Childhood Obesity

Childhood obesity is an issue of serious medical and social concern. In developing countries including India, it is a phenomenon seen in higher socioeconomic strata due to the adoption of a western lifestyle. Consumption of high calorie food, lack of physical activity and increased screen time are major risk factors for childhood obesity apart from other genetic, prenatal factors and socio-cultural practices. Obese children and adolescents are at increased risk of medical and psychological complications. Insulin resistance is commonly present especially in those with central obesity and manifests as dyslipidemia, type 2 diabetes mellitus, impaired glucose tolerance, hypertension, polycystic ovarian syndrome and metabolic syndrome. Obese children and adolescents often present to general physicians for management. The latter play a key role in prevention and treatment of obesity as it involves lifestyle modification of the entire family. This article aims at discussing the approach to diagnosis and work-up, treatment and preventive strategies for childhood obesity from a general physician’s perspective.     

Dysmetabolic syndrome in childhood and adolescence

The dysmetabolic syndrome, consisting of dyslipidaemia, hypertension, hyperinsulinaemia and central obesity, has been well recognized as a major risk for cardiovascular disease in adults. Although the clustering of cardiovascular risk factors has also been identified in childhood, the occurrence of full-blown dysmetabolic syndrome at younger ages has only recently been investigated. In this article we attempted an overview of the data for children and adolescents, focused on the mechanisms and natural history of the disease, the prevalence among paediatric populations, the assessment and the treatment approaches.

Conclusion: There is substantial evidence that the dysmetabolic syndrome has its origins in childhood. In the face of the epidemic increase of obesity in children and adolescents, the development of effective screening and preventive strategies would be a major challenge for paediatricians.     

Addressing obesity in the first 1000 days in high risk infants: Systematic review

Early intervention is critical for addressing the challenge of childhood obesity. Yet many preventive interventions do not target infants most at risk of future overweight or obesity. This systematic review examines interventions delivered before 2 years that aim to ameliorate excess weight gain among infants at high risk of overweight or obesity, due to sociodemographic characteristics, parental weight or health status, infant feeding or health behaviours. We searched six databases for interventions: (a) delivered before age two, (b) specifically aimed at infants at high risk of childhood obesity and (c) that reported outcomes by weight status beyond 28 days. The search identified over 27,000 titles, and 49 papers from 38 studies met inclusion criteria: 10 antenatal interventions, 16 postnatal and 12 conducted both before and after birth. Nearly all targeted infant and/or maternal nutrition. Studies varied widely in design, obesity risk factors, outcomes and quality. Overall, nine interventions of varying quality reported some evidence of significantly improved child weight trajectory, although effects tended to diminish over time. Interventions that improved weight outcomes tended to engage parents for a longer period, and most offered health professional input and support. Two studies of limited quality reported significantly worse weight outcomes in the intervention group.     

The development of obesity in childhood

Multiple factors appear to influence and promote the development of obesity: The importance of genetic factors has been demonstrated in some studies, however, it is very difficult to distinguish between environmental and genetic influences. Independently, increased birthweight, massive weight gain in the first months after birth and overweight of the mother or of both parents seem to be risk factors, which are able to promote the development of childhood obesity. In the past few years more attention has been paid to psychological factors and their influence on appetite, physical activity and energy balance. Whether metabolic changes on cellular and microcellular basis can cause obesity is not sufficiently known until now. Nutrition in early childhood and fat cell hyperplasia and hypertrophia induced by nutritional factors probably do not imply persistence of obesity but may promote obesity and worsen the prognosis of therapy. Due to the fact that a high percentage of obese adolescents remain obese in adulthood, and due to the poor results in the treatment of obesity as well as the association of overweight with an increased risk for morbidity and mortality an effective therapy and prevention of obesity even during childhood seem to be of great importance.     

Ethnic issues in the epidemiology of childhood obesity

Childhood obesity may be seen as a marker for high-risk dietary and physical inactivity practices. Recent increases in the prevalence of overweight and obesity among American children are not limited to one age, gender, or ethnic group, which suggests that unique behaviors of the members of various racial or ethnic subgroups of the population are unlikely to be the major contributing factors. Rather, it seems that environmental changes promoting increased energy intake and decreased energy output are occurring and have widespread impact on children from various backgrounds. Although no ethnic group is immune from the current shift in energy balance, differential rates of overweight seem to exist among ethnic groups. National probability samples of African-American, Hispanic, and white children in the United States provide clear evidence that white children are at lower risk for childhood overweight than are African-American or Hispanic children. Of concern is the lack of national data on the prevalence of overweight and obesity for Native-American and Asian-American groups. Also of concern is the aggregation of racial and ethnic subgroups, which may render prevalence rates meaningless. This possibility is clearly true with some surveys of weight status that combine diverse populations, such as Asians and Pacific Islanders, into one group. The high rates of obesity in African-American, Hispanic, and Native-American children are of concern. Although parental SES is associated inversely with childhood obesity among whites, higher SES does not seem to protect African-American and Hispanic children against obesity. In these groups, childhood obesity does not seem to be associated significantly with parental income and education. Health consequences of childhood obesity include a higher prevalence of type 2 diabetes and an increased risk for adverse levels of lipids, lipoproteins, and blood pressure. The effects of recently reported unprecedented levels of childhood overweight on subsequent risk for obesity in middle age are not known until future longitudinal data can be collected. It seems likely, however, that future health consequences of current early and severe childhood obesity will be staggering. Funding for adult follow-up of longitudinal studies of high-risk African American, Hispanic, and Native-American children is needed urgently to provide information on the long-term effects of childhood obesity. Halting the obesity epidemic is a formidable task, but the success in recent decades of drastically reducing childhood undernutrition offers hope and should spur similar action and leadership efforts. Promotion of efforts to reduce excess caloric intake with efforts to increase energy expenditure should receive paramount attention in the design of health programs. Given the relatively few published obesity-prevention and treatment studies that are designed to address specific cultural issues, it is important to promote the development of culturally appropriate intervention strategies that are shown to be effective among youth of diverse backgrounds. Although the dietary and activity goals will be similar, parental, family, and community messages and techniques grounded in cultural traditions and norms will be different for each ethnic group. This approach is crucial in the United States, a country with an increasingly diverse population.     

Sleep and obesity in children and adolescents

The purpose of this review is to provide a comprehensive update of epidemiologic studies that have assessed the association between sleep and obesity risk. Data suggest that short sleep is associated with an increased risk for being or becoming overweight/obese or having increased body fat. Late bedtimes are also a risk factor for overweight/obesity. Findings also suggest that changes in eating pathways may lead to increased body fat. Future experimental studies are needed to enhance our understanding of the underlying mechanisms through which sleep may play a role in the development and maintenance of childhood obesity.     

Obesity, metabolic syndrome, and cardiovascular disease

Early childhood overweight and obesity have alarmingly increased over the years. Adulthood obesity is a well demonstrated significant independent predictor of cardiovascular risk (CVR) and/or mortality, which predisposes to the major components of metabolic syndrome (MS). Evidence of MS in obese children has been also reported associated with biochemical and inflammatory factors that affect vascular physiologic function. Assessment of vascular function can be measured noninvasively in children allowing early detection of endothelial dysfunction and severe increase of arterial stiffness before clinical manifestations of atherosclerosis. Impairment of endothelial function related to the severity of obesity and to the degree of insulin resistance is considered as a condition that confers a premature atherogenicity status and is linked to adult conventional cardiovascular risk factors. Adipose tissue factors that interfere with insulin action and endothelial cell function have also been identified as major precursors of CVR factors. The metabolic and cardiovascular consequences of childhood obesity are well demonstrated and have a major impact on the development of atherosclerosis and lifetime CVR. The development of programs involving both diet and exercise for children with overt overweight/obesity appears to be essential to improve vascular function and metabolic disorders. Such interventions should be complemented by a primary prevention against childhood obesity.     

Overweight and obesity and their associated factors in adolescents in Tehran, Iran, 2004–2005

Overview Obesity is a significant health crisis around the world. Of great concern are the data pointing to the recent increase in the prevalence of obesity irregardless of age group and country. Overweight and obesity in adolescence are markers of overweight and obesity in adults, respectively. Very little data are currently available on the prevalence of childhood obesity in Iran, and more research on the risk factors is required before preventive public health programs can be formulated and put into practice.Objective The objective of this study was to quantify the prevalence of overweight and obesity and their associated factors in adolescent children living in Tehran.Materials and methods During a multistage stratified cluster sampling, 2900 students (1200 males and 1700 females) aged 11–17 years were selected from 20 secondary schools in the school year of 2004–2005. A questionnaire was filled, and weight and height were measured.Discussions and conclusions The body mass index (BMI) was calculated and adjusted for age and sex. Prevalences of overweight and obesity were 17.9 and 7.1%, respectively. BMI increased with age, and it was higher in those who had lower levels of physical activity. Age at menarche was negatively associated with BMI. There was no relationship between macro- and micronutrient intake and overweight and obesity. This study highlights the high prevalence of overweight and obesity in adolescent children in Tehran.     

Risk factors for obesity in 7-year-old European children: the Auckland Birthweight Collaborative Study.

OBJECTIVE: To identify risk factors associated with obesity in primary school children, with a particular focus on those which can be modified. To identify critical periods and growth patterns in the development of childhood obesity. METHODS: 871 New Zealand European children were enrolled in a longitudinal study at birth and data were collected at birth, 1, 3.5 and 7 years of age. Data collected at 7 years included weight, height, bioelectrical impedance analysis (BIA), television viewing time and a 24 h body movement record (actigraphy). The outcome measure was percentage body fat (PBF), which was calculated at 3.5 and 7 years using BIA. Univariate and multiple regression analyses were carried out using PBF as a continuous variable. RESULTS: Multivariable analysis found maternal overweight/obesity, maternal age, female gender, sedentary activity time and hours of television viewing to be independently associated with PBF at 7 years. Growth variables (birth weight, rapid weight gain in infancy, early (1-3.5 years) and middle childhood (3.5-7 years)) were also independently associated with adiposity at 7 years. There was a strong correlation between PBF at 3.5 years and PBF at 7 years. CONCLUSIONS: Many primary school aged children start on the trajectory of obesity in the preschool years, which suggests interventions need to start early. Maternal overweight/obesity, television watching, sedentary activity time and rapid weight gain in infancy, early and middle childhood are risk factors for childhood obesity, and are all potentially modifiable.     

International epidemic of childhood obesity and television viewing

Childhood obesity is one of the most serious global public health challenges of the 21st century. The prevalence of this problem has increased at an alarming rate in many countries. The main causes of childhood obesity are; sedentary lifestyle, unhealthy eating patterns, genetic factors, socio-economic status, race/ethnicity, media and marketing, and the physical environment. Children are clearly being targeted as a receptive market by the manufacturing industry. Undoubtedly, television provides one of the most powerful media through which products can be advertised. Furthermore, food advertising accounted for the largest percentage of these advertisements in virtually all countries. Detailed nutritional analysis of food advertisements identified that up to 90% of food products have a high fat, sugar or salt content. Therefore TV viewing is recently identified as one of the risk factors contributing to development of childhood obesity by several mechanisms. This review provides some facts and figures about the global trend of rising obesity among children, amount and content of television and especially food advertisements being watched by children and its possible mechanisms how to cause adverse effects on children's health and contribute to childhood obesity.     

Clustering of coronary heart disease risk factors among obese children

Recent secular trends have resulted in large numbers of very overweight children who are at increased risk for type 2 diabetes mellitus and for various coronary heart disease risk factors, including adverse levels of lipids, insulin, and blood pressure. Furthermore, severe overweight in childhood is associated with risk factor clustering and with the initial stages of atherosclerosis. There are also several adult consequences of childhood obesity, including coronary heart disease, type 2 diabetes mellitus, and premature mortality. The difficulties in preventing and reversing obesity, along with the frequent non-adherence of adolescents to lifestyle changes and medical treatment, will complicate treatment and prevention efforts.     

A meta-analysis of the effect of high weight on asthma.

BACKGROUND: Prevalence rates for both overweight and asthma have been increasing among children in developed countries over the past two decades. Some recent studies have postulated a causal relation between these but have lacked power to form a definitive conclusion. AIM: To estimate the effect of high body weight in childhood on the future risk of asthma. METHODS: Medline search (1966 to October 2004), supplemented by manual search of reference lists and grey literature. Cohort studies that examined high body weight at birth or during childhood and future outcome of asthma were included. Data from each study were extracted on exposure status, clinical outcome, and study characteristics. RESULTS: A total of 402 studies were initially identified, of which 12 met the inclusion criteria. The combined results from four studies that examined the effect of high body weight during middle childhood on the outcome of subsequent asthma showed a 50% increase in relative risk (RR 1.5, 95% CI 1.2 to 1.8). The combined results from nine studies that examined the effect of high birth weight on subsequent asthma had a pooled RR of 1.2 (95% CI 1.1 to 1.3). There was consistency among the results in sensitivity analyses examining studies containing only estimates of odds ratios, studies containing only the outcome of physician diagnosis of asthma, and studies including all definitions of high body weight. CONCLUSIONS: Children with high body weight, either at birth or later in childhood, are at increased risk for future asthma. Potential biological mechanisms include diet, gastro-oesophageal reflux, mechanical effects of obesity, atopy, and hormonal influences. Further research might elucidate the causal pathway, which could improve our understanding of the pathophysiology of asthma and perhaps lead to knowledge of potential preventive interventions.     

Physical activity and cardiovascular health in children

The rapid growth in the prevalence of obesity in children and the tracking of obesity from childhood to adulthood can predispose children to type 2 diabetes and CVD at an early age. Strategies to prevent obesity and its complications are of urgent importance. In view of the enormous cardio-protective role of physical activity, pediatricians should implement more intensely preventive strategies based on physical activity, diet, and behavior. This approach is crucial as an effective form of prevention of development of diabetes and CVD, as well as a therapy for children with risk factors for CVD. However, this is a complex task and requires a unified approach that involves environmental, behavioral, cultural, economic, legislative, and physiological factors, as well as a favorable environment that promotes physical activity along with healthy dietary habits.     

Epidemiology of childhood obesity in Europe

At present, estimation of the prevalence and secular trends in paediatric obesity in Europe is severely hampered by methodological problems in the definition of obesity and the paucity of data sets that mirror the demographic, cultural and socioeconomic composition of the European population. The available cross-sectional data, however imperfect, suggest that there are complex patterns in prevalence which vary with time, age, sex and geographical region. Overall, the prevalence of obesity in young children is relatively low compared to adolescents. Gender differences in prevalence are inconsistent. The highest rates of obesity are observed in eastern and southern European countries and even within countries there may be marked variability in the rates of obesity. It is not clear whether the trends in paediatric obesity are a simple consequence of an overall increase in fatness in Europe or whether there may be sub-groups of children who, at certain ages, are either particularly susceptible to environmental challenges or are selectively exposed to such challenges. The respective contributions of dietary energy intake and patterns of physical activity to the aetiology of childhood obesity present a confused and confusing picture. Changing demographic and social circumstances throughout Europe are linked to childhood obesity but it is highly unlikely that these interact in similar ways in the genesis of obesity in different individuals and population groups. Conclusion At present, our limited understanding of the variability in susceptibility to obesity in European children and adolescents provides powerful justification for the development of preventive strategies which are population based rather than selectively targeted at high-risk children.     

Nutrition interventions in childhood for the prevention of chronic diseases in adulthood

As it becomes increasingly evident that the seeds of many adult disorders are planted in childhood, it is important that pediatric care providers 1) recognize risk factors for adult disease in children and 2) institute effective interventions. Many adult medical conditions are significantly related to or influenced by nutritional factors. This review evaluates three areas in preventive and therapeutic pediatric nutrition: obesity, lipid disorders, and osteoporosis.     

Stratégies de prévention de l’obésité chez l’enfantPrevention strategies of childhood obesity

Considering the high prevalence and the increasing trends, obesity is now considered as a public health problem in numerous countries. The main aim of the National Program of Nutrition and Health is to stop the increasing prevalence of childhood obesity. In this frame work, a group of experts has established a new presentation of the corpulence curves, adapted for clinical practice, to define normal weight and obesity. Weight status is now currently assessed on the basis of weight and height measurements, after computing the Quetelet index or body mass index (BMI) corresponding to weight (m) divided by square of height (weight/height2). As body proportion varies during growth, age must be taken into account. Various curves were published. In 1982, based on the French sample of the international growth study, BMI curves were published. They were revised in 1991. The third and 97th centiles define the normal weight range. Overweight is defined by BMI values greater than the 97th centile. In the year 2000, a new international definition was established. Two centiles were constructed to define overweight and obesity. The new BMI charts adapted for clinical practice, proposed by the French National program of nutrition and health, include the French reference curves plus the centile defining obesity in the international definition. Thus, in the new French charts, the area above the 97th centile is split in two levels (degree 1 obesity and degree 2 obesity). Drawing the BMI curve for each child, like drawing weight and height curves, is a simple act which can be done routinely. The age at adiposity rebound (an indicator predicting the risk of adult obesity) can be read from the curve. It allows to identify an early phase of obesity development, even at the time when overweight is not yet clinically visible. When obesity appears clearly, the identification is easy. The use of BMI curves is particularly useful in two situations: (1) in very young overweight children, the curves allow to identify children who have a real risk of developing obesity. (2) By the age of 6 years, when due to normal physiological variations, clinical assessment can be misleading. The BMI curves allow to identify children at risk. When a child is identified as having a real risk of obesity, simple preventive measures, adapted for each subject, could avoid a development toward massive obesity, which may become difficult to reduce if managed too late.     

Secondary narcolepsy may be a causative factor of increased daytime sleepiness in obese childhood craniopharyngioma patients

Prognosis in childhood craniopharyngioma survivors hinges upon late effects such as pituitary deficiency and obesity. Observations indicate that reduced physical activity and increased daytime sleepiness might be risk factors for obesity. We analyzed the degree of daytime sleepiness in 115 childhood craniopharyngioma patients (47% obese) using the Epworth Sleepiness Scale (ESS). Thirty-five (30%) displayed increased daytime sleepiness (ESS score > 10) of whom 14 were obese (26% of obese cohort). Polysomnography (PSG) and Multiple Sleep Latency Tests (MSLT) were conducted with 10 obese patients presenting increased daytime sleepiness, with only two craniopharyngioma patients revealing a sleep related breathing disorder. Four patients had repeated episodes of SOREM (sleep onset rapid eye movement), the classic PSG criterion for narcolepsy. Three patients displayed hypersomnia. All but one patient qualified as acutely obese. We speculate that secondary narcolepsy is an exacerbating condition of childhood craniopharyngioma obesity, supported by recent reports on orexin and narcolepsy which suggest hypothalamic failure in idiopathic narcolepsy.     

全国0～6 岁儿童单纯性肥胖流行病学研究

目的 本研究旨在了解自1996年第二次全国儿童期单纯肥胖症流行学研究后10年来我国儿童期单纯肥胖症的发展特征和趋势;复核本工作组研究初期所确定的工作假设和所选择的指示参数的科学效应;修订本工作组所制定的中国儿童单纯肥胖症控制方案的科学性和可操作性.方法 选择沈阳、济南、青岛、郑州、长沙、重庆、西安、成都、深圳、海口、文昌11个城市,采取随机整群抽样的方法,共调查0～6岁儿童84 766名,代表人口1 414 220名儿童.儿童肥胖的判定标准为世界卫生组织(WHO)身高标准体重值,采用标准差计分法(Z-score),体重高于中位数1个标准差为超重、高于2个标准差为肥胖.测量体重、身长/身高、3岁以上儿童的腰围、臀围、大腿围及血压.计数、计量数据分别采用χ2检验和t检验进行分析,显著性检验水平为0.05.结果 (1)本次调查0～6 岁儿童肥胖、超重总检出率分别为7.2%、19.8%,其中男童肥胖、超重检出率分别为8.9%、22.2%,女童肥胖、超重检出率分别为5.3%、17.0%.较1996年分别增长了3.6、4.7倍,年均增长速度分别为156%和52%.肥胖、超重检出率北部高于西部,中南部居中;男童高于女童.肥胖、超重比仍处于高危水平.(2)出生后1个月儿童的平均体块指数(BMI)值＞16.5,于1个月时BMI均值达最高(17.8),之后逐渐降低,5.5岁时降至最低点(平均值15.7),然后随年龄上升,但最高BMI均值未超过18.(3)本次调查中,脂肪重聚年龄为5.5岁,较1996年后移半年.出生后前半年的脂肪重聚比(ARR1)为0.56,出生后半年(ARR2)为0.97,均处于可接受水平,且明显低于10年前的水平.(4)西部地区儿童由于身高不足,可以出现"假性超重".这既掩盖了早期线性生长不足和营养不良,又掩盖了可能产生的肥胖.(5)本次调查肥胖儿童血压高于第95百分位数的比例高达12.9%,其腰臀比大于本工作组设置的1.0的危险警戒水平者占17.2%.(6)本工作组所设立的BMI参照值及肥胖筛查界值点、脂肪重聚比/年龄等参照值及界值点、腰臀比参照值及界值点等指示参数在现场筛查和指示健康危险因素等方面是适宜、科学、实用的.结论 近10年儿童期单纯肥胖症检出率和肥胖儿童高血压率增加明显,且存在心血管高危状态,应加强儿童期单纯肥胖症的早期预防控制.     

Nutritive Einflussfaktoren auf die Entwicklung von kindlicher Adipositas und mögliche Präventionsansätze

Tremendous increases in the prevalence rates of overweight and obesity in children and adolescents require a search for possible causes and potential prevention strategies. Intrauterine and early infant nutrition are recognized as modifying factors for the development of obesity in adolescence and adulthood. Several recent investigations found that breastfeeding prevents obesity and overweight in later childhood and adolescence. However, so far no causal and definitive factors for the preventive effect could be found.Excessive fat intake during infancy and childhood is thought to play a major role in development of obesity. Typical food preferences for fatty and sweet foods paired with permanent availability and increasing inactivity predispose our society to weight gain and obesity. Preventive measures will have to take into account all possible causative factors in order to fight the disastrous consequences for the whole society.     

Langfristige Prägung der Gesundheit durch die Säuglingsernährung

The early nutrition from conception to early childhood has imprinting or programming effects on later health and disease risks. Rapid weight gain in fetal life and early childhood increases the risk of later obesity, diabetes and other non-communicable diseases (NCD). In observational cohort studies rapid weight gain from birth to 2 years old was associated with an increased risk of obesity up to adulthood. Breastfeeding is associated with less rapid weight gain in infancy than conventional infant formula nutrition. Several meta-analyses of observational studies found that breastfeeding was associated with an approximately 12–24?% reduction in the risk of obesity in later life. We investigated the early protein hypothesis, which proposes that a high protein intake in infancy leads to increased concentrations of insulinogenic amino acids, the growth factors insulin and insulin-like growth factor-1 (IGF-1) as well as greater weight gain and later obesity. The hypothesis was tested in a double blind randomized clinical trial involving 1678 term infants who received conventional infant and follow-on formulae with higher protein content or with reduced protein content during the first year of life. The reduced protein diet led to significantly reduced body weight, weight-for-length and body mass index (BMI) up to the age of 2 years and to a 2.4–2.9-fold reduction of obesity at 6 years old compared to conventional bottle feeding formulae. We concluded that infant feeding has powerful long-term programming effects, with very large effect sizes on obesity in early school age. Breastfeeding should be actively promoted, protected and supported. Infants not exclusively breastfed should receive infant formulae with reduced protein content. Unmodified cows’ milk contains three times as much protein as human milk and should be avoided as a drink in infancy.