[Show abstract][Hide abstract] ABSTRACT: 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.
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.
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.
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.
Full-text · Article · Dec 2015 · International Journal of Behavioral Nutrition and Physical Activity
[Show abstract][Hide abstract] ABSTRACT: The processed food sector in low- and middle-income countries has grown rapidly. Little is understood about its effect on obesity. Using data from 14,976 participants aged two and older in the 2011 China Health and Nutrition Survey, this paper examines patterns of processed food consumption and their impacts on obesity while considering the endogeneity of those who purchase processed foods. A major assumption of our analysis of the impact of processed foods on overweight and obesity was that the consumption of processed foods is endogenous due to their accessibility and urbanicity levels. The results show that 74.5% of participants consumed processed foods, excluding edible oils and other condiments; 28.5% of participants' total daily energy intake (EI) was from processed foods. Children and teenagers in megacities had the highest proportion of EI (40.2%) from processed foods. People who lived in megacities or highly urbanized neighborhoods with higher incomes and educational achievement consumed more processed foods. When controlling for endogeneity, only the body mass index (BMI) and risk of being overweight of children ages two to eighteen are adversely associated with processed foods (+4.97 BMI units, 95% confidence interval (CI): 1.66-8.28; odds ratio (OR) = 3.63, 95% CI: 1.45-9.13). Processed food purchases represent less than a third of current Chinese food purchases. However, processed food purchases are growing at the rate of 50% per year, and we must begin to understand the implications for the future.
[Show abstract][Hide abstract] ABSTRACT: To examine the acceptability and feasibility of using smartphone technology to assess beverage intake and evaluate whether the feasibility of smartphone use is greater among key sub-populations.
An acceptability and feasibility study of recording the video dietary record, the acceptability of the ecological momentary assessment (EMA), wearing smartphones and whether the videos helped participants recall intake after a cross-over validation study.
Rural and urban area in Shanghai, China.
Healthy adults (n 110) aged 20-40 years old.
Most participants reported that the phone was acceptable in most aspects, including that videos were easy to use (70 %), helped with recalls (77 %), EMA reminders helped them record intake (75 %) and apps were easy to understand (85 %). However, 49 % of the participants reported that they had trouble remembering to take videos of the beverages before consumption or 46 % felt embarrassed taking videos in front of others. Moreover, 72 % reported that the EMA reminders affected their consumption. When assessing overall acceptability of using smartphones, 72 % of the participants were favourable responders. There were no statistically significant differences in overall acceptability for overweight v. normal-weight participants or for rural v. urban residents. However, we did find that the overall acceptability was higher for males (81 %) than females (61 %, P=0·017).
Our study did not find smartphone technology helped with dietary assessments in a Chinese population. However, simpler approaches, such as using photographs instead of videos, may be more feasible for enhancing 24 h dietary recalls.
Full-text · Article · Apr 2015 · Public Health Nutrition
[Show abstract][Hide abstract] ABSTRACT: Little is known about whether large-scale environmental changes, such as those seen with urbanization, are differentially associated with SBP versus DBP, and whether those changes vary by birth cohort.
We used data from the China Health and Nutrition Survey, a population-based cohort study of Chinese adults (n = 18 754 aged 18-70 years), seen a maximum of seven times from 1991 to 2009. We used hierarchical multivariable linear models to simultaneously estimate SBP and DBP as correlated outcomes over time, accounting for their physiologic, time-varying correlation. Main exposure variables were urbanicity, age, and birth cohort. Over 18 years of modernization, median SBP and DBP increased by 10 and 7 mmHg, respectively.
Our hierarchical model results suggest greater temporal increases in SBP and particularly DBP at lower versus higher urbanicity. At the same chronological age, for a 10-year difference in birth cohort (i.e. born in 1980s versus 1970s), the adjusted mean DBP was approximately 3 mmHg higher for the later birth cohort (P < 0.001). Pulse pressure (calculated as model-predicted SBP minus DBP) was also higher at low versus high urbanicity.
These results suggest increased susceptibility of DBP (and thus peripheral vascular resistance) to environmental change, particularly in younger Chinese adults. Because DBP more strongly predicts cardiovascular disease risk in younger adulthood, hypertension-related health burden in China may increase over time.
No preview · Article · Feb 2015 · Journal of Hypertension
[Show abstract][Hide abstract] ABSTRACT: Aims:
To identify dietary patterns that influence cardiometabolic risk among individuals with type 1 diabetes (T1D) in China.
Data are from a cross-sectional study of T1D in China (n=99). Dietary intake was assessed using three 24-hour recalls. Reduced rank regression was used to identify dietary patterns from a set of 20 food groups that maximized the explained variation in glycated hemoglobin A1c (HbA1c) and low-density lipoprotein (LDL) cholesterol.
Dietary pattern 1 was characterized by low intakes of wheat products and high-fat cakes, and high intakes of beans and pickled vegetables. Dietary pattern 2 was characterized by low intakes of high-fat cakes, nuts/seeds, fish/shellfish, and teas/coffee, and high intakes of rice and eggs. Participants in the highest tertile of dietary pattern 1 had significantly (p<0.05) higher HbA1c and LDL cholesterol compared to participants in the lowest tertile: mean difference in HbA1c was 1.0 percentage point (11 mmol/mol) and in LDL cholesterol was 0.36 mmol/L after adjustment for age and household income. Dietary pattern 2 was not associated with HbA1c or LDL cholesterol.
We identified a dietary pattern that is significantly related to HbA1c and LDL cholesterol. These findings provide support for behavioral strategies to prevent complications in individuals with T1D in China.
No preview · Article · Dec 2014 · Journal of Diabetes and its Complications
[Show abstract][Hide abstract] ABSTRACT: This paper addresses the need for diet assessment methods that capture the rapidly changing beverage consumption patterns in China. The objective of this study was to develop a 3-day smartphone-assisted 24-hour recall to improve the quantification of beverage intake amongst young Chinese adults (n=110) and validate, in a small subset (n=34), the extent to which the written record and smartphone-assisted recalls adequately estimated total fluid intake, using 24-hour urine samples. The smartphone-assisted method showed improved validity compared with the written record-assisted method, when comparing reported total fluid intake to total urine volume. However, participants reported consuming fewer beverages on the smartphone-assisted method compared with the written record-assisted method, primarily due to decreased consumption of traditional zero-energy beverages (i.e. water, tea) in the smartphone-assisted method. It is unclear why participants reported fewer beverages in the smartphone-assisted method than the written record -assisted method. One possibility is that participants found the smartphone method too cumbersome, and responded by decreasing beverage intake. These results suggest that smartphone-assisted 24-hour recalls perform comparably but do not appear to substantially improve beverage quantification compared with the current written record-based approach. In addition, we piloted a beverage screener to identify consumers of episodically consumed SSBs. As expected, a substantially higher proportion of consumers reported consuming SSBs on the beverage screener compared with either recall type, suggesting that a beverage screener may be useful in characterizing consumption of episodically consumed beverages in China's dynamic food and beverage landscape.
No preview · Article · Dec 2014 · Asia Pacific Journal of Clinical Nutrition
[Show abstract][Hide abstract] ABSTRACT: Recent studies have shown inconsistent effects of sodium reduction, potassium intake, and the ratio of sodium to potassium (Na/K ratio) on hypertension and other cardiovascular diseases. Major gaps exist in knowledge regarding these issues in China.
We analyzed the patterns and trends of dietary sodium intake, potassium intake, and the Na/K ratio and their relations with incident hypertension in China.
The China Health and Nutrition Survey cohort includes 16,869 adults aged 20-60 y from 1991 to 2009. Three consecutive 24-h dietary recalls and condiment and food weights provided detailed dietary data. Multinomial logistic regression models determined trends and patterns of sodium and potassium intake and the Na/K ratio. Models for survival-time data estimated the hazard of incident hypertension.
Sodium intake is decreasing but remains double the Institute of Medicine recommendations. Most sodium comes from added condiments. Adults in the central provinces have the highest sodium intake and the most rapid increase in hypertension. Potassium intake has increased slightly but is below half of the recommended amount. The Na/K ratio is significantly higher than the recommended amounts. Recent measurements of high sodium intake, low potassium intake, and high Na/K ratio have strong independent dose-response associations with incident hypertension.
Reducing sodium in processed foods, the major public health strategy in Western countries, may be less effective in China, where salt intake remains high. Replacing sodium with potassium in salt to control and prevent hypertension in China should be considered along with other public health and clinical prevention options.
No preview · Article · Nov 2013 · American Journal of Clinical Nutrition
[Show abstract][Hide abstract] ABSTRACT: Recent US work identified "metabolically healthy overweight" and "metabolically at risk normal weight" individuals. Less is known for modernizing countries with recent increased obesity.
Fasting blood samples, anthropometry and blood pressure from 8,233 adults aged 18-98 in the 2009 nationwide China Health and Nutrition Survey, were used to determine prevalence of overweight (Asian cut point, BMI ≥23 kg/m(2) ) and five risk factors (prediabetes/diabetes (hemoglobin A1c ≥5.7%) inflammation (high-sensitivity C-reactive protein (hsCRP) ≥3 mg/l), prehypertension/hypertension (Systolic blood pressure/diastolic blood pressure≥130/85 mm Hg), high triglycerides (≥150 mg/dl), low high-density lipoprotein cholesterol (<40 (men)/ <50 mg/dl (women)). Sex-stratified, logistic, and multinomial logistic regression models estimated concurrent obesity and cardiometabolic risk, with and without abdominal obesity, adjusting for age, smoking, alcohol consumption, physical activity, urbanicity, and income.
Irrespective of urbanicity, 78.3% of the sample had ≥1 elevated cardiometabolic risk factor (normal weight: 33.2% had ≥1 elevated risk factor; overweight: 5.7% had none). At the age of 18-30 years, 47.4% had no elevated risk factors, which dropped to 6% by the age 70, largely due to age-related increase in hypertension risk (18-30 years: 11%; >70 years: 73%). Abdominal obesity was highly predictive of metabolic risk, irrespective of overweight (e.g., "metabolically at risk overweight" relative to "metabolically healthy normal weight" (men: relative risk ratio (RRR) = 39.06; 95% confidence interval (CI): 23.47, 65.00; women: RRR = 22.26; 95% CI: 17.49, 28.33)).
A large proportion of Chinese adults have metabolic abnormalities. High hypertension risk with age, underlies the low prevalence of metabolically healthy overweight. Screening for cardiometabolic-related outcomes dependent upon overweight will likely miss a large portion of the Chinese at risk population.
[Show abstract][Hide abstract] ABSTRACT: Background:
Although it is clear that there are short-term effects of sodium intake on blood pressure, little is known about the most relevant timing of sodium exposure for the onset of hypertension. This question can be addressed only in cohorts with repeated measures of sodium intake.
Using up to seven measures of dietary sodium intake and blood pressure between 1991 and 2009, we compared the association of baseline, mean, and most recent sodium intake with incident hypertension, in 6578 adults enrolled in the China Health and Nutrition Survey (age 18 to 65 years and free of hypertension at baseline). We used survival methods that account for the interval-censored nature of this study and inverse-probability weights to generate adjusted survival curves and time-specific cumulative risk differences; hazard ratios were also estimated.
Baseline sodium intake was not associated with incident hypertension. For the mean and most recent measures, the probability of hypertension-free survival was the lowest among those with the highest sodium intake compared with all other intake groups across the entire follow-up. In addition, the most recent sodium intake had a positive dose-response association with incident hypertension (risk difference at 11 years of follow-up = 0.04 [95% confidence interval = 0.00 to 0.08], 0.06 [0.02 to 0.11], 0.18 [0.12 to 0.24], and 0.20 [0.12 to 0.27] for the second to fifth sodium-intake groups compared with the lowest group, respectively).
We found that, among the various time frames, the most recent exposure to sodium was most strongly associated with incident hypertension.
No preview · Article · Mar 2013 · Epidemiology (Cambridge, Mass.)
[Show abstract][Hide abstract] ABSTRACT: It has been hypothesized that monosodium glutamate (MSG), a flavor enhancer, is positively associated with weight gain, which influences energy balance through the disruption of the hypothalamic signaling cascade of leptin action.
The objective was to examine the longitudinal association between MSG consumption and incidence of overweight.
Data were collected from the China Health and Nutrition Survey (CHNS), a prospective open-cohort, ongoing nationwide health and nutrition survey, consisting of 10,095 apparently healthy Chinese adults aged 18-65 y at entry from 1991 to 2006. Diet, including MSG and other condiments, was assessed with a weighed food inventory in combination with three 24-h recalls. Incident overweight was defined as a body mass index (BMI; in kg/m(2)) ≥ 25 or ≥23 based on World Health Organization recommendations for Asian populations. Multilevel mixed-effects models were constructed to estimate change in BMI, and Cox regression models with gamma shared frailty were used to determine the incidence of overweight.
The mean follow-up was 5.5 y. The cumulative mean (±SD) MSG intake of 2.2 ± 1.6 g/d was positively associated with BMI after adjustment for potential confounders and cluster effects at different levels (individual, household, and community). The adjusted hazard ratio of overweight was 1.33 (95% CI: 1.01, 1.75; P for trend < 0.01) for participants in the highest quintile of MSG intake compared with those in the lowest quintile after adjustment for age, physical activity, total energy intake, and other major lifestyle factors.
MSG consumption was positively, longitudinally associated with overweight development among apparently healthy Chinese adults. Additional studies are needed to elucidate mechanisms of action and to establish causal inference.
Full-text · Article · Apr 2011 · American Journal of Clinical Nutrition
[Show abstract][Hide abstract] ABSTRACT: Television (TV) use has been linked with poor eating behaviors and obesity in young people. This study examines the association between TV watching and paying attention to TV commercials with buying and requesting snacks seen on commercials, and eating snacks while watching TV among youth in China.
Data from 1,552 participants (ages 6-17.99) in the 2004 China Health and Nutrition Survey were analyzed cross-sectionally. The 2004 China Health and Nutrition Survey was conducted in nine Chinese provinces.
Most respondents (92.2%) reported watching TV; on average children (6-11.99 years old) and adolescents (12-17.99 years old) watched TV for 9-10 hours per week. Nearly half (42.9%) of all the respondents said they "sometimes" or "often" paid attention to TV commercials. Respondents who reported paying attention to commercials had higher odds of requesting snacks (odds ratio [OR] = 3.43; 95% confidence interval [CI] = 2.55-4.60) and buying snacks (OR = 2.73; 95% CI = 2.17-3.43) seen on TV, and eating snacks while watching TV (OR = 1.60; 95% CI = 1.23-2.07) than those who did not pay attention. However, frequency of watching TV was not significantly related to snacking.
Attention to TV commercials for snack foods may be one of the factors affecting the increase in obesity among children and adolescents in China.
Full-text · Article · Apr 2010 · Journal of Adolescent Health
[Show abstract][Hide abstract] ABSTRACT: China's overweight and obesity problems are increasing at an alarming rate, particularly among youth, due apparently to excessive caloric intake, low physical activity, and sedentary lifestyles. Increasing television (TV) viewing may also be a contributing factor.
This study examines the relationship between TV watching, physical activity and snacking behaviors among Chinese children and adolescents between 2000 and 2006. Responses from 4,643 total participants aged 6 through 18 in three waves (2000, 2004, and 2006) of the China Health and Nutrition Survey (CHNS) were analyzed cross-sectionally to evaluate trends of weekly TV watching time, number of and duration of physical activities per week, and snacking behaviors.
Results showed that TV watching among youth increased from six hours per week in 2000 to nearly 11 hours in 2006. The average number of weekly physical activities also increased, but the duration of activity did not increase. Weekly TV watching time was negatively related to the number of physical activities engaged in by youth. This negative relationship is more pronounced over time. The instance of youth requests to their parents for snacks seen on TV also increased slightly between 2004 and 2006.
These cross-sectional trends indicate that TV watching may be one of the factors in the growing problem of obesity among children and adolescents in China, as it is associated with changes in physical activity and snacking across a large number of Chinese youth.
[Show abstract][Hide abstract] ABSTRACT: The aim of the prospective study reported here was to examine the effects of social and economic transformation on dietary patterns and nutritional status in China. The study began in 1989 and continued with follow-ups in 1991, 1993, 1997, 2000, and 2004. A total of 5000 subjects aged 18-45 years from 4280 households in nine provinces were included. Weighed records and three consecutive 24-h recalls were used. Over the study period, average consumption of all animal foods except milk increased, while cereal intake decreased. The proportion of animal protein and fat as a percentage of energy also increased. However, vitamin A and calcium intake did not increase and remained low. Child height and weight increased while undernutrition decreased and overweight increased. The results indicate that rapid changes in dietary pattern are associated with economic reforms in China.
Full-text · Article · May 2009 · Nutrition Reviews