Perceptions of weight and associated factors of adolescents in Jiangsu Province, China

Transition Patterns of Weight Status and Their Predictive Lipid Markers Among Chinese Adults: A Longitudinal Cohort Study Using the Multistate Markov Model

BACKGROUND

Obesity is well recognized as a risk factor for cardiometabolic diseases. The development of obesity is a dynamic process that can be described as a multistate process with an emphasis on transitions between weight states. However, it is still unclear what convenient biomarkers predict transitions between weight states. The aim of this study was to show the dynamic nature of weight status in adults stratified by age and sex and to explore blood markers of metabolic syndrome (MetS) that predict transitions between weight states.

METHODS

This study involved 9795 individuals aged 18 to 56 at study entry who underwent at least two health check-ups in the eight-year period of study in the health check-up centre of our institution. Weight, height and biochemical indices were measured at each check-up. The participants were divided into four groups based on age and sex (young male, middle-aged male, young female and middle-aged female groups). A multistate Markov model containing 3 states (healthy weight, overweight and obesity) was adopted to study the longitudinal weight data.

RESULTS

Young people were more likely to transit between weight states than middle-aged people, and middle-aged people were more resistant to recover from worse states. The mean sojourn time in obesity was greatest in the middle-aged male group (6.23 years), and the predicted rate of obesity beginning with healthy weight was greatest in the young male group (13.7%). In multivariate models, age group and triglyceride (TG) and high-density lipoprotein cholesterol (HDL) levels were significant for specific transitions in females, whereas age group and HDL levels were significant in males. In females, if HDL levels increased 1 mmol/L, the probability of progression from healthy weight to overweight decreased by 37.0% (HR= 0.63), and the probabilities of recovery (overweight to healthy weight and obesity to overweight) increased by 62.0% (HR= 1.62) and 1.23-fold (HR= 2.23), respectively. In males, if TG levels increased 1 mmol/L, the risk of progression from healthy weight to overweight increased by 24.0% (HR= 1.24). Each unit increase in HDL levels was associated with a 0.99-fold (HR= 1.99) increase in the chance of recovery from overweight to healthy weight and with a 0.37-fold (HR= 0.63) decrease in the risk of progression from healthy weight to overweight.

CONCLUSION

The weight status of young people was less stable than that of middle-aged people. Males were more likely to become overweight and more resistant to recover from worse states than females. Young males with healthy weight were more likely to develop obesity than other healthy weight groups. Blood lipid levels, especially HDL, were predictors of weight transitions in adults. Prevention and intervention measures should be applied early.

Trends in Overweight and Obesity Among Children and Adolescents in China from 1991 to 2015: A Meta-Analysis

This meta-analysis of overweight and obesity (ow/ob) among children and adolescents in China from 1991 to 2015 provides a reference for promoting the healthy development of children and adolescents. The studies were retrieved from the China National Knowledge Infrastructure, Wanfang, and PubMed databases for the period from January 1991 to January 2018. The data were combined and analyzed, and the combined effect magnitude odds ratio and the 95% confidence interval were calculated. Publication bias was determined using Stata/SE12.0. We found that (1) the prevalence of ow/ob increased from 5.0% and 1.7% in 1991-1995 to 11.7% and 6.8% in 2011-2015, respectively, and the overweight rate was the greatest in 2006-2010; (2) from 1991 to 2015, the prevalence of ow/ob was greater in urban areas than in rural areas; (3) compared with girls, boys were more likely to be ow/ob; and (4) the prevalence rates of ow and ob were greater in infancy than in other growth stages, with values of 11.7% and 7.0%, respectively. The prevalence of ow/ob among Chinese children and adolescents showed significant differences based on region, sex, and age. An overall upward trend was observed that decreased slightly from 2011 to 2015.

Body Weight Misperception and Weight Disorders among Chinese Children and Adolescents: A Latent Class Analysis

Body misperception plays an important role in the development of weight and dietary disorders among children and adolescents. A school-based health promotion program (2014-2015) was conducted to promote the school health education and improve the teenagers' physical health among Chinese children and adolescents. Based on this program, we intended to examine weight status and weight misperception among Chinese children and adolescents and to explore the relationship between weight misperception and lifestyle behaviors. A total of 10 708 Chinese children and adolescents in 3rd and 7th grade from Shandong and Qinghai province participated in the program. The participants' dietary and activity patterns were clustered by latent class analysis (LCA). Logistic regression analysis was undertaken to explore the relationship between weight perception and demographic factors or dietary and activity patterns. Given the gender-specific difference of children and adolescents, analyses were separately conducted among boys and girls. The total prevalence of weight misperception was 44.50%. Boys, especially those in higher grade and living in wealthier district, were more likely to misperceive body weight. Girls were more likely to overestimate their weight (26.10%) while boys tended to underestimate the weight (28.32%). Three latent dietary and activity patterns including obesogenic pattern, malnourished pattern and healthy pattern were derived. The participants who had weight misperception were more likely to choose unhealthy dietary and exercise activities. The high prevalence of weight misperception was closely related to the unhealthy weight pattern and unhealthy dietary or exercise patterns. Our research found that most children and adolescents failed to perceive their weight correctly and boys tended to underestimate their weight while girls were subjected to overestimation. So, comprehensive intervention programs should focus on improving self-weight awareness, and appropriate guidance should be made to lead the adolescents to more healthy weight pattern.

Parental Perceptions of Obesity in School Children and Subsequent Action

Background: Despite perceiving their child as being above a healthy weight, many parents do not intervene. Little is known about the factors influencing parental action. We assessed parental perception of child's weight status, the prevalence of mitigating parental action, and the underlying factors. Methods: We studied 20,242 children and adolescents from 6 centers across China. Anthropometry was measured by research nurses. Parents answered questionnaires, including their perception of their child's weight status, and any subsequent weight treatment. Results: A total of 3254 children had obesity (16.1%), with 63.0% correctly perceived as overweight by their parents. These children were more likely to be older (≥8 years; p < 0.0001), have severe obesity [adjusted relative risk (aRR) 1.41; p < 0.0001], and have mothers with overweight/obesity (aRR 1.15; p < 0.0001). In particular, parents of children aged <8 years were over five times more likely to perceive their child with overweight/obesity as "thin" than parents of teenagers. Conversely, girls, older children/adolescents, and urban youth were more likely to be wrongly perceived by parents as having an overweight issue. Only one in four children (27.8%) with available information received treatment for their perceived weight problem. Children with severe obesity were more likely to be treated (aRR 1.34; p < 0.0001), as were children of mothers with overweight/obesity (aRR 1.18; p = 0.002). Conclusions: Only one in four Chinese children perceived as overweight by their parents received treatment for their weight problem. Given that overweight/obesity in childhood tracks into adulthood and many parents did not intervene despite perceiving an overweight problem in their child, interventions for childhood obesity need to extend beyond parental perception of children's weight status.

Transition Patterns of Weight Status and Their Associated Factors among Elementary School Children: A Longitudinal Cohort Study Using Multistate Markov Model

Background: Childhood obesity is a recognized public health concern worldwide. It is essential to study the natural progression of obesity in the interest of prevention. This study aimed to describe the dynamic changes in weight status among elementary school children and identify the significant factors influencing the progression or regression of weight status. Methods: This study involved 928 elementary school children who were followed up annually during their elementary school years. Heights, weights, and vital capacity (VC) were measured each school year. A multistate Markov model containing three weight states was fit to longitudinal weight status data. Results: Children with healthy weight and obesity tended to stay in their preceding weight state. Children with overweight, in contrast, were more likely to move to the other two states. The mean sojourn time in obesity and in overweight states was 5.15 years (95% confidence interval [CI]: 4.22-6.3) and 2 years (95% CI: 1.76-2.28), respectively. Children in lower grades, those with a lower VC index, those with a higher initial BMI, those with a higher annual weight increment, and boys were at increased risk of progression to overweight or obesity, with a decreased probability of regression. Conclusions: Children with obesity were more resistant to recovery than those with overweight. Prevention and intervention measures should be adopted early when abnormal weight onset occurs. The multistate Markov model was an advanced tool to analyze dynamic changes in status and identify significant factors for progression and regression and helped to develop prevention and intervention targeting strategies.

Biases in self-reported height and weight measurements and their effects on modeling health outcomes

Self-reported anthropometrics are often used as proxies for measured anthropometrics, but research has shown that heights and weights are often misreported. Using the Study on global AGEing and adult health, I analyze misreporting patterns of height, weight, and BMI in China, India, Russia, and South Africa. Adjustments of self-reported heights and weights using demographic, social, and anthropometric characteristics are evaluated and found to be useful in studying the distribution of anthropometrics within a population. Measured, self-reported, and adjusted BMI are then compared in logistic regression models on the reporting of health outcomes, as well as the resulting accuracy of individual prediction. When BMI is used as a continuous variable in models of health outcomes, measured, self-reported, and adjusted BMI produce similar coefficient estimates, and so self-reported data would be a natural choice because of its accessibility and convenience. In other applications, such as models using categorical BMI and individual prediction using either continuous or categorical BMI, self-reported data in lieu of measured data might not be accurate enough, but adjustments could serve as a potential compromise.

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There is heterogeneity in height and weight reporting patterns.

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Adjustments can be useful in studying population-level distributions.

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Variants of continuous BMI produce similar results in models of health outcomes.

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Variants of categorical BMI should not be used in lieu of measured data.

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Measured BMI is better for individual prediction of health outcomes.

The association between BMI and body weight perception among children and adolescents in Jilin City, China

Objectives

We evaluated the association between BMI and body weight perception in a sample of children and adolescents.

Methods

A cross-sectional school-based study was conducted among 7–18 year-olds (N = 9727) from 4 districts in Jilin City, China. We calculated BMI from measured weight and height and assessed body weight perception using a single questionnaire item. We analyzed these data using SPSS version 20.0.

Results

Approximately 19.8% of these youth perceived themselves as underweight, 57.8% as normal weight, and 22.4% as overweight. In reality, 4.9% were underweight, 64.3% were normal weight, and 30.8% were overweight. Furthermore, approximately 66.4% of these Chinese youth correctly perceived their body image, 28.2% underestimated their true body image, and 5.4% overestimated their weight status. Girls were more likely than boys to overestimate their weight (χ² = 135.4, p < 0.05). Adolescents 13–18 years old were more likely than children 7–12 years old to overestimate their weight (χ² = 248.4, p < 0.05). Senior high school students were the most likely to overestimate their weight (χ² = 297.6, p < 0.05). Kappa tests revealed significant differences in consistency analysis of BMI and body weight perception (Kappa = 0.352, p < 0.05). Kappa < 0.4, the consistency of BMI and body weight perception was poor.

Conclusions

A mismatch existed between BMI and body weight perception among these children and adolescents. Thus, schools and parents should take steps to help them improve weight management and overall health awareness.

The Relationship Between Body Image Concerns and Weight-Related Behaviours of Adolescents and Emerging Adults: A Systematic Review

This systematic review investigates evidence on the association between body image concerns and weight-related behaviours of adolescents and emerging adults. It includes peer-reviewed journal articles reporting research involving body image concerns and weight-related behaviours of adolescents and emerging adults, published between 2005–2017, and located through systematic searches from four databases. This review includes studies from 11 countries or regions: United States (n = 13), Asia (n = 9), Europe (n = 8), Middle East (n = 3), South America (Brazil; n = 3), Canada (n = 3), Australia (n = 1), New Zealand (n = 1), Trinidad (n = 1), Turkey (n = 1) and Seychelles (n = 1); 24 different countries (n = 1); three Asian countries and the United States (n = 1). Out of 46 studies included in this review, 45 studies reported a positive association between body image concerns and weight-related behaviours. Adolescents and emerging adults who misperceived their weight engaged in weight-related behaviours. Higher body dissatisfaction had a significant association in the development of eating disorders and extreme weight-loss behaviours. Body image concerns play a significant role in adolescents and emerging adults engaging in weight-related behaviours. Experimental research designs are required to determine the causality of this association. Evidence strongly suggests policy makers and public health practitioners contemplate strategies to promote positive body image and healthy weight-related behaviours among adolescents and emerging adults.

Self-perception of weight status and its association with weight-related knowledge, attitudes, and behaviors among Chinese children in Guangzhou

Background

How weight perception influences weight-related knowledge, attitudes, and behaviors in Chinese children is unknown. We investigated self-perception of body weight and its correlates, and analyzed the relationship between weight perception and weight-related knowledge, attitudes, and behaviors in children in Guangzhou, China.

Methods

We assessed self-reported weight perception, weight-related knowledge, attitudes, and behaviors in 3752 children aged 7–12 years. Underweight or overweight was defined using the Chinese criteria based on body mass index (BMI). Binary logistic regression analyses were performed to assess correlates of weight underestimation.

Results

In total, 27.3% of children underestimated and 6.7% overestimated their weight status. Weight underestimation was common among normal-weight (34.1%) and overweight children (25.3%). Older age, female sex, and child BMI z-score were negatively associated with normal-weight children's underestimation, whereas older age, paternal obesity, maternal obesity, and child BMI z-score were negatively associated with overweight children's underestimation. Correct answers on weight-related knowledge questions ranged from 81.5% to 98.6% and did not differ by weight perception within BMI categories. Although negative perceivers (i.e., those who perceived themselves as underweight or overweight) had a higher intention to change weight, they behaved more unhealthily on fruit intake, breakfast, screen time, and daily moderate-to-vigorous physical activities time than counterparts.

Conclusion

Weight underestimation was prevalent in normal-weight and overweight children in Guangzhou. Negative perceivers had stronger willingness to change weight but tended to behave more unhealthily on certain behaviors than positive perceivers. Childhood obesity interventions should incorporate health education and practical support to promote healthy eating and physical activity.

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Over one third of children misperceived their weight status in Guangzhou, China.

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Underestimation of body weight was much more prevalent than overestimation.

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Underestimation was common in younger children, girls, and those with obese parents.

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Children perceived as underweight/overweight had a higher intention to change weight.

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Children perceived as normal weight behaved more healthily on certain behaviors.

Elevated transaminase levels among overweight adolescents in eastern China

AIM

We aim to investigate the prevalence and correlates of suspected nonalcoholic fatty liver disease (NAFLD) among adolescents in eastern China.

METHODS

The study uses data from the annual health examination among all students finishing high school who applied for university entrance in Changzhou City between 2012 and 2014 (n = 19 162). Suspected NAFLD was defined as overweight plus elevated alanine aminotransferase levels (males >25.8 U/L; females >22.1 U/L).

RESULTS

The prevalence of suspected NAFLD was 6.9% (11.1% in males and 2.6% in females). Students from medium and high socio-economic status (SES) schools had a higher prevalence of suspected NAFLD than those from low SES schools. Prehypertension had similar odds ratios (ORs, above four) for suspected NAFLD in both genders. The positive association between impaired fasting glucose/diabetes and suspected NAFLD was stronger in females than males. Compared with those born in autumn, these born in spring (OR 1.39; 95% CI, 1.16-1.67) and winter (OR 1.24; 95% CI, 1.04-1.49) had increased odds to have suspected NAFLD in males but not in females.

CONCLUSION

Suspected NAFLD was prevalent among urban university applicants especially in males and those of high SES. Prehypertension was positively related to suspected NAFLD. Season of birth was related to suspected NAFLD in males but not in females.

Obese children are thin in parents' eyes: A psychologically, socially, or culturally driven bias?

Although obesity presents a serious health problem in children, parents often underestimate their children's overweight and obesity status. Therefore, scientific literature was systematically screened through PubMed and PsycINFO to demonstrate the psychological, social, and cultural processes that underlie this evaluation bias. A total of 37 papers that focused on research conducted in different geopolitical contexts were taken into account. Furthermore, a lexicometric analysis of the papers' conclusions was performed. The findings showed that education plays a key role in promoting parents' awareness and their realistic recognition of their children's weight. Accordingly, adequate educational support for parents should be implemented in all healthcare policies addressing childhood obesity.

Weight misperception among young adults with overweight/obesity associated with disordered eating behaviors

OBJECTIVE

The purpose of this study was to examine the cross-sectional association between weight misperception among young adults with overweight/obesity and disordered eating behaviors.

METHOD

In a subsample of young adults with overweight or obesity participating in Wave III (2001-2002) of The National Longitudinal Study of Adolescent to Adult Health (n = 5,184), we examined the cross-sectional association between weight under-perception (i.e., perceiving oneself to be at a healthy body weight or underweight) and disordered eating (fasting/meal skipping for weight control, purging/pills for weight control, overeating/loss of control eating, and use of performance-enhancing products/substances).

RESULTS

About 20% of young adult females under-perceived their weight compared to 48% of males. Individuals who misperceived their weight as healthy were significantly less likely to report fasting/meal skipping (Females: OR: 0.25, 95% CI: 0.14-0.43; Males: OR: 0.31, 95% CI: 0.20-0.48) and vomiting or taking diet pills/laxatives/diuretics (Females: OR: 0.10, 95% CI: 0.04-0.25; Males: OR: 0.10, 95% CI: 0.04-0.25) for weight control. Among females, those who misperceived their weight status as healthy were also less likely to report overeating or loss of control eating (OR: 0.41, 95% CI: 0.24-0.71). Greater use of performance-enhancing products/substances was seen among males who under-perceived their weight as healthy (OR: 2.06, 95% CI: 1.57-2.72) and among both females (OR: 2.29, 95% CI: 1.40-20.0) and males (OR: 2.27, 95% CI: 1.13-4.55) who perceived themselves to be underweight.

DISCUSSION

Weight under-perception among young adults with overweight/obesity may convey some benefit related to disordered eating behaviors, but could be a risk factor for the use of performance-enhancing products/substances. © 2016 Wiley Periodicals, Inc. (Int J Eat Disord ; 49:937-946).

The relationship between distorted body image and lifestyle among Japanese adolescents: a population-based study

Background

Distorted body image plays a significant role in the development of obesity, eating problems, and eating disorders. The aim of this study was to investigate the relationship between distorted body image and lifestyle among Japanese adolescent boys and girls.

Methods

Subjects were 1731 seventh graders (age 12–13 years) from the Ina-town’s junior high schools, Japan, from 2005–2009. The height and weight of each subject were measured. Childhood underweight, overweight, and obesity were defined using the body mass index cutoff points proposed by the International Obesity Task Force. Information regarding the self-perceived weight status and lifestyles (exercise, snacking after dinner, breakfast, wakeup time, bedtime) of each subject was collected using a self-administered questionnaire. Self-perceived weight status was categorized into three groups (thin, normal, or heavy), and compared with the subjects’ actual weight status. Body image perception was categorized into the following three groups: an underestimated own weight status group (underestimated group), a correct own weight status group (correct group) and an overestimated own weight status group (overestimated group).

Results

The proportion of boys in the underestimated group was higher than that of girls, while the opposite was true for the overestimated group (P < 0.001). There were no statistically significant differences in lifestyle between the underestimated group and the correct group regardless of sex. In contrast, there were statistically significant differences between the overestimated group and the correct group in the lifestyle factors of exercise among boys and snacking after dinner among girls. The adjusted odds ratio (OR) in boys who exercised daily significantly decreased (OR: 0.35, 95 % CI: 0.16–0.77), while a significantly increased OR was observed in girls who snacked after dinner (OR: 1.53, 95 % CI: 1.07–2.19).

Conclusion

Adolescent boys tended to underestimate their body weight, whereas adolescent girls were likely to overestimate their body weight. Furthermore, lifestyle factors associated with distorted body image differed by sex, with exercise affecting body image perception among boys and snacking after dinner affecting body image perception among girls. Thus, lifestyle may lead to distorted body image among adolescents.

Diet-related determinants of childhood obesity in urban settings: a comparison between Shanghai and New York

Over the past three decades, both Shanghai and New York City (NYC), have experienced dramatic rises in childhood obesity rates. Given the role that obesity plays in the aetiology of chronic diseases such as diabetes and heart disease, the elevated rates are a major concern. Despite differences in governance systems and cultures, Shanghai and NYC have experienced rapid industrialization, a growing population and a rise in income inequality. The prevalence of childhood obesity in Shanghai and NYC is greater than their respective national rate. However, the trajectory and development of this epidemic has differed between the cities. The distribution of obesity by race and ethnicity, socio-economic status, sex, and age differs markedly between the two cities. To reduce prevalence and inequities within this complex epidemic requires an understanding of the dynamic changes in living conditions among social groups in each city and the behaviours that are influenced by such changes. By comparing changes in the influences on dietary behaviours, such as food distribution, pricing, gender values, and media and marketing, this highlights opportunities for Shanghai, NYC, and other world cities with high or rising rates of childhood obesity to inform future program and policy initiatives. It reiterates the importance of a comprehensive and multilevel approach that includes action at the individual, family, community, municipal, national, and global levels.

Weight misperception and its association with dieting methods and eating behaviors in South Korean adolescents

BACKGROUND/OBJECTIVES

There is little information on the association between weight misperception and eating behavior in Korean adolescents. Therefore, we investigated the association of food intake habits and dieting method and disturbed eating behavior (DEB) in relation to weight misperception.

SUBJECTS/METHODS

Data was collected by using a nationwide online panel survey from 6,943 adolescents enrolled in middle/high school. DEB was measured with the Eating Attitudes Test (EAT-26) and those who scored ≥ 20 on the EAT-26 were considered to have eating disorder. Logistic regressions were conducted to examine the association between weight misperception based on self-reported weight status and dieting method and eating behaviors.

RESULTS

The proportion of weight underestimation was 23.5% and that of overestimation was 24.0%. Weight overestimating girls were more likely to engage in various unhealthy dieting practices (OR = 1.69 for fasting; OR = 1.88 for laxative or diuretic use; OR = 2.05 for self-induced vomiting after meals; P < 0.05). Moreover, there was a strong association between overestimation and undesirable eating behaviors, especially among girls, e.g.: having breakfast (OR = 0.85), high consumption of fast foods (OR = 1.28) and regular sodas (OR = 1.39), but not among boys. In both genders, weight overestimation appears to be a major risk factor for DEB (OR = 1.34 for boys and OR = 1.41 for girls; P < 0.05).

CONSLUSIONS

Weight overestimation is associated with unhealthy weight control practices and eating behaviors. We particularly found a significant association between weight overestimation and DEB among nationwide Korean adolescents.

Weight status in Chinese children: maternal perceptions and child self-assessments

BACKGROUND

Inaccurate parental perceptions of child weight status as well as children's own misperceptions can reduce motivation to adopt optimal nutritional and physical activity behaviors, thereby increasing overweight and obesity risk in child populations in the U.S. and elsewhere. Using population-based data from nine provinces of China, we analyzed the accuracy of maternal perceptions and children's self-assessments of weight status.

METHODS

The data were collected from 1265 children aged 6 to 18 years with self-reported weight status perceptions during the 2006 China Health and Nutrition Survey. Among these children, 863 had maternal estimation of child weight status. Descriptive and multiple regression analyses are conducted to find variations in the misperception of children's weight status.

RESULTS

Among overweight children (n=176), 69% underestimated their weight status; 72% mothers of the overweight children (n=143) also underestimated their child's weight status. Less than one-quarter of overweight children and their mothers chose the correct classification of weight status. Multiple regression analyses showed that as children's body-mass-index (BMI)-for-age increased, the odds that mothers underestimated their weight status increased. Low maternal weight was significantly associated with maternal underestimation of child weight status but not with child's underassessment.

CONCLUSIONS

Underestimation of childhood overweight is common among both mothers and children in China, particularly for children with the highest BMI. School-based BMI reporting may be beneficial in alerting parents and children to the problem and encouraging communication with health care providers.

Chinese parents' perceptions of their children's weights and their relationship to parenting behaviours

PURPOSE

The purpose of this study is to examine Chinese parents' perceptions of their children's weights and explore the parenting behaviours associated with these perceptions.

METHODS

A total of 2143 adolescents and 1869 parents were recruited from secondary schools in Ganzhou and Shantou in China. The adolescents' actual weights and heights were measured by trained testers. The self-reported parents' weights and heights, parental perception of the adolescents' weights, adolescents' perception of their own weights, parenting behaviours and demographic information were collected through the questionnaires distributed to the respondents.

RESULTS

The results based on Kappa statistics show only a slight agreement between parental perception of their children's weights and the adolescents' actual weights (Kappa = 0.221). The results from the logistic regression show that the parents' gender [odds ratio (OR) = 0.80, 95% confidence interval (CI): 0.64-1.00], adolescents' gender (OR = 1.61, 95% CI: 1.29-2.01) and perception of their own weights (OR = 0.30, 95% CI: 0.24-0.38) are associated with the parents' perception of their children's weights. Statistically significant difference in several parenting behaviours was found between the parents with correct and incorrect perceptions of their children's weight.

DISCUSSION AND CONCLUSION

Misconceptions about their children's weights are prevalent among Chinese parents. The association between parents' perception of their children's weight and parenting behaviours suggests that the accurate classification of children's weights could help prevent childhood obesity.

Comparison of overweight, weight perception, and weight-related practices among high school students in three large Chinese cities and two large U.S. cities

PURPOSE

The study compared differences in overweight prevalence, weight perception, and weight-related practices among high school students in five large Chinese and U.S. cities, and informed interventions for childhood obesity in China and the U.S.

METHODS

The data used was collected in 2003 from a representative sample of high school students in Hong Kong, Macau, Taipei, New York and Los Angeles.

RESULTS

The prevalence of overweight high school students in New York City and Los Angeles was about twice as high as in Hong Kong, Macau, and Taipei; however, the proportion of Chinese students perceiving themselves to be overweight was 15% higher than their U.S. counterparts. Independent of actual weight status, perceived overweight was significantly associated with weight control practices (p < .05). U.S. students showed higher levels of moderate and vigorous physical activity, but more hours of watching television than their Chinese counterparts.

CONCLUSION

The continuing pandemic of overweight among youth fosters weight dissatisfaction, which may increase unhealthy weight control practices. Interventions should be designed to prevent overweight without precipitating unhealthy weight control practices by emphasizing an increase in physical activity and a reduction in time watching television.

Weight perception, substance use, and disordered eating behaviors: comparing normal weight and overweight high-school students

Disordered eating behaviors and substance use are two risk factors for the development of serious psychopathology and health concerns in adulthood. Despite the negative outcomes associated with these risky behaviors, few studies have examined potential associations between these risk factors as they occur during adolescence. The importance of accurate or inaccurate weight perception among adolescents has received increased interest given documented associations with nutritional beliefs and weight management strategies. This study examined the associations among the perceptions of weight and substance use with disordered eating behaviors among a diverse sample of normal weight and overweight adolescent males and females. Data came from the 2007 National Youth Risk Behavior Survey (YRBS). The sample consisted of 11,103 adolescents (53.4% female; 44% Caucasian, 21% African American; 13% Hispanic; age responses ranged from 12 and under to 18 and over), with 31.5% meeting criteria for being either at-risk for obesity or already obese (i.e., overweight). As hypothesized, overestimation of weight among normal weight adolescents and accurate perceptions of weight among overweight adolescents were associated with higher rates of disordered eating behaviors. In normal weight adolescents, use of all three substances (tobacco, binge drinking, and cocaine) was associated with each disordered eating behavior. In contrast, findings revealed differences for overweight adolescents between the type of substance use and disordered eating behavior. Post hoc analyses revealed that gender moderated some of these relationships among overweight individuals. Implications for the development and implementation of secondary prevention programs aimed at reducing disordered eating behaviors, substance use, and obesity risk among normal and overweight adolescents are considered.

Factors associated with weight loss dieting among adolescents: the 11-year follow-up of the 1993 Pelotas (Brazil) birth cohort study

Evidence has shown the negative effects of unsupervised diets and those with excessive calorie restriction. The aim of this study was to determine the proportion of adolescents engaging in weight loss dieting and associated factors. This was a cross-sectional study of 4,452 adolescents born in Pelotas, Rio Grande do Sul State, Brazil, in 1993. The outcome was defined as adolescents that reported having practiced some type of weight loss dieting in the previous 12 months. Prevalence of such dieting was 8.6% (95%CI: 7.7;9.4), and was higher in girls. Elevated maternal body mass index (BMI) was associated with dieting among girls. The adolescent's and parents' view of the adolescent's weight, excess weight, and consumption of diet or light soft drinks were associated with adolescent dieting. There was a positive association between dieting and socioeconomic status. The findings provide important backing for policies aimed at improving adolescents' diet, since they express a major concern over weight and thus a significant percentage of individuals with erroneous and unhealthy behaviors.

Where perception meets reality: self-perception of weight in overweight adolescents

OBJECTIVE

The goal of this study was to examine weight misperception among overweight adolescents in recent years and compare the demographic characteristics and weight-related behaviors of overweight adolescents who accurately and inaccurately perceive their weight status.

METHODS

We used data from the nationally representative Youth Risk Behavior Surveillance System, collected every 2 years from 1999 through 2007. On the basis of self-reported height and weight, BMI percentile for age and sex was calculated. Overweight and obese respondents (BMI > or = 85th percentile) were classified into 2 groups: (1) misperceivers (weight perception "about right" or "underweight") or (2) accurate perceivers (weight perception "overweight"). We examined the proportion of misperceivers at each time point. Using the 2007 data, we compared demographic characteristics and weight-related behaviors of accurate perceivers and misperceivers with bivariate and multivariate analyses.

RESULTS

Among overweight adolescents, the overall proportion of misperceivers ranged between 29% and 33% from 1999 through 2007. In 2007, 23% of overweight girls and 40% of overweight boys were misperceivers (P < .001). Both male and female accurate perceivers were significantly more likely than misperceivers to report trying to maintain or lose weight, exercising for weight control, and eating less for weight control. Adjusting for age, race/ethnicity, and BMI percentile, no significant differences in unhealthy weight-related behaviors were found between accurate perceivers and misperceivers in boys or girls. Male accurate perceivers were significantly less likely to report achieving recommended levels of fruit and vegetable intake and physical activity.

CONCLUSIONS

Nearly 3 in 10 overweight adolescents do not consider themselves overweight. Those with an accurate weight perception reported some healthy weight-related behaviors but not higher levels of unhealthy weight-related behaviors. With the substantial prevalence of weight misperception, clinicians should consider their patients' perceived weight status when pursuing patient-centered counseling of overweight adolescents.

Health-related physical fitness and weight status in Hong Kong adolescents

Background

This study was designed to investigate the relation between health-related physical fitness and weight status in Hong Kong adolescents.

Methods

3,204 students aged 12-18 years participated in the Hong Kong Student Obesity Surveillance (HKSOS) project in 2006-2007. Anthropometric measures (height, weight) and health-related fitness (push-up, sit-up, sit-and-reach, 9-minute run) were assessed. Body mass index (BMI) was computed to classify participants into normal weight, underweight (Grade I, II/III), overweight, and obese groups. The associations of health-related physical fitness with BMI and weight status were examined by partial correlation coefficients and analysis of covariance, respectively.

Results

More boys than girls were overweight or obese (18.0% vs 8.7%), but more girls than boys were underweight (22.3% vs 16.7%). Boys performed significantly (P < 0.001) better in sit-up (38.8 vs 31.6 times/min) and 9-minute run (1632.1 vs 1353.2 m), but poorer in sit-and-reach (27.4 vs 32.2 cm) than girls. All four physical fitness tests were significantly positively correlated with each other in both sexes, and BMI was only weakly correlated with sit up and sit-and-reach tests in boys. Decreasing performance (P for trend < 0.05) was observed from normal weight to overweight and obese for push-up, sit-up, and 9-minute run in both sexes. From normal weight to Grade I and Grade II/III underweight, decreasing performance (P for trend < 0.05) for sit-up and sit-and-reach in both sexes and for push-up in boys was observed.

Conclusions

The relations between BMI and health-related physical fitness in adolescents were non-linear. Overweight/obese and underweight adolescents had poorer performance in push-up and sit-up tests than normal weight adolescents. Different aspects of health-related physical fitness may serve as immediate indicators of potential health risks for underweight and overweight adolescents.

Adolescents' experience of comments about their weight - prevalence, accuracy and effects on weight misperception

Background

Weight comments are commonly received by adolescents, but the accuracy of the comments and their effects on weight misperception are unclear. We assessed the prevalence and accuracy of weight comments received by Chinese adolescents from different sources and their relation to weight misperception.

Methods

In the Hong Kong Student Obesity Surveillance (HKSOS) project 2006–07, 22612 students aged 11–18 (41.5% boys) completed a questionnaire on obesity. Students responded if family members, peers and professionals had seriously commented over the past 30 days that they were "too fat" or "too thin" in two separate questions. The accuracy of the comments was judged against the actual weight status derived from self-reported height and weight. Self-perceived weight status was also reported and any discordance with the actual weight status denoted weight misperception. Logistic regression yielded adjusted odd ratios for weight misperception by the type of weight comments received.

Results

One in three students received weight comments, and the mother was the most common source of weight comments. Health professional was the most accurate source of weight comments, yet less than half the comments were correct. Adolescents receiving incorrect comments had increased risk of having weight misperception in all weight status groups. Receiving conflicting comments was positively associated with weight misperception among normal weight adolescents. In contrast, underweight and overweight/obese adolescents receiving correct weight comments were less likely to have weight misperception.

Conclusion

Weight comments, mostly incorrect, were commonly received by Chinese adolescents in Hong Kong, and such incorrect comments were associated with weight misperception.

Predicting changes in eating disorder symptoms among adolescents in China: an 18-month prospective study

This 18-month prospective study investigated factors that contributed to changes in eating disorder symptoms among adolescents living in the People's Republic of China. Five hundred forty-one Chinese middle school and high school students (182 boys, 359 girls) completed measures of eating disorder symptoms; body dissatisfaction; appearance ideal endorsements; negative affect; and appearance-based social pressure, teasing, and comparison. For girls, baseline levels of negative affect, preference for a thin appearance ideal, and fatness concern made unique contributions to reported eating disturbances at the 18-month follow-up. For boys, baseline body mass index and fatness concerns were the only significant univariate predictors of changes in eating pathology.

Benefits of Breakfast for Children and Adolescents: Update and Recommendations for Practitioners

A number of studies report health benefits for children and adolescents who consume breakfast. Breakfast skipping is fairly common in children and adolescents and increases as children age. Breakfast can enhance children's diets by positively contributing to daily nutrient intake, augmenting intake of key nutrients such as fiber and calcium, and provides an opportunity to help meet the recommendations of the Dietary Guidelines for Americans. Breakfast also is associated with more healthful food choices. Cross-sectional studies support that eating breakfast more often may help children and adolescents maintain a healthful weight. However, the results from longitudinal studies are inconclusive and suggest that more research is needed to clarify this relationship, including understanding the mediating effects of initial weight status, dieting behavior, and physical activity levels. Breakfast consumption may provide some benefit toward cognitive function and academic achievement, but more research is needed. Breakfast is one facet of a healthy lifestyle that may help contribute to the short- and long-term health and well-being of children and adolescents. Health practitioners can promote healthy breakfast consumption in children and adolescents by addressing barriers to eating breakfast and focusing on individuals who may be more likely to skip breakfast on a regular basis.

Vegetable-rich food pattern is related to obesity in China

OBJECTIVE

To investigate the association between a vegetable-rich food pattern and obesity among Chinese adults.

DESIGN

A food pattern rich in vegetables is associated with lower risk of obesity and non-communicable chronic disease in Western countries. A similar food pattern is found in the Chinese population but the cooking method is different. A cross-sectional household survey of 2849 men and women aged 20 years and over was undertaken in 2002 in Jiangsu Province (response rate, 89.0%). Food intake was assessed by food frequency questionnaire. Factor analysis was used to identify food patterns. Nutrient intake was measured by food weighing plus consecutive individual 3-day food records. Height, weight and waist circumference were measured.

RESULTS

The prevalence of general obesity (BMI > or =28 kg m(-2)) was 8.0% in men and 12.7% in women, central obesity was 19.5% (> or =90 cm) and 38.2% (> or =80 cm), respectively. A four-factor solution explained 28.5% of the total variance in food frequency intake. The vegetable-rich food pattern (whole grains, fruits and vegetables) was positively associated with vegetable oil and energy intake. Prevalence of obesity/central obesity increased across the quartiles of vegetable-rich food pattern. After adjusting for sociodemographic factors and four distinct food patterns, the vegetable-rich pattern was independently associated with obesity. Compared with the lowest quartile of vegetable-rich pattern, the highest quartile had higher risk of general obesity (men, prevalence ratio (PR): 1.82, 95% confidence interval (CI): 1.05-3.14; women, PR: 2.25, 95% CI: 1.45-3.49).

CONCLUSION

The vegetable-rich food pattern was associated with higher risk of obesity/central obesity in Chinese adults in both genders. This association can be linked to the high intake of energy due to generous use of oil for stir-frying the vegetables.

Convergence of obesity and high glycemic diet on compounding diabetes and cardiovascular risks in modernizing China: an emerging public health dilemma

As China is undergoing dramatic development, it is also experiencing major societal changes, including an emerging obesity epidemic, with the prevalence of overweight and obesity doubling in the past decade. However, the implications of a high glycemic index (GI) and glycemic load (GL) traditional Chinese diet are adversely changing in modern times, as a high-glycemic diet is becoming a greater contributor to diabetes and cardiovascular risks in a population with rising obesity and decreasing physical activity. Specifically, a high GI diet adversely impacts metabolism and appetite control regulation, and notably confers substantially greater risk of weight gain, type 2 diabetes, cardiovascular disease, and certain cancers among overweight and obese individuals (P<0.05 for all); leading to an emerging vicious cycle of compounding adverse health risks. Notably, while no elevated risk of cardiovascular disease and type 2 diabetes were observed with higher GL intake among normal weight individuals, among overweight individuals, higher GL was strongly associated with higher risk of coronary heart disease (RR=2.00, 95%CI: 1.31-2.96), stroke (RR=2.13, 1.28-3.53), and type 2 diabetes (RR=1.52, 1.22-1.89 among Chinese). Additionally, the influx of Western-diets rich in saturated fats and high-glycemic sugar-sweetened beverages also threaten the health of the population. This review highlights the emerging adverse convergence of a high-glycemic Asian diet with a Chinese society experiencing an emerging obesity epidemic, and the important implications of these combined factors on compounding cardiometabolic risks. Potential policy directions in China are also discussed.