterranean diet and other measures of diet quality can contribute to long-term weight control. Limiting consumption of sugar-sweetened beverages has a particularly important role in weight control. Genetic factors alone cannot explain the global epidemic of obesity. However, genetic, epigenetic factors and the microbiota could influence individual responses to diet and physical activity.ConclusionEnergy intake that exceeds energy expenditure is the main driver of weight gain. The quality of the diet may exert its effect on energy balance through complex hormonal and neurological pathways that influence satiety and possibly through other mechanisms. The food environment, marketing of unhealthy foods and urbanization, and reduction in sedentary behaviors and physical activity play important roles. Most of the evidence comes from High Income Countries and more research is needed in LMICs.

A Systematic Review of Application and Effectiveness of mHealth Interventions for Obesity and Diabetes Treatment and Self-Management

The use of mobile and wireless technologies and wearable devices for improving health care processes and outcomes (mHealth) is promising for health promotion among patients with chronic diseases such as obesity and diabetes. This study comprehensively examined published mHealth intervention studies for obesity and diabetes treatment and management to assess their effectiveness and provide recommendations for future research. We systematically searched PubMed for mHealth-related studies on diabetes and obesity treatment and management published during 2000-2016. Relevant information was extracted and analyzed. Twenty-four studies met inclusion criteria and varied in terms of sample size, ethnicity, gender, and age of the participating patients and length of follow-up. The mHealth interventions were categorized into 3 types: mobile phone text messaging, wearable or portable monitoring devices, and applications running on smartphones. Primary outcomes included weight loss (an average loss ranging from -1.97 kg in 16 wk to -7.1 kg in 5 wk) or maintenance and blood glucose reduction (an average decrease of glycated hemoglobin ranging from -0.4% in 10 mo to -1.9% in 12 mo); main secondary outcomes included behavior changes and patient perceptions such as self-efficacy and acceptability of the intervention programs. More than 50% of studies reported positive effects of interventions based on primary outcomes. The duration or length of intervention ranged from 1 wk to 24 mo. However, most studies included small samples and short intervention periods and did not use rigorous data collection or analytic approaches. Although some studies suggest that mHealth interventions are effective and promising, most are pilot studies or have limitations in their study designs. There is an essential need for future studies that use larger study samples, longer intervention (≥ 6 mo) and follow-up periods (≥ 6 mo), and integrative and personalized innovative mobile technologies to provide comprehensive and sustainable support for patients and health service providers.

Controversies Regarding Reported Trends: Has the Obesity Epidemic Leveled Off in the United States?

Obesity has become a public health crisis in the United States and many other countries as the prevalence has been growing and has reached a very high level. Many studies have been conducted to examine the trends and related risk factors of obesity. However, some studies provided mixed results. The symposium reviewed the best available evidence regarding the recent trends in the United States and Europe to address the controversies regarding whether the increasing trend has leveled off and to provide some related recommendations. Four leading experts in the field presented key findings and made recommendations for future research and intervention efforts.

Pocket money, eating behaviors, and weight status among Chinese children : The Childhood Obesity Study in China mega-cities

Both the obesity rate and pocket money are rising among children in China. This study examined family correlates of childrens pocket money, associations of pocket money with eating behaviors and weight status, and how the associations may be modified by schools unhealthy food restrictions in urban China. Data were collected in 2015 from 1648 students in 16 primary and middle schools in four mega-cities in China (4 schools/city): Beijing, Shanghai, Nanjing, and Xian. Cluster robust negative binomial regression models were fit to assess family correlates of pocket money, associations of pocket money with child eating behaviors and weight outcomes, and possible modifying effects of schools unhealthy food restrictions. Sixty-nine percent of students received pocket money weekly. Students received more pocket money if mothers frequently ate out of home (IRR=2.28 [1.76, 2.94]) and/or family rarely had dinner together (IRR=1.42, 95%=[1.01, 1.99]). Students got less pocket money if parents were concerned about childs future health due to unhealthy eating (IRR=0.56 [0.32,0.98]). Students with more pocket money more frequently consumed (by 25-89%) sugary beverages, snacks, fast food, or at street food stalls, and were 45-90% more likely to be overweight/obese. Associations of pocket money with unhealthy eating and overweight/obesity were weaker in schools with unhealthy food restrictions. Pocket money is a risk factor for unhealthy eating and obesity in urban China. School policies may buffer pocket moneys negative influence on students eating and weight status.

Applications of geographic information systems (GIS) data and methods in obesity-related research

Geographic information systems (GIS) data/methods offer good promise for public health programs including obesity‐related research. This study systematically examined their applications and identified gaps and limitations in current obesity‐related research. A systematic search of PubMed for studies published before 20 May 2016, utilizing synonyms for GIS in combination with synonyms for obesity as search terms, identified 121 studies that met our inclusion criteria. We found primary applications of GIS data/methods in obesity‐related research included (i) visualization of spatial distribution of obesity and obesity‐related phenomena, and basic obesogenic environmental features, and (ii) construction of advanced obesogenic environmental indicators. We found high spatial heterogeneity in obesity prevalence/risk and obesogenic environmental factors. Also, study design and characteristics varied considerably across studies because of lack of established guidance and protocols in the field, which may also have contributed to the mixed findings about environmental impacts on obesity. Existing findings regarding built environment are more robust than those regarding food environment. Applications of GIS data/methods in obesity research are still limited, and related research faces many challenges. More and better GIS data and more friendly analysis methods are needed to expand future GIS applications in obesity‐related research.

Ethnic Differences in Risk Factors for Obesity among Adults in California, the United States

Little attention has been given to differences in obesity risk factors by racial/ethnic groups. Using data from the 2011-2012 California Health Interview Survey, we examined differences in risk factors for obesity among Whites, Latinos, Asians, and African Americans among 42,935 adults (24.8% obese). Estimates were weighted to ensure an unbiased representation of the Californian population. Multiple logistic and linear regression analyses were used to examine the differences in risk factors for obesity. Large ethnic disparities were found in obesity prevalence: Whites (22.0%), Latinos (33.6%), African Americans (36.1%), and Asians (9.8%). Differences in risk factors for obesity were also observed: Whites (gender, age, physical activity, smoking, arthritis, and diabetes medicine intake), Latinos (age, arthritis, and diabetes medicine intake), Asians (age, binge drinking, arthritis, and diabetes medicine intake), and African Americans (gender, physical activity, smoking, binge drinking, and diabetes medicine intake). Females were more likely to be obese among African Americans (odds ratio (OR) = 1.43, 95% confidence interval (CI) = 1.05–1.94), but less likely among Whites (OR = 0.80, 95% CI = 0.74–0.87). Race/ethnicity should be considered in developing obesity prevention strategies.