The Effects of Physical Activity and Sedentary Behaviors on Overweight and Obesity among Boys may Differ from those among Girls in China: An Open Cohort Study.

BACKGROUND: Childhood overweight and obesity are increasing steadily in China, yet few studies have focused on exploring the risk factors associated with sex differences. OBJECTIVES: We tested the hypothesis that the effects of physical activity and sedentary behaviors on overweight and obesity differ between boys and girls. METHODS: We used data collected from 4520 children and adolescents aged 6-18 y from 2004 to 2015 in an ongoing open-cohort study, the China Health and Nutrition Survey, to explore the effects of physical activity and sedentary behaviors on the risk of overweight and obesity in Chinese children and adolescents. We collected detailed information on physical activity and sedentary behavior along with dietary data, and we measured height and weight with standardized methods. We used random-effects logistic regression models to analyze the associations between total physical activity and sedentary behavior and overweight and obesity. RESULTS: The effects of sedentary behaviors and vigorous physical activity were only significant among girls. Vigorous physical activity decreased the risk of overweight and obesity by 63% (OR: 0.37; 95% CI: 0.20, 0.67) among girls ages 6-11 y and by 54% (OR: 0.46; 95% CI: 0.25, 0.85) among girls ages 12-18 y. High sedentary-hour values increased the risk by 96% (OR: 1.96; 95% CI: 1.09, 3.54) among girls ages 12-18 y. None of the effects were significant among boys. CONCLUSION: Low physical activity and high sedentary time increase the risk of overweight and obesity, particularly among adolescent girls. The effects of physical activity and sedentary behaviors on overweight and obesity among boys may differ from those among girls. Sex effects should be taken into consideration when promoting physical activity. Whether this sex difference is a result of high male preferences in China that preclude many activities among boys or other factors requires further study.

Changes in nonnutritive sweetener intake in a cohort of preschoolers after the implementation of Chile's Law of Food Labelling and Advertising.

BACKGROUND: The first phase of Chile's Law of Food Labelling and Advertising showed important declines in the sugar content of packaged foods, but it is unknown whether the law led to an increase in nonnutritive sweetener (NNS) intake, particularly among preschool children. OBJECTIVES: Estimate the changes in preschoolers' NNS intake after the first phase of the Chilean law. METHODS: We used 24-h dietary recalls collected in 2016 (pre-law) and 2017 (post-law) from a cohort of preschoolers (n = 875). The primary caretaker was the respondent of the recalls. Information on NNS was obtained from nutrition facts panels collected annually and linked to dietary data. We used logistic regression to estimate the changes in the proportion of preschoolers who consume NNS and two-part models to estimate the changes in mean intake. We determined the percentage of children that surpassed the acceptable daily intake (ADI) of each NNS using the National Cancer Institute method. RESULTS: The proportion of consumers of at least one NNS increased from 77.9% to 92.0% (p-value < 0.01). The mean intake increased for sucralose, aspartame, acesulfame-K and steviol glycosides (+20.3, +15.1, +6.1 and +3.3 mg/day, respectively). In addition, NNS dietary sources changed for sucralose and steviol glycosides, becoming industrialized juices and dairy beverages more relevant while tabletop NNS became less relevant. None of the children surpassed the ADI. CONCLUSIONS: NNS intake increased in preschoolers after the first phase of a national policy that promoted sugar reformulation.

Equitability of Individual and Population Interventions to Reduce Obesity: A Modeling Study in Mexico.

INTRODUCTION: Modeling studies have estimated the potential impact and cost effectiveness of interventions to reduce obesity; few have focused on their equity across socioeconomic groups. This study aims to compare the equitability of individual- and population-level interventions to reduce obesity in Mexico. METHODS: Mathematical models were implemented to estimate the expected effect of 2 sugar-sweetened beverage tax scenarios (10% and 20%) and bariatric surgery, pharmacotherapy, and dietary advice as individual interventions to reduce body weight. Individual interventions were modeled using meta-analytical weight change, inclusion and exclusion criteria, and the probability of access to healthcare services. For the tax, investigators obtained the baseline consumption of sugar-sweetened beverages from the National Health Survey 2012 and applied the reduction in sales observed in 2016 to estimate the caloric change and weight reduction. Implementation costs and cost per person, per kilogram, and equity were calculated for all interventions over a 1-year timeframe. RESULTS: The 20% tax produced the largest estimated increase (4.50%) in normal BMI prevalence, was the most cost effective, and had the largest and most equitable decrease in obesity across socioeconomic categories. Pharmacotherapy and bariatric surgery produced sizable decreases in obesity prevalence (3.68% and 1.18%), particularly among the middle and high socioeconomic groups, whereas dietary advice had the lowest impact on normal and obese categories. CONCLUSIONS: Individual interventions were effective in reducing obesity; yet, they were more expensive and less equitable than population interventions. Obesity in Mexico affects all socioeconomic groups; available interventions need to be carefully analyzed to tailor a national strategy that is both effective and equitable.

Soft drink intake is associated with weight gain, regardless of physical activity levels: the health workers cohort study.

BACKGROUND: While soft drink intake is positively associated with weight gain, no previous study has investigated whether leisure-time physical activity modifies this association. We estimated the association between soft drink intake and body weight, and explored if this association differed by levels of leisure-time physical activity. METHODS: We used data from the health workers cohort study, a prospective study of Mexican adults (20 to 85y old), including 1268 health workers and their families, who were assessed at baseline (2004-2006) and follow-up (2010-2012). We assessed soft drink intake (cola and flavored soda) using a validated food frequency questionnaire. We measured leisure-time physical activity using a self-report questionnaire, and categorized according to the 2010 World Health Organization (WHO) recommendations. Body weight was measured by trained personnel. The association between changes in soft drink intake and weight change, and if such association varied by levels of physical activity was estimated through fixed-effect models. RESULTS: An increase in one serving per day of soft drink was associated with 0.10 kg (95% CI 0.00, 0.19) increase in weight per year. This association was not modified by leisure-time physical activity, as demonstrated by the magnitude of the coefficient of the interaction between soft drink, leisure-time physical activity, and time (- 0.03 kg, 95% CI - 0.27 to 0.21); people who complied with the WHO physical activity recommendations gained 0.36 kg/year per serving of soft drink, compared to 0.48 kg/year for people without sufficient physical activity. CONCLUSIONS: Soft drink intake was associated with weight gain. Leisure-time physical activity did not modify the association between soft drink intake and weight gain. This finding challenges the idea that leisure-time physical activity is sufficient to counterbalance weight gain associated to soft drink intake.

Cross-sectional association between diet quality and cardiometabolic risk by education level in Mexican adults.

OBJECTIVE: Understanding the association between diet quality and cardiometabolic risk by education level is important for preventing increased cardiometabolic risk in the Mexican population, especially considering pre-existing disparities in diet quality. The present study examined the cross-sectional association of overall diet quality with cardiometabolic risk, overall and by education level, among Mexican men and women. DESIGN: Cardiometabolic risk was defined by using biomarkers and diet quality by the Mexican Diet Quality Index. We computed sex-specific multivariable logistic regression models. SETTING: Mexico. PARTICIPANTS: Mexican men (n 634) and women (n 875) participating in the Mexican National Health and Nutrition Survey 2012. RESULTS: We did not find associations of diet quality with cardiometabolic risk factors in the total sample or in men by education level. However, we observed that for each 10-unit increase in the dietary quality score, the odds of diabetes risk in women with no reading/writing skills was 0·47 (95 % CI 0·26, 0·85) relative to the odds in women with ≥10 years of school (referent). Similarly, for each 10-unit increase of the dietary quality score, the odds of having three v. no lipid biomarker level beyond the risk threshold in lower-educated women was 0·27 (95 % CI 0·12, 0·63) relative to the odds in higher-educated women. CONCLUSIONS: Diet quality has a stronger protective association with some cardiometabolic disease risk factors for lower- than higher-educated Mexican women, but no association with cardiometabolic disease risk factors among men. Future research will be needed to understand what diet factors could be influencing the cardiometabolic disease risk disparities in this population.

Causal Language in Health Warning Labels and US Adults' Perception: A Randomized Experiment.

Objectives. To examine US adults' reactions to health warnings with strong versus weak causal language.Methods. In 2018, we randomly assigned 1360 US adults to answer an online survey about health warnings for cigarettes, sugar-sweetened beverages, or alcohol. Participants rated 4 warning statements using different causal language variants ("causes," "contributes to," "can contribute to," and "may contribute to") displayed in random arrangement.Results. Most participants (76.3%) selected the warning that used "causes" as the 1 that most discouraged them from wanting to use the product. "Causes" was also selected most often (39.0% of participants) as the warning that participants most supported implementing. By contrast, most (66.1%) chose "may contribute to" as the warning that least discouraged them from wanting to use the product. We found few demographic differences in these patterns.Conclusions. Warnings with stronger causal language are perceived to be effective and are supported by the public.

The association of overall diet quality with BMI and waist circumference by education level in Mexican men and women.

OBJECTIVE: The present study evaluated the association of two measures of diet quality with BMI and waist circumference (WC), overall and by education level, among Mexican men and women. DESIGN: We constructed two a priori indices of diet quality, the Mexican Diet Quality Index (MxDQI) and the Mexican Alternate Healthy Eating Index (MxAHEI), which we examined relative to BMI and WC. We computed sex-specific multivariable linear regression models for the total sample and by education level. SETTING: Mexico. PARTICIPANTS: Mexican men (n 954) and women (n 1356) participating in the Mexican National Health and Nutrition Survey 2012. RESULTS: Total dietary scores were not associated with BMI in men and women, but total MxDQI was inversely associated with WC in men (-0·10, 95 % CI -0·20, -0·004 cm). We also found that some results differed by education level in men. For men with the lowest education level, a one-unit increase in total MxDQI and MxAHEI score was associated with a mean reduction in BMI of 0·11 (95 % CI -0·18, 0·04) and 0·18 (95 % CI -0·25, -0·10) kg/m2, respectively. Likewise, a one-unit increase in total MxDQI and MxAHEI score was associated with a mean change in WC of -0·30 (95 % CI -0·49, -0·11) and -0·53 (95 % CI -0·75, -0·30) cm, respectively, in men with the lowest level of education. In women, the association of diet quality scores with BMI and WC was not different by education level. CONCLUSIONS: Our findings suggest that a higher diet quality in men with low but not high education is associated with lower BMI and WC.

Persistent disparities over time in the distribution of sugar-sweetened beverage intake among children in the United States.

Background: Recent research suggests that sugar-sweetened beverage (SSB) consumption has been declining among US children aged 2-18 y. However, most studies focused on changes in mean intake, ignore high SSB consumers and do not examine intake among vulnerable groups and, including adolescents, low-income households, and several racial/ethnic minorities. Objective: The aim was to estimate usual SSB intake from NHANES surveys from 2003-2004 to 2013-2014 to examine shifts at both the median and 90th percentile among US children, evaluating the extent to which intake disparities in total SSBs and subtypes have persisted. Design: Children 2-18 y from NHANES 2003, 2005, 2007, 2009, 2011 and 2013. SSBs were all non-diet beverages sweetened with sugars including revising all beverages to as consumed status and excluding soy and dairy based beverages. The NCI usual intake method was used to estimate usual intake from two 24-hour recalls. A 2-part correlated model accounted for nonconsumers. Quantile regression was then used to examine differences in SSB usual intakes at the 50th and 90th percentiles by race-ethnicity, and examine interactions indicating whether racial-ethnic disparities in intake were modified by income. Results: Despite considerable declines, children's SSB intake remains high, particularly among heavy consumers. Among adolescents, median SSB intake in 2013-2014 was on the order of 150-200 kcal/d, and heavy intake at the 90th percentile was on the order of 250-300 kcal/d. There were important disparities in intake that persisted over time. Although high household income was associated with lower SSB intake in non-Hispanic white (NHW) children, intakes of non-Hispanic black (NHB) and Mexican-American (MA) children from these households were similar to or higher than those from poor households. There were also large racial/ethnic differences in the types of SSBs consumed. The consumption of regular sodas by NHB children was somewhat lower than among MA and NHW children, whereas fruit drink intake was markedly higher. Conclusions: Overall, these findings suggest that, despite recent declines, strategies are needed to further reduce SSB consumption, and particularly heavy intake, especially among NHB children where fruit drinks also are key source of SSBs.

Equity impacts of price policies to promote healthy behaviours.

Governments can use fiscal policies to regulate the prices and consumption of potentially unhealthy products. However, policies aimed at reducing consumption by increasing prices, for example by taxation, might impose an unfair financial burden on low-income households. We used data from household expenditure surveys to estimate patterns of expenditure on potentially unhealthy products by socioeconomic status, with a primary focus on low-income and middle-income countries. Price policies affect the consumption and expenditure of a larger number of high-income households than low-income households, and any resulting price increases tend to be financed disproportionately by high-income households. As a share of all household consumption, however, price increases are often a larger financial burden for low-income households than for high-income households, most consistently in the case of tobacco, depending on how much consumption decreases in response to increased prices. Large health benefits often accrue to individual low-income consumers because of their strong response to price changes. The potentially larger financial burden on low-income households created by taxation could be mitigated by a pro-poor use of the generated tax revenues.

Understanding bias in relationships between the food environment and diet quality: the Coronary Artery Risk Development in Young Adults (CARDIA) study.

BACKGROUND: The relationship between food environment exposures and diet behaviours is unclear, possibly because the majority of studies ignore potential residual confounding. METHODS: We used 20 years (1985-1986, 1992-1993 2005-2006) of data from the Coronary Artery Risk Development in Young Adults (CARDIA) study across four US cities (Birmingham, Alabama; Chicago, Illinois; Minneapolis, Minnesota; Oakland, California) and instrumental variables (IV) regression to obtain causal estimates of longitudinal associations between the percentage of neighbourhood food outlets (per total food outlets within 1 km network distance of respondent residence) and an a priori diet quality score, with higher scores indicating higher diet quality. To assess the presence and magnitude of bias related to residual confounding, we compared results from causal models (IV regression) to non-causal models, including ordinary least squares regression, which does not account for residual confounding at all and fixed-effects regression, which only controls for time-invariant unmeasured characteristics. RESULTS: The mean diet quality score across follow-up was 63.4 (SD=12.7). A 10% increase in fast food restaurants (relative to full-service restaurants) was associated with a lower diet quality score over time using IV regression (ß=-1.01, 95% CI -1.99 to -0.04); estimates were attenuated using non-causal models. The percentage of neighbourhood convenience and grocery stores (relative to supermarkets) was not associated with diet quality in any model, but estimates from non-causal models were similarly attenuated compared with causal models. CONCLUSION: Ignoring residual confounding may generate biased estimated effects of neighbourhood food outlets on diet outcomes and may have contributed to weak findings in the food environment literature.

Trends in domain-specific physical activity and sedentary behaviors among Chinese school children, 2004-2011.

BACKGROUND: Dramatic increases in child overweight have occurred in China. A comprehensive look at trends in physical activity and sedentary behaviors among Chinese youth is needed. The study aimed to examine trends in domain-specific physical activity and sedentary behaviors, explore mean and distributional changes in predicted behaviors over time, and investigate how behaviors vary by residence. METHODS: Using 2004-2011 China Health and Nutrition Survey data, adjusted means for MET-hours/week from physical activity and hours/week from sedentary behaviors were determined for school children (6-18 years), stratifying by gender, age group, and residence. Physical activity domains included in-school physical activity, active leisure (out-of-school physical activity), active travel (walking or biking), and domestic activity (cooking, cleaning, and child care). For each physical activity domain, the MET-hours/week measure was determined from the total weekly time spent (hours) in domain-specific activities and corresponding MET-values using the Compendium of Energy Expenditures for Youth. Sedentary behaviors included television, computer use, homework, and other behaviors (board games, toys, extracurricular reading and writing). For each sedentary behavior, the hours/week measure was determined from total weekly time spent in specific sedentary behaviors. Residence groups included megacities (population ≥ 20million), cities/towns (300,000 ≤ population < 20million), and rural/suburban areas (population < 300,000). Repeated measure linear mixed and quantile regression models were used to predict adjusted means. RESULTS: Little change in physical activity behaviors occurred over time, with the exception of statistically significant trends toward increased domestic activity among male children (p < .05). Across all gender and age groups, statistically significant trends over time toward an average increase in computer use were seen (p < .01); these increases were largely driven by those ≥50th percentile on the distribution. Children living in megacities (versus rural areas) reported higher levels of physical activity, homework, and computer use. CONCLUSIONS: Intensified, systematic intervention and policy efforts promoting physical activity and reducing sedentary behaviors among children are needed.

Longitudinal associations of away-from-home eating, snacking, screen time, and physical activity behaviors with cardiometabolic risk factors among Chinese children and their parents.

Background: Little is known about intergenerational differences in associations of urbanization-related lifestyle behaviors with cardiometabolic risk factors in children and their parents in rapidly urbanizing China.Objective: We tested the intergenerational differences in longitudinal associations of away-from-home eating, snacking, screen time, and leisure-time sports with high waist-to-height ratio (WHtR), elevated blood pressure (BP), elevated glycated hemoglobin (HbA1c), and elevated C-reactive protein (CRP) among Chinese children and their parents.Design: We studied children enrolled in the longitudinal China Health and Nutrition Survey (1991-2009, 7 surveys) aged 7-17 y in ≥2 surveys (average follow-up: 2.3 surveys out of a possible 4 surveys with the age restriction; n = 3875, including 1175 siblings) and their parents (2947 mothers, 2632 fathers) living in the same household. We used 3 consecutive interviewer-administered 24-h dietary recalls to derive a 3-d average for away-from-home eating (nonconsumer, >0 and <1 meal/d, or ≥1 meals/d) and consumption of fruit or vegetable snacks (any or none) and other snacks (any or none) and a self-reported 7-d physical activity recall for screen time (≤1, >1 and ≤2, or >2 h/d) and leisure-time sports (any or none). Random-effects logistic regression was used to examine the associations of lagged (average: 3 y) behaviors with cardiometabolic risk factors (WHtR, BP, HbA1c, and CRP).Results: We detected intergenerational differences in associations between lagged behaviors and risk factors (P-interaction < 0.1). Generation-specific models showed that lagged away-from-home eating of ≥1 meal/d (compared with none) was negatively associated with parents' high WHtR (OR: 0.68; 95% CI: 0.53, 0.88) but positively associated with children's high WHtR (OR: 1.46; 95% CI: 1.01, 2.12). Lagged fruit and vegetable snack consumption was negatively related to parents' (OR: 0.76; 95% CI: 0.59, 0.97) and children's (OR: 0.58; 95% CI: 0.33, 1.00) high WHtR. Lagged screen time (>2 compared with ≤1 h/d) was positively associated with parents' (OR: 2.58; 95% CI: 1.56, 4.28) and children's high WHtR (OR: 2.26; 95% CI: 1.06, 4.83).Conclusion: Parent-offspring differences in associations between lifestyle behaviors and cardiometabolic risk factors provide insight into intergenerational differences in cardiometabolic risk with urbanization.

Parent-child associations for changes in diet, screen time, and physical activity across two decades in modernizing China: China Health and Nutrition Survey 1991-2009.

BACKGROUND: While the household context is important for lifestyle behavior interventions, few studies have examined parent-child associations for diet and physical activity (PA) changes over time in a rapidly urbanizing country. We aimed to investigate changes in diet, screen time, and PA behaviors over time in children and their parents living in the same household, and examine the parent-child association for these behaviors. METHODS: We studied dietary, screen time, and PA behaviors in 5,201 parent-child pairs (children aged 7-17y) using longitudinal data from the China Health and Nutrition Survey (1991, 1993, 1997, 2000, 2004, 2006, and 2009). We collected three-day 24-h recall diet data to generate percentages of energy from animal-source foods, away-from-home eating, and snacking from 1991-2009, which are known urbanization-related behaviors. We used a seven-day PA recall to collect screen time (hours/week) and leisure-time sports participation (yes/no) since 2004. We examined the changes in children's and parents' behaviors over time using random-effects negative binomial regression for diet and screen time, and random-effects logistic regression for leisure-time sports. We then regressed each of the behaviors of offspring on each of their parents' same behaviors to examine the parent-child association, using the same set of models. RESULTS: We observed increases in energy from animal-source foods, eating away-from-home, and snacking, as well as screen time and leisure-time sports in parents and children over time, with different rates of change between children and their parents for some behaviors. We found positive parent-child associations for diet, screen time, and PA. When parental intakes increased by 10 % energy from each dietary behavior, children's increase in intakes ranged from 0.44 to 1.59 % total energy for animal-source foods, 0.17 % to 0.45 % for away-from-home eating, and 2.13 % to 7.21 % for snacking. Children were also more likely to participate in leisure-time sports if their parents participated in leisure-time sports. CONCLUSION: Our findings support household-based health behavior interventions targeting both children and their parents. However, generation-specific intervention strategies may be needed for children and adults, especially for dietary behaviors, which changed differentially in children versus parents in this rapidly modernizing population.

Instrumental-Variables Simultaneous Equations Model of Physical Activity and Body Mass Index: The Coronary Artery Risk Development in Young Adults (CARDIA) Study.

We used full-system-estimation instrumental-variables simultaneous equations modeling (IV-SEM) to examine physical activity relative to body mass index (BMI; weight (kg)/height (m)(2)) using 25 years of data (1985/1986 to 2010/2011) from the Coronary Artery Risk Development in Young Adults (CARDIA) Study (n = 5,115; ages 18-30 years at enrollment). Neighborhood environment and sociodemographic instruments were used to characterize physical activity, fast-food consumption, smoking, alcohol consumption, marriage, and childbearing (women) and to predict BMI using semiparametric full-information maximum likelihood estimation to control for unobserved time-invariant and time-varying residual confounding and differential measurement error through model-derived discrete random effects. Comparing robust-variance ordinary least squares, random-effects regression, fixed-effects regression, single-equation-estimation IV-SEM, and full-system-estimation IV-SEM, estimates from random- and fixed-effects models and the full-system-estimation IV-SEM were unexpectedly similar, despite the lack of control for residual confounding with the random-effects estimator. Ordinary least squares tended to overstate the significance of health behaviors in BMI, while results from single-equation-estimation IV-SEM were notably different, revealing the impact of weak instruments in standard instrumental-variable methods. Our robust findings for fixed effects (which does not require instruments but has a high cost in lost degrees of freedom) and full-system-estimation IV-SEM (vs. standard IV-SEM) demonstrate potential for a full-system-estimation IV-SEM method even with weak instruments.

Estimating usual intakes mainly affects the micronutrient distribution among infants, toddlers and pre-schoolers from the 2012 Mexican National Health and Nutrition Survey.

OBJECTIVE: To compare estimates from one day with usual intake estimates to evaluate how the adjustment for within-person variability affected nutrient intake and adequacy in Mexican children. DESIGN: In order to obtain usual nutrient intakes, the National Cancer Institute's method was used to correct the first 24 h dietary recall collected in the entire sample (n 2045) with a second 24 h recall collected in a sub-sample (n 178). We computed estimates of one-day and usual intakes of total energy, fat, Fe, Zn and Na. SETTING: 2012 Mexican National Health and Nutrition Survey. SUBJECTS: A total of 2045 children were included: 0-5·9 months old (n 182), 6-11·9 months old (n 228), 12-23·9 months old (n 537) and 24-47·9 months old (n 1098). From these, 178 provided an additional dietary recall. RESULTS: Although we found small or no differences in energy intake (kJ/d and kcal/d) between one-day v. usual intake means, the prevalence of inadequate and excessive energy intake decreased somewhat when using measures of usual intake relative to one day. Mean fat intake (g/d) was not different between one-day and usual intake among children >6 months old, but the prevalence of inadequate and excessive fat intake was overestimated among toddlers and pre-schoolers when using one-day intake (P6 months. CONCLUSIONS: There was overall low variability in energy and fat intakes but higher for micronutrients. Because the usual intake distributions are narrower, the prevalence of inadequate/excessive intakes may be biased when estimating nutrient adequacy if one day of data is used.

Differential associations of urbanicity and income with physical activity in adults in urbanizing China: findings from the population-based China Health and Nutrition Survey 1991-2009.

BACKGROUND: High urbanicity and income are risk factors for cardiovascular-related chronic diseases in low- and middle-income countries, perhaps due to low physical activity (PA) in urban, high income areas. Few studies have examined differences in PA over time according to income and urbanicity in a country experiencing rapid urbanization. METHODS: We used data from the China Health and Nutrition Survey, a population-based cohort of Chinese adults (n = 20,083; ages 18-75y) seen a maximum of 7 times from 1991-2009. We used sex-stratified, zero-inflated negative binomial regression models to examine occupational, domestic, leisure, travel, and total PA in Chinese adults according to year, urbanicity, income, and the interactions among urbanicity, income, and year, controlling for age and region of China. RESULTS: We showed larger mean temporal PA declines for individuals living in relatively low urbanicity areas (1991: 500 MET-hours/week; 2009: 300 MET-hours/week) compared to high urbanicity areas (1991: 200 MET-hours/week; 2009: 125 MET-hours/week). In low urbanicity areas, the association between income and total PA went from negative in 1991 (p < 0.05) to positive by 2000 (p < 0.05). In relatively high urbanicity areas, the income-PA relationship was positive at all time points and was statistically significant at most time points after 1997 (p < 0.05). Leisure PA was the only domain of PA that increased over time, but >95% of individuals in low urbanicity areas reported zero leisure PA at each time point. CONCLUSIONS: Our findings show changing associations for income and urbanicity with PA over 18 years of urbanization. Total PA was lower for individuals living in more versus less urban areas at all time points. However, these differences narrowed over time, which may relate to increases in individual-level income in less urban areas of China with urbanization. Low-income individuals in higher urbanicity areas are a particularly critical group to target to increase PA in China.

A Water and Education Provision Intervention Modifies the Diet in Overweight Mexican Women in a Randomized Controlled Trial.

BACKGROUND: There is minimal information on the impact of replacing sugar-sweetened beverage (SSB) consumption with water on diet quality from randomized controlled trials. OBJECTIVE: We evaluated the effect of a water intake intervention on diet quality in overweight Mexican women. METHODS: Women with a body mass index ≥25 and <39, 18-45 y old, and a self-reported high intake of SSBs (≥250 kcal/d) were randomly allocated to either the water and education provision (WEP) group (n = 120) or the education provision (EP) only group (n = 120). Each group received monthly nutrition counseling, and the WEP group received biweekly water deliveries for 9 mo. Three 24-h recalls, anthropometry, and demographic information were collected at baseline, and 3, 6, and 9 mo. Energy, macronutrient, sugar, SSB, fruit and vegetable, salty snack, cake and cookie, and fast food intakes were assessed in study completers (n = 189) classified by intervention assignment and by actual water intake at every time point (low <1200 vs. high ≥1200 mL/d). RESULTS: The WEP group reported greater decreases in SSB intake than the EP group (from 20.9% to 10.3% of energy/d vs. from 20.1% to 17.8%). Thirty-eight percent of the EP group and 84.3% of the WEP group reported attaining a water intake ≥1200 mL/d. Reductions in energy intake and food groups were similar across intervention groups. However, the high actual water intake group reported greater increases vs. the lower intake group in intake of fruits and vegetables (117 vs. 47 g/d), as well as larger reductions in salty snacks (4.6 vs. 0.7 g/d) and cakes and cookies (31.7 vs. 14.7 g/d). CONCLUSIONS: Other than SSBs, improvements in food group intake did not differ by intervention group in overweight Mexican women. However, post hoc analyses suggested that achieving a high actual water intake was associated with additional beneficial changes in food group intake. This trial was registered at clinicaltrials.gov as NCT01245010.

White Rice Intake Varies in Its Association with Metabolic Markers of Diabetes and Dyslipidemia Across Region among Chinese Adults.

BACKGROUND/AIMS: There are inconsistent associations between white rice consumption and diabetes and dyslipidemia, perhaps due to the nature of samples studied and quality of diet data. METHODS: Using regionally diverse data from adults enrolled in the China Health and Nutrition Survey (n = 7,878) with diet data from three repeated 24-hour recalls and fasting blood to derive diabetes and dyslipidemia, we examined the odds of diabetes and dyslipidemia in participants across region-specific tertiles of percent energy from white rice consumption. RESULTS: The prevalence of undiagnosed diabetes, high triglycerides, high low-density lipoprotein (LDL), low high-density lipoprotein (HDL), and atherogenic dyslipidemia (AD) was 4.7%, 31.8%, 31.3%, 25.9%, and 14.6%, respectively. We found an inverse association between the highest (versus lowest) tertile of rice intake and diabetes in Central China (odds ratio (OR): 0.59, 95% confidence interval (CI): 0.36-0.99). The highest rice consumption was also associated with high triglycerides (OR: 1.46, 95% CI: 1.09-1.95), low HDL (OR: 1.38, 95% CI: 1.03-1.85), and AD (OR: 1.63, 95% CI: 1.15-2.31) in North China, and low LDL (OR: 0.54, 95% CI: 0.42-0.69) in Central China. CONCLUSIONS: The association between white rice consumption and diabetes and dyslipidemia markers varied across regions of China, suggesting a role of other dietary and health-related exposures, beyond rice.

Variant Near FGF5 Has Stronger Effects on Blood Pressure in Chinese With a Higher Body Mass Index.

BACKGROUND: The objective of this study was to investigate the genetic association of 4 candidate variants with blood pressure and test the modifying effects of environmental factors including age, sex, and body mass index (BMI). METHODS: We used a linear mixed-effects model to test for variant main effects and variant interactions with age, sex, and BMI on systolic (SBP) and diastolic (DBP) blood pressure in 7,319 Chinese adults from the China Health and Nutrition Survey (CHNS). We attempted to replicate our significant interaction findings in 1,996 Chinese men from the Fangchenggang Area Male Health and Examination Survey (FAMHES). RESULTS: Two variants (rs11105378 near ATP2B1 and rs1458038 near FGF5) were significantly associated (P < 0.00625 = 0.05/8) with both SBP and DBP in CHNS. Variant rs1378942 near CSK was nominally associated with SBP (P = 0.01). The signal at rs1458038 exhibited a genotype-by-BMI interaction affecting blood pressure (P interaction = 0.0018 for SBP; P interaction = 0.049 for DBP), with the strongest variant effects in those with the highest BMI. In FAMHES, rs1458038 also showed stronger effects on SBP and DBP among men with the highest BMI. CONCLUSIONS: Our findings suggest high BMI increases the effect of the blood pressure-increasing allele at rs1458038 near FGF5, further highlighting the importance of obesity prevention in reducing hypertension risk.

Eighteen year weight trajectories and metabolic markers of diabetes in modernising China.

AIMS/HYPOTHESIS: Although obesity is a major risk factor for diabetes, little is known about weight gain trajectories across adulthood, and whether they are differentially associated with metabolic markers of diabetes. METHODS: We used fasting blood samples and longitudinal weight data for 5,436 adults (5,734 observations, aged 18-66 years) from the China Health and Nutrition Survey (1991-2009). Using latent class trajectory analysis, we identified different weight gain trajectories in six age and sex strata, and used multivariable general linear mixed effects models to assess elevated metabolic markers of diabetes (fasting glucose, HbA1c, HOMA-IR, insulin) across weight trajectory classes. Models were fitted within age and sex strata, and controlled for baseline weight (or baseline weight by weight trajectory interaction terms), height, and smoking habit, with random intercepts to control for community-level correlations. RESULTS: Compared with weight gain, classes with weight maintenance, weight loss, or a switch from weight gain to loss had lower values for metabolic markers of diabetes. These associations were stronger among younger women (aged 18-29 and 30-39 years) and men (18-29 years) than in older (40-66 years) men and women. An exception was HOMA-IR, which showed class differences across all ages (at least p < 0.004). CONCLUSION: Trajectory analysis identified heterogeneity in adult weight gain associated with diabetes-related metabolic markers, independent of baseline weight. Our findings suggest that variation in metabolic markers of diabetes across patterns of weight gain is masked by a homogeneous classification of weight gain.