Definitions of childhood obesity: current practice

Childhood Obesity: An Updated Review

BACKGROUND

Childhood obesity is an important and serious public health problem worldwide.

OBJECTIVE

This article aims to familiarize physicians with the evaluation, management, and prevention of childhood.

METHODS

A PubMed search was conducted in May, 2021, in Clinical Queries using the key terms "obesity" OR "obese". The search included clinical trials, randomized controlled trials, case-control studies, cohort studies, meta-analyses, observational studies, clinical guidelines, case reports, case series, and reviews. The search was restricted to English literature and children. The information retrieved from the above search was used in the compilation of the present article.

RESULTS

Most obese children have exogenous obesity characterized by a growth rate for height above the 50th percentile, normal intelligence, normal genitalia, and lack of historical or physical evidence of an endocrine abnormality or a congenital syndrome. Obese children are at risk for dyslipidemia, hypertension, diabetes mellitus, non-alcoholic fatty liver disease, obstructive sleep apnea, psychosocial disturbances, impaired quality of life, and shorter life expectancy. The multitude of serious comorbidities necessitates effective treatment modalities. Dietary modification, therapeutic exercise, and behavioral modification are the fundamentals of treatment. Pharmacotherapy and/or bariatric surgery should be considered for obese individuals who do not respond to the above measures and suffer from a serious comorbid condition.

CONCLUSION

Childhood obesity, once established, is often refractory to treatment. Most treatment programs lead to a brief period of weight loss, followed by rapid re-accumulation of the lost weight after the termination of therapy. As such, preventive activity is the key to solving the problem of childhood obesity. Childhood obesity can be prevented by promoting a healthy diet, regular physical activity, and lifestyle modification. Parents should be encouraged to get involved in school and community programs that improve their children's nutritional status and physical activity.

Association Between Breastfeeding and Obesity in Preschool Children

Introduction

Childhood obesity is a significant problem nowadays, with breastfeeding being one of many factors responsible for this issue. Breastfeeding as a natural way of feeding infants has many benefits for the child, the mother, and society.

Aim

The present study aimed to investigate the association between overweight children in preschool age and breastfeeding duration.

Methods

The current study included 674 preschool children aged 2-5 who attended various municipal kindergartens in South Athens. Questionnaires were given to parents where they recorded the child's personal and body data, parenting, and questions about pregnancy and lactation. The effect of BMI on the duration of breastfeeding in children was examined by the chi-square independence test. Fisher's and Monte Carlo simulations were also used. For data processing, Z scores and percentiles BMI for the first, second until fifth year of the child were found and based on these values the following categorization was performed; for values below -2 as low weight, values from -2 to 1 as normal weight, from 2 to 3 as overweight and over 3 as obese children. The Corresponding categorization was based on the 3rd, 85th, 97th, and 99.9th percentage position.

Results

The percentage of children at preschool age who have been breastfed for over six months and had normal weight was higher than those who breastfed below six months. Moreover, the proportion of children who were low weight, overweight and obese was lower in children who had been breastfed more than six months compared to those who breastfed for a shorter period. Additionally, a statistically significant difference was found for the effect of breastfeeding on childhood obesity in children aged 2 to 5 years.

Conclusion

There is a statistical association between breastfeeding duration and body weight in preschool age. Breastfeeding for more than six months has a positive impact on the child's weight.

Low Diagnostic Accuracy of Body Mass Index-Based and Waist Circumference-Based References of Childhood Overweight and Obesity in Identifying Overfat among Chinese Children and Adolescents

This study aimed to investigate the diagnostic accuracy of body mass index- (BMI-) based and waist circumference- (WC-) based references for childhood overweight and obesity in screening overfat individuals among 2134 Chinese children and adolescents. In this study, overfat status was defined as over 25% body fat for boys and over 30% for girls. Childhood obesity or overweight was defined by four BMI-based references and two WC-based references. All BMI-based references for obesity showed low sensitivity (SE) (0.128–0.473) but high specificity (SP) (0.971–0.998) in detecting overfat individuals in the current population. SE values increased from 0.493 to 0.881 when BMI- and WC-based references for overweight were used to detect overfat individuals. All references for overweight showed high SP rates (0.816–0.966). To improve diagnostic accuracy for childhood obesity, further studies may define a cut-off value for childhood obesity specific for a local population and ethnicity by using health-related overfat data.

Cross-Sectional Growth References and Implications for the Development of an International Growth Standard for School-Aged Children and Adolescents

Normative data are needed to create a reference that indicates optimal development of weight in relation to height and age, particularly in the face of the unfolding obesity epidemic. The body-mass index (BMI) has some serious limitations: it is a relatively poor predictor of current and future fatness. Currently, however, there are few available alternatives, with the possible exception of waist circumference or skinfolds. The use of cross-sectional references to construct a BMI-reference curve is problematic when there are period and cohort effects. Ideally, a reference would be based on longitudinal data in populations with little underweight, overweight, and obesity.

In the meantime cross-sectional data in appropriate populations could be used to construct BMI percentiles linking BMI values at age 5 to those at age 18 (or 21) that would correspond with adult BMI values reflecting optimal health (e.g., that would correspond to adult BMI values between 21 and 23 kg/m2).

From Genome-Wide Association Study to Phenome-Wide Association Study: New Paradigms in Obesity Research

Obesity is a condition in which excess body fat has accumulated over an extent that increases the risk of many chronic diseases. The current clinical classification of obesity is based on measurement of body mass index (BMI), waist-hip ratio, and body fat percentage. However, these measurements do not account for the wide individual variations in fat distribution, degree of fatness or health risks, and genetic variants identified in the genome-wide association studies (GWAS). In this review, we will address this important issue with the introduction of phenome, phenomics, and phenome-wide association study (PheWAS). We will discuss the new paradigm shift from GWAS to PheWAS in obesity research. In the era of precision medicine, phenomics and PheWAS provide the required approaches to better definition and classification of obesity according to the association of obese phenome with their unique molecular makeup, lifestyle, and environmental impact.

Diagnostic accuracy of different body weight and height-based definitions of childhood obesity in identifying overfat among Chinese children and adolescents: a cross-sectional study

Background

Various body weight and height-based references are used to define obese children and adolescents. However, no study investigating the diagnostic accuracies of the definitions of obesity and overweight in Hong Kong Chinese children and adolescents has been conducted. The current study aims to investigate the diagnostic accuracy of BMI-based definitions and 1993 HK reference in screening excess body fat among Hong Kong Chinese children and adolescents.

Methods

A total of 2,134 participants (1,135 boys and 999 girls) were recruited from local schools. The foot-to-foot BIA scale was applied to assess %BF using standard methods. The criterion of childhood obesity (i.e., overfat) was defined as over 25 %BF for boys and over 30 %BF for girls. Childhood obesity was also determined from four BMI-based references and the 1993 HK reference. The diagnostic accuracy of these existing definitions for childhood obesity in screening excess body fat was evaluated using diagnostic indices.

Results

Overall, %BF was significantly correlated with anthropometry measurements in both genders (in boys, r = 0.747 for BMI 0.766 for PWH; in girls, r = 0.930 for BMI 0.851 for PWH). The prevalence rates of overweight and obesity determined by BMI-based references were similar with the prevalence rates of obesity in the 1993 HK reference in both genders. All definitions for childhood obesity showed low sensitivity (in boys, 0.325–0.761; in girls, 0.128–0.588) in detecting overfat. Specificities were high for cut-offs among all definitions for childhood obesity (in boys, 0.862–0.980; in girls, 0.973–0.998).

Conclusions

In conclusion, prevalence rates of childhood obesity or overweight varied widely according to the diagnostic references applied. The diagnostic performance for weight and height-based references for obesity is poorer than expected for both genders among Hong Kong Chinese children and adolescents. In order to improve the diagnosis accuracy of childhood obesity, either cut-off values of body weight and height-based definitions of childhood obesity should be revised to increase the sensitivity or the possibility of using other indirect methods of estimating the %BF should be explored.

The association between breastfeeding and childhood obesity: a meta-analysis

Background

The increase in childhood obesity is a serious public health concern. Several studies have indicated that breastfed children have a lower risk of childhood obesity than those who were not breastfed, while other studies have provided conflicting evidence. The objective of this meta-analysis was to investigate the association between breastfeeding and the risk of childhood obesity.

Methods

The PubMed, EMBASE and CINAHL Plus with Full Text databases were systematically searched from start date to 1^st August 2014. Based on the meta-analysis, pooled adjusted odds ratio (AOR) and 95% confidence interval (CI) were calculated. I² statistic was used to evaluate the between-study heterogeneity. Funnel plots and Fail-safe N were used to assess publication bias and reliability of results, and results from both Egger test and Begg test were reported.

Results

Twenty-five studies with a total of 226,508 participants were included in this meta-analysis. The studies’ publication dates ranged from 1997 to 2014, and they examined the population of 12 countries. Results showed that breastfeeding was associated with a significantly reduced risk of obesity in children (AOR = 0.78; 95% CI: 0.74, 0.81). Categorical analysis of 17 studies revealed a dose-response effect between breastfeeding duration and reduced risk of childhood obesity.

Conclusion

Results of our meta-analysis suggest that breastfeeding is a significant protective factor against obesity in children.

Cholecystectomy in English children: evidence of an epidemic (1997-2012)

BACKGROUND/PURPOSE

The purpose of this study was to calculate the incidence of cholecystectomy among children aged ≤ 16 in England between 1997 and 2012 and to assess trends in risk factors.

METHODS

A nationwide retrospective cohort study using the Hospital Episode Statistics Database for episodes of cholecystectomy in children aged ≤ 16 was performed. Age and sex-specific annual incidence rates were derived using Office of National Statistics mid-year population estimates. Trends in the observed case mix were tested using univariable linear regression.

RESULTS

2808 paediatric cholecystectomies were identified. The incidence of cholecystectomy increased from 0.78/100,000 to 2.7/100,000 (P<0.0001). Sex-specific incidences increased from 1.1 to 4.36/100,000 (P<0.0001) among girls and from 0.48 to 1.13/100,000 (P<0.0001) among boys. There were significant changes in case mix, with an increasing proportion of female cases (69% to 79%, P=0.02), an increase in cases of white ethnicity (48% to 77%, P<0.0001), but only a modest increase in those with a diagnosis of sickle cell anaemia (4% to 6%, P=0.02), and no significant increase in other haemolytic anaemias.

CONCLUSIONS

There has been a three-fold increase in the incidence of paediatric cholecystectomy in England since 1997, with a particular rise among white females. Although data on BMI were not available, the observed effect may be a consequence of increasing levels of teenage obesity.

Quantitative analysis and comparison of BMI among Han, Tibetan, and Uygur university students in Northwest China

Objectives. To fully analyze and compare BMI among Han, Tibetan, and Uygur university students, to discuss the differences in their physical properties and physical health, and thus to provide some theoretical suggestions for the improvement of students' physical health. Methods. The cross-sectional random cluster sampling was used to investigate 10103 Han, Tibetan, and Uygur university students, aged 20–24 in Northwest China, and their height and weight were measured to calculate BMI. The BMI classification criteria for Chinese established by Work Group on Obesity in China (WGOC) were used for screening. Results. Han, Tibetan, and Uygur university students show low obesity rates but high overweight rates. Han, Tibetan, and Uygur university students present a high rate of underweight, normal weight, and overweight, respectively. Female Han students show higher underweight and normal weight rates, but lower overweight and obesity rates, than male Han students. Female Tibetan students show higher normal weight rate, but lower overweight and obesity rates, than male Tibetan students. BMI increases with age for male students but decreases with age for female students. Male Uygur students show higher obesity rate than female Uygur students. Tibetan and Uygur university students have higher BMI than other minorities in South China.

Bariatric surgery for obese children and adolescents: a systematic review and meta-analysis

The number of obese young people continues to rise, with a corresponding increase in extreme obesity and paediatric-adolescent bariatric surgery. We aimed to (i) systematically review the literature on bariatric surgery in children and adolescents; (ii) meta-analyse change in body mass index (BMI) 1-year post-surgery and (iii) report complications, co-morbidity resolution and health-related quality of life (HRQoL). A systematic literature search (1955-2013) was performed to examine adjustable gastric band, sleeve gastrectomy, Roux-en-Y gastric bypass or biliopancreatic diversions operations among obese children and adolescents. Change in BMI a year after surgery was meta-analysed using a random effects model. In total, 637 patients from 23 studies were included in the meta-analysis. There were significant decreases in BMI at 1 year (average weighted mean BMI difference: -13.5 kg m(-2) ; 95% confidence interval [CI] -14.1 to -11.9). Complications were inconsistently reported. There was some evidence of co-morbidity resolution and improvements in HRQol post-surgery. Bariatric surgery leads to significant short-term weight loss in obese children and adolescents. However, the risks of complications are not well defined in the literature. Long-term, prospectively designed studies, with clear reporting of complications and co-morbidity resolution, alongside measures of HRQol, are needed to firmly establish the harms and benefits of bariatric surgery in children and adolescents.

Simulation models of obesity: a review of the literature and implications for research and policy

Simulation models (SMs) combine information from a variety of sources to provide a useful tool for examining how the effects of obesity unfold over time and impact population health. SMs can aid in the understanding of the complex interaction of the drivers of diet and activity and their relation to health outcomes. As emphasized in a recently released report of the Institute or Medicine, SMs can be especially useful for considering the potential impact of an array of policies that will be required to tackle the obesity problem. The purpose of this paper is to present an overview of existing SMs for obesity. First, a background section introduces the different types of models, explains how models are constructed, shows the utility of SMs and discusses their strengths and weaknesses. Using these typologies, we then briefly review extant obesity SMs. We categorize these models according to their focus: health and economic outcomes, trends in obesity as a function of past trends, physiologically based behavioural models, environmental contributors to obesity and policy interventions. Finally, we suggest directions for future research.

Antropometria como ferramenta de avaliação do estado nutricional coletivo de adolescentes

A antropometria tem sido apontada como o parâmetro mais indicado para avaliar o estado nutricional coletivo. A avaliação nutricional coletiva de adolescentes possui uma dinâmica muito peculiar por se tratar de um momento de intensas mudanças fisiológicas e psicossociais, diretamente associadas à dinâmica nutricional deste grupo. O acompanhamento dessa dinâmica e de suas variáveis intervenientes e interativas é, portanto, um tema de discussão extremamente relevante. Esta revisão tem por objetivo apresentar as aplicações de parâmetros antropométricos à avaliação do estado nutricional de adolescentes. Conclui-se que, enquanto não houver metodologia simples de avaliação da composição corporal, para estudos epidemológicos deve-se manter o uso do índice de massa corporal, associado ou não às variáveis de dobra cutânea e perímetros. Apesar das dificuldades e limitações, as evidências apontam para uma fundamental incorporação das informações sobre a maturação sexual à avaliação do estado nutricional coletivo de adolescentes. Além disso, as investigações devem atentar mais aos parâmetros de definição da população que estará sendo estudada, cuidando, para permitir a comparação entre os estudos.

Screening for body-weight disorders in Nigerian children using contrasting definitions

Several indices for body-weight disorders exist in scientific literature, but it is inconclusive whether or not they can yield comparable results when applied to Nigerian children. The prevalence of weight disorders in Nigerian children was examined using the Centre for Disease Control and Prevention (CDC) body mass index (BMI) for age charts and the International Obesity Task Force's (IOTF) age- and sex-specific BMI cut-off points. Participants were 2015 pupils (979 boys and 1036 girls) aged 9-12 years, attending 19 public primary schools in Makurdi, Nigeria. Stature and body mass were measured using standard techniques. Results were analysed using student t-test and Chi-squared statistics, with the probability level set at <or=0.05. CDC's BMI charts categorized 2.1%, 1.6% (boys) and 3.2%, 2.8% (girls) as overweight and obese respectively. Corresponding data for the IOTF's BMI charts were 1.7%, 0.9% (boys) and 2.6%, 2.0% (girls). CDC cut-off points indicated higher prevalence of overweight and obesity, thus suggesting the need for a single definition for evaluating measurements of body mass-for-stature in the children. However, more disconcerting is the fact that CDC charts showed a high prevalence of underweight for the boys (87.1%) and girls (79.7%). Prevalent underweight conditions in our sample need urgent intervention. The IOTF method is limited in its utility to identify children who are underweight and may be at risk of growth faltering.

Genomic insights into early-onset obesity

The biological causes of childhood obesity are complex. Environmental factors, such as massive marketing campaigns for food leading to over-nutrition and snacking and the decline in physical activity, have undoubtedly contributed to the increased prevalence of overweight and obesity in children, but these cannot be considered as the only causes. Susceptibility to obesity is also determined to a great extent by genetic factors. Furthermore, molecular mechanisms involved in the regulation of gene expression, such as epigenetic mechanisms, can increase the risk of developing early-onset obesity. There is evidence that early-onset obesity is a heritable disorder, and a range of genetic factors have recently been shown to cause monogenic, syndromic and polygenic forms of obesity, in some cases interacting with environmental exposures. Modifications of the transcriptome can lead to increased adiposity, and the gut microbiome has recently been shown to be key to the genesis of obesity. These new genomic discoveries complement previous knowledge on the development of early-onset obesity and provide new perspectives for research on the complex molecular and physiological mechanisms involved in this disease. Personalized preventive strategies and genomic medicine may become possible in the near future.

The validity of BMI as an indicator of body fatness and risk among children

PURPOSE OF REVIEW

Although the prevalence of childhood obesity, as assessed by BMI (kg/m(2)), has tripled over the last 3 decades, this index is a measure of excess weight rather than excess body fatness. In this review we focus on the relation of BMI to body fatness and health risks, particularly on the ability of BMI for age >or=95th Centers for Disease Control and Prevention [CDC] percentile to identify children who have excess body fatness. We also examine whether these associations differ according to race/ethnicity and whether skinfold and circumference measurements provide additional information on body fatness or health risks.

RESULTS

The accuracy of BMI varies according to the degree of body fatness. Among relatively fat children, BMI is a good indicator of excess adiposity, but differences in the BMIs of relatively thin children can be largely due to fat-free mass. Although the accuracy of BMI in identifying children with excess body fatness depends on the chosen cut points, we have found that a high BMI-for-age has a moderately high (70%-80%) sensitivity and positive predictive value, along with a high specificity (95%). Children with a high BMI are much more likely to have adverse risk factor levels and to become obese adults than are thinner children. Skinfold thicknesses and the waist circumference may be useful in identifying children with moderately elevated levels of BMI (85th to 94 th percentiles) who truly have excess body fatness or adverse risk factor levels.

CONCLUSION

A BMI for age at >or=95th percentile of the CDC reference population is a moderately sensitive and a specific indicator of excess adiposity among children.

Self-esteem in a clinical sample of morbidly obese children and adolescents

AIM

To study self-esteem in clinical sample of obese children and adolescents.

METHODS

Obese children and adolescents aged 8-19 years (n = 107, mean age 13.2 years, mean BMI 32.5 [range 22.3-50.6], mean BMI z-score 3.22 [range 2.19-4.79]; 50 boys and 57 girls) were referred for treatment of primary obesity. Self-esteem was measured with a validated psychological test with five subscales: physical characteristics, talents and skills, psychological well-being, relations with the family and relations with others. A linear mixed effect model used the factors gender and adolescence group, and the continuous covariates: BMI z-scores, and BMI for the parents as fixed effects and subjects as random effects.

RESULTS

Age and gender, but neither the child's BMI z-score nor the BMI of the parents were significant covariates. Self-esteem decreased (p < 0.01) with age on the global scale as well as on the subscales, and was below the normal level in higher ages in both genders. Girls had significantly lower self-esteem on the global scale (p = 0.04) and on the two subscales physical characteristics (p < 0.01) and psychological well-being (p < 0.01).

CONCLUSION

Self-esteem is lower in girls and decreases with age. In treatment settings special attention should be paid to adolescent girls.

The Children's Body Image Scale: reliability and use with international standards for body mass index

OBJECTIVE

To test the reliability of the Children's Body Image Scale (CBIS) and assess its usefulness in the context of new body size charts for children.

METHOD

Participants were 281 primary schoolchildren with 50% being retested after 3 weeks. The CBIS figure scale was compared with a range of international body mass index (BMI) reference standards.

RESULTS

Children had a high degree of body image dissatisfaction. The test-retest reliability of the CBIS was supported.

CONCLUSIONS

The CBIS is a useful tool for assessing body image in children with sound scale properties. It can also be used to identify the body size of children, which lies outside the healthy weight range of BMI.

Update on obesity

Endocrinologists have unique skills in evaluating and caring for patients with metabolic diseases. As such, they have a special role to play within the organizations in which they work as leaders in the approach to managing obese patients. Recent epidemiological data demonstrate that the prevalence of obesity is beginning to plateau. However, the rate of severe obesity in adults and the prevalence of overweight among children continue to grow, suggesting that in the future there will be an increasing burden of obesity-related illnesses. A number of recent studies have identified a number of novel mechanisms that predispose to obesity including several newly identified genes, the role of intestinal microflora, and even social networks. The selection of treatment for obese patients remains a complex issue. Recent studies demonstrate that a range of dietary approaches including the Atkins diet can provide modest weight loss, although the key feature appears to be adherence in the dietary strategy. High levels of physical activity appear to be necessary to maintain a reduced state, although modest increases in activity improve fitness. Although the new understanding of biology of weight regulation has provided a wide range of potential drug targets, available pharmacotherapy options remain limited although a number of potential targets show promise. Recent data provides the most enthusiasm for surgical treatment of obesity. Several recent studies demonstrate a reduction in mortality and dramatic benefits in diabetes in obese patients treated surgically. Questions remain as to the best surgical approach and the cost effectiveness. Research advances in obesity continue to move at a rapid pace and raise hopes for more effective management strategies in the future.

No evidence for association between BMI and 10 candidate genes at ages 4, 7 and 10 in a large UK sample of twins

Background

Over the last decade, associations between Body Mass Index (BMI) and a variety of candidate genes have been reported, but samples have almost all been limited to adults. The purpose of the present study was to test the developmental origins of some of these associations in a large longitudinal sample of children.

Methods

For 10 single-nucleotide polymorphisms (SNPs) in candidate genes reported to be associated with BMI in adults, we examined associations with BMI in a sample of 5000 children (2500 twin pairs) with BMI data at 4, 7 and 10 years. Association analyses were performed using the Quantitative Transmission Disequilibrium Test and we corrected for multiple testing using the False Discovery Rate.

Results

Despite having 80% power to detect associations that account for as little as 0.2% of the variance of BMI, none of the 10 SNPs were significantly associated with BMI at any age, although two SNPs showed trends in the expected direction.

Conclusion

The lack of association for these ten previously reported associations, despite our large sample size, is typical of associations between candidate genes and complex traits. However, some of the reported SNP associations with BMI might emerge as we continue to follow the sample into adolescence and adulthood. This report highlights the importance of developmentally appropriate candidate genes.

Public health interventions for addressing childhood overweight: analysis of the business case

We investigated the appropriateness of basing childhood obesity interventions on expectations of return on investment (ROI). We show that excess weight is indeed associated with greater medical expenditures even among children and adolescents. However, under current best practices, it is unlikely that interventions will be able to meet the level of effectiveness required at a low enough implementation cost to show positive ROI. The merits of childhood obesity interventions should be based on their ability to efficiently control weight and improve health compared with alternative uses for available resources. They should not be based on the potential for short-term financial savings.

Gendered dimensions of obesity in childhood and adolescence

Background

The literature on childhood and adolescent obesity is vast. In addition to producing a general overview, this paper aims to highlight gender differences or similarities, an area which has tended not to be the principal focus of this literature.

Methods

Databases were searched using the terms 'obesity' and 'child', 'adolescent', 'teenager', 'youth', 'young people', 'sex', 'gender', 'masculine', 'feminine', 'male', 'female', 'boy' and 'girl' (or variations on these terms). In order to limit the potential literature, the main focus is on other reviews, both general and relating to specific aspects of obesity.

Results

The findings of genetic studies are similar for males and females, and differences in obesity rates as defined by body mass index are generally small and inconsistent. However, differences between males and females due to biology are evident in the patterning of body fat, the fat levels at which health risks become apparent, levels of resting energy expenditure and energy requirements, ability to engage in certain physical activities and the consequences of obesity for the female reproductive system. Differences due to society or culture include food choices and dietary concerns, overall physical activity levels, body satisfaction and the long-term psychosocial consequences of childhood and adolescent obesity.

Conclusion

This review suggests differences between males and females in exposure and vulnerability to obesogenic environments, the consequences of child and adolescent obesity, and responses to interventions for the condition. A clearer focus on gender differences is required among both researchers and policy makers within this field.

An overview of pediatric obesity

Pediatric obesity is increasing worldwide and disproportionately affects the economically and socially disadvantaged. Obese children are at risk of developing the (dys)metabolic syndrome, insulin resistance, early-onset type 2 diabetes mellitus, polycystic ovarian syndrome, hypertension, hyperlipidemia, and obstructive sleep apnoea. Those with diabetes may have mixed features of type 1 and type 2 diabetes mellitus. Pediatric obesity is the result of persistent adverse changes in food intake, lifestyle, and energy expenditure. It may be because of underlying a genetic syndrome or a conduct disorder. Children living in urban settings often lack safe, affordable, and accessible recreational facilities. Tight educational schedules mean less free time, while computer games and television have become preferred recreational activities. More families are eating out or eating take-out meals and processed foods at home because of pressures of work and time constraints. Consumer advertising targeted at children and the ready availability of vending machines encourage unwise food choices. Some children eat excessively because they are depressed, anxious, sad, or lonely. Often families and obese children are aware of the need for healthy eating and exercise but are unable to translate knowledge into weight loss. Population-based measures such as public education, school meal reforms, child-safe exercise friendly environments, and school-based and community-based exercise programs have been shown to be successful to varying degrees, but there remain individuals who will need special help to overcome obesity. Overeating (e.g. binge eating) may be a manifestation of disordered coping behavior but may also be because of defects in the neural and hormonal control of appetite and satiety. New pharmacological approaches are targeting these areas. We need a coordinated approach involving government, communities, and healthcare providers to provide a continuum of population-based interventions, focused screening, and personalized multidisciplinary interventions for the obese child and family.

Measurement and definitions of obesity in childhood and adolescence: a field guide for the uninitiated

This paper aims to guide readers embarking on the complex literature in respect of childhood and adolescent obesity. It opens with a discussion of definitions of 'obesity' based on overall fat levels and the significance of fat distribution. This is followed by simple descriptions of the various techniques used to measure fat, including density-based, scanning, bioelectrical impedance and anthropometric methods. The paper then turns to 'overweight' and the measurement of weight in relation to height, particularly via body mass index (BMI). While it is a relatively simple measure and a valuable tool, BMI has several disadvantages, which are described. These include a lack of consensus on which values should be used to define 'overweight' or 'obese', with the result that the literature contains a confusing multiplicity of child and adolescent obesity rates.

Methodological limitations in measuring childhood and adolescent obesity and overweight in epidemiological studies: does overweight fare better than obesity?

Objectives

International definitions of childhood obesity based on body mass index (BMI) are intended to be used for international comparisons of obesity prevalence. In general, they are not appropriate to be used in clinical practice. The objective of this study is to compare international-ecological vs. national-clinical reference data of obesity in Spain, as well as to describe trends.

Design

Cross-sectional study from a representative national random sample of Spanish children and youth conducted between 1998 and 2000. Prevalence estimates of obesity in a national random sample of Spanish children and youth are presented in this paper, defined by age- and sex-specific BMI national reference standards for the 85th percentile (overweight) and 95th percentile (obesity), as well as by Cole et al. criteria. The study protocol included personal data, data on education and socio-economic status for the family and anthropometric measurements.

Setting

Population-based study set in Spain.

Subjects

A random sample of 3534 individuals, aged 2–24 years.

Results

Prevalence of obesity using national reference data was higher (15.3%) than using international data (5.8%), but overweight rates were similar. Agreement observed for both definitions was low for obesity but higher for overweight. Obesity trends among children and adolescents in Spain show increasing patterns in boys but not in girls.

Conclusions

Results indicate the need to standardise the definitions of obesity and overweight in childhood and recommend the use of overweight due to the greater degree of agreement observed among the different methods used. The IOTF reference method underestimates obesity rates in Spanish schoolchildren.

Prevalence of overweight and obesity in Irish school children, using four different definitions

OBJECTIVE

To determine the prevalence of overweight and obesity in Irish children using four different weight-for-height methods and to examine secular trends from previous national data.

DESIGN

A cross-sectional survey. Weight and height were measured according to standard procedures and used to determine the prevalence of overweight and obesity using four weight-for-height methods of assessment, actual relative weight, the Centers for Disease Control and Prevention body mass index (BMI) for age charts for boys and girls, the BMI reference curves for the UK 1990 and the International Obesity Task Force age- and sex-specific BMI cutoffs.

SETTING

The survey was carried out between 2003 and 2004 in the Republic of Ireland.

SUBJECTS

Random representative sample of 596 children aged 5-12 years.

RESULTS

The prevalence of overweight and obesity in Irish children is high, but varies considerably with each method. The prevalence of obesity in boys ranged from 4.1 to 11.2 % and in girls from 9.3 to 16.3%. Between 1990 and 2005, depending on the method used, there was a two-to-fourfold increase in obesity in children aged 8-12 years.

CONCLUSION

It is evident given the variation displayed in the prevalence of obesity when using the different methods, that there is a discernible need for a single definition to identify the obese child in Ireland. The findings show a high prevalence of overweight and obesity in Irish school children and the increase in the prevalence of obesity over the last 15 years highlights this growing public health issue.