Prevalence of obesity and associated risk factors in chinese pre school children aged 6 to 72 months old in singapore 1

PREVALENCE OF OBESITY AND ASSOCIATED RISK FACTORS IN CHINESE PRE-SCHOOL CHILDREN AGED 6 TO 72 MONTHS OLD IN SINGAPORE CHAPTER 1 1. LITERATURE REVIEW 1.1 Introduction Obesity is a condition in which there is an abnormal excessive accumulation of adipose tissue, causing negative effects to health.1,2 Obesity is primarily due to an imbalance between energy intake and energy expenditure, usually resulting from increased food intake and/or decreased physical activity. 3, 4 Although the prevalence of obesity has been steadily increasing worldwide for many years, the steep rise in the number of obese children and adolescents since 1980s5, 6 has elevated obesity to epidemic status, putting it at the top of the WHO’s Public Health agenda.7 1.1.1 Aetiology of Obesity Multiple factors such as genetics8-13 and behavioral factors14-17 may contribute to obesity. There are several reports of gene mutations associated with 1 body weight regulation. Variations in the fat mass and obesity-associated gene (FTO) show a strong and highly significant correlation with obesity but the mechanisms remains unclear.8-10 Moreover, genome-wide association studies showed that a variation in the PFKP gene involved in glycolysis is also strongly associated with obesity.8 Leptin and leptin receptor genes are two well-known factors that play a role in obesity. Polymorphism in either the leptin gene or the leptin receptor gene can produce inactive leptin or inefficient leptin action (leptin receptor dysfunction), and increased neuropeptide Y level, resulting in overweight or obesity.11-13 In the past three decades, overweight and obesity have become primary problems in Western countries. Many other countries have now adopted the Western culture and behavior and have changed their food consumption behavior because of increased availability and accessibility of fast foods and manufactured foods which are high in fat and sugar. For recreation, adults spend more time watching television, playing video games, browsing the web and other internetrelated activities. A sedentary life style combined with physical inactivity and unhealthy foods explain the growing epidemic of obesity for both young and old people.1, 14-17 1.1.2 Consequences of obesity Obesity can cause weight-related problems and even mortality.1,18 Complications of childhood obesity include high blood pressure,19,20 high 2 cholesterol,20 diabetes,21 and in later years, early heart diseases.22,23 Other comorbidities associated with childhood obesity are orthopedic problems, skin fungal infections, acanthosis nigracans, hepatic steatosis, pseudotumor cerebri and psycho-social consequences.24-26 Moreover, overweight children are more likely to remain overweight as adults.18,27,28 One of the cardiovascular risk factors of obesity is hyperlipidemia.26 The prominent sign of hyperlipidemia is central fat distribution and the symptoms are elevated serum low-density lipoprotein cholesterol (LDL) and triglycerides (TG) but lowered high-density lipoprotein cholesterol (HDL).20, 25 The mechanism is the same as in adults. Obese children possess increased free fatty acids in their blood circulation resulting from lipolysis and hyperinsulinemia due to increased intake of food.25 Free fatty acids stimulate the hepatic synthesis of LDL and TG which can lead to fat deposition and obesity.25 Non-insulin dependent diabetes mellitus is another complication. Increased body fat mass cause increased basal insulin secretion and impaired glucose tolerance.25, 29 A possible mechanism for high blood pressure in obese individuals is hyperinsulinemia. Activation of the rennin-angiotensin-aldosterone system and reduction of renal sodium excretion by hyperinsulinemia are explanations for high blood pressure in obese individuals.25, 29 Hypertension is also a risk factor for cardiovascular diseases. 26 Moreover, majority of obese youth and adults experience psycho-social consequences of obesity. For example, low self-esteem and being targeted as a victim for bullying in schools are the social outcomes of obesity for youth.30 For 3 adults, obesity results in weight bias and discrimination in employment,31 psychological problems,32 not having a relationship with opposite sex in women and poor educational achievement in men.33 1.1.3 Assessments of Obesity Overweight and obesity should ideally be defined by the amount of body fat. However, the standard anthropometric measurements available to assess body fat are not ideal. Better measurement techniques are complex and costly, and impractical for epidemiological research and clinical assessment.34 In clinical settings, the skin fold measurement (the measurement of subcutaneous layer of fat) is accepted as a reasonable correlate of body fat.34-37 In combination with Body Mass Index-for-age to estimate adiposity in children, skinfold measurement can improve the estimation of body fatness except in overweight (≥95th percentile) children and adolescents.38,39 However, due to differences between observers, measurement errors are common, resulting in poor reliability and reproducibility.35-37 Thus, the common, inexpensive and practical method of obesity measurement, Body Mass Index (BMI), has been recommended, based on the high reliability of measurements of height and weight.34,35,40 BMI is calculated as the child’s weight in kilograms divided by his/her height in meters, squared. The limitation of this measurement is that it cannot accurately distinguish between 4 adiposity and muscularity.1,36 BMI for children also changes with age, so the BMI standard deviation scores and percentiles are more useful when tracking children and their progress. Similar to BMI, another practical method which has already been widely used for screening of overweight and obesity in preschool children is weight-for-height measurement. 40,41 In research settings, one of the commonly used methods include dual energy X-ray absorptiometry (DEXA) which can measure bone mass, lean body mass and fat mass separately and the accurate percentage of body fat can be calculated.34-36 Based on a similar theory, there is a method of under-water weighing (densitometry).35 Both methods require sophisticated apparatus and complex techniques.34 Besides DEXA, other accurate, rapid, non-invasive methods include the bioelectrical impedance analysis, computed tomography (CT/CAT scan) and magnetic resonance imaging (MRI/NMR). 3, 34 1.1.4 Definition of Obesity For adults, obesity is defined as a BMI ≥30kg/m² and overweight as a BMI between 25kg/m² to 29.99kg/m².1, 40 For children, although the BMI calculation is the same as for adults, obesity is determined based on BMI-for-age curves with percentile units, or weight-for-height curves. In addition, definition of obesity and overweight for children varies between countries.2 Two well known and commonly used definitions are from the 5 United States Centre for Disease Control (CDC) and the International Obesity Task Force (IOTF). Based on nationally representative data in the United States, the CDC defines a BMI above the 95th percentile for age as “overweight” and above the 85th percentile for age as “at-risk-for-overweight”.42 But these cut off points are mainly for the United States and are arbitrary. They are generally not considered appropriate for use with other populations/countries. The IOTF attempted to define obesity cut-off points which can be accepted internationally for the purpose of a unified international definition to facilitate epidemiological research and comparison across different populations. The IOTF defined percentile curves for overweight and obesity which intersect the adult cut-off points of a BMI of 25kg/m² and 30kg/m2 at age 18 years, respectively.43 The cut-off points proposed by the IOTF are age and sex specific, and are based on data from six countries: the United States, Great Britain, Hong Kong, the Netherlands, Brazil and Singapore.43 Although these cut-off points are recommended for international comparisons, the cut-offs are mainly representative of Western countries and less reflective of data from African and Asian countries.44 Moreover, data for Singapore children aged 2–6 years are not available for that dataset.43 Therefore, Singapore data was not included in the derivation of the IOTF cut-off points for children aged 2–6 years.43 Thus, the IOTF BMI cut-off points may not be applicable to preschool children in Singapore. 6 BMI and body fat percentage vary across different ethnic groups.45-48 Asians have a high body fat percentage with low BMI compared to Caucasians, due to differences in body composition.45,49,50 The WHO expert consultation on BMI in Asian population, held in Singapore, 2002, concluded that the current WHO BMI cut-off points may underestimate the prevalence of overweight and obesity for Asian populations based on adverse health outcomes for Asian populations, which occur at lower BMIs. Asian countries were encouraged to make decisions about the definitions of increased risk for their population and WHO BMI cut-off points were used for international comparisons.45 1.1.5 Ethnic Difference In the United States, Hispanic children are more obese than non-Hispanic black and non-Hispanic white children.26, 27, 51 Asians and Africans, except those from the Middle East and North Africa, have a lower prevalence of overweight and obesity than Western ethnic groups.52 The difference in prevalence of overweight and obesity among ethnicities may be due, in part, to differences in central fatness and muscularity, resulting in differences in body fat percentage and BMI.53 Generally, differences may be attributed to different patterns of food consumption, attitudes towards food or genetic differences. 7 1.2 Prevalence of obesity across countries 1.2.1 Methodology of literature review Using the PubMed database, I searched “prevalence AND (overweight OR obesity) AND preschool children” and total of 2,218 articles were found. I narrowed down the topic search to “prevalence of overweight and obesity study in preschool children” and found 865 articles. After that, I chose the titles related to the topics and found 63 articles. Next, I read through all the abstracts of these and retrieved 8 of the best articles. There were in total of 1,287 articles in the Scopus database and I followed the same method of literature review in PubMed database and finally, found 1 new good article from the Scopus database. 1.2.2 Asian countries A population-based study of the prevalence of obesity in preschool children was conducted in China in 2000. Liu et al. (2007)54 found a prevalence of 7.4% of overweight and obesity in a large population of 262,738 preschool children aged 3.5–6.4 years. The study areas were the northern rural, southern rural and southern urban areas. Children who were born between 1993 and 1996 to a mother residing in one of these areas for at least one year were included. The response rate was not mentioned. The study used international age- and genderspecific BMI cut-off points to compare with other countries and found that the 8 prevalence of obesity is similar to that of Great Britain or the United States in the 1980s or earlier. In 2000, according to data obtained from the National Nutritional Survey, de Onis and Blossner analysed 2,854,677 children from 94 developing countries, and found that the prevalence of obesity in 2 SDs from the NCHS/WHO international reference median value 3.3% ( all developing countries) - ObesityBMI >97th percentile 20.8% (boys) 19.1% (girls) OverweightCentiles corresponding to BMI 25kg/m2 De Onis M & Blossner M (2000) Ibrahim A.I. (2008) Developing countries (94 countries) Jordan Data obtained from National Nutritional Surveys from 94 countries < 5 year Children from randomly selected nurseries 3-6 year 2854,677 1695 Not mentioned Not mentioned Standard procedure of measurement Standard procedure by five well trained anthropometrists 2.9%(Asia) 3.9%(Africa) 4.4%(Latin America) 3.8% (boys) 7.2% (girls) OverweightBMI >95th to 97th percentile 15 Non-Asian countries Study Country Sampling frame Age N Response Rate Methodology Cut-off points Prevalence Obesity/ Overweight Using CDC measurement guidelines by trained interviewers Using standardized procedure by the public health nurses Obesity- BMI >95th percentile Overweight-BMI between 85th to 95th percentile Obesity-Centiles of BMI 30kg/m2 97.1% Examined by trained medical personal Not mentioned By classroom teachers trained by nutritionist from JUNJI program Obesity Centiles corresponding to BMI 30kg/m2 OverweightCentiles corresponding to BMI 25kg/m2 Obesity- BMI ≥95th percentile Odgen CL (2010) United States NHANES 20072008 2 -5 year 3281 82.1% Canning P.M (2004) Canada Children born in 1997 and subsequently enrolled in preschool health check program in 2002 Children attending school entry health examination 3–5 year 4161 73%-84% 5–6 year 126,083 Children registering in JUNJI program 2–5 year 25,013 (2004) Kalies H (2002) Germany Stanojevic S (2008) Chile Overweight/ At-risk-for overweight 10.4% 21.2% 25.6% - 2.8% 12.3% 16.35% (2004) 21.64% (2004) OverweightCentiles of BMI 25kg/m2 Overweight-BMI > 85th but < 95th percentile 16 Study Country Sampling frame Age N Response Rate Methodology Cut-off points Prevalence Obesity/ Overweight Kain J (2002) Maffeis C (2006) Chile Italy Children entering first grade Registering to kindergartens in several school districts 6 year 2–6 year 199,444 2150 Not mentioned 89.6% Using standardized procedure by trained teacher Standardized measurement by pediatricians Overweight /At-risk-for overweight W-H index ObesityW-H>+2s.d Overweight- W-H between >+1 and +2s.d CDC criteriaObesity- BMI ≥95th percentile Overweight-BMI between 85th to 95th percentile IOTF criteriaObesityCentiles of BMI 30kg/m2 Overweight- Centiles of BMI 25kg/m2 W-H index 17%(boys) 18.6%(girls) W-H index 20%(boys) 21.8%(girls) CDC criteria14.7% (boys) 15.8% (girls) CDC criteria19.2% (boys) 18.5% (girls) IOTF criteria 7.2%(boys) 7.5%(girls) IOTF criteria 18.8%(boys) 19.6%(girls) CDC criteriaOverweight-BMI >95th percentile At-risk-for overweightBMI>85th percentile IOTF criteria Obesity- BMI ≥97th percentile Overweight- BMI ≥ 90th percentile CDC criteria 16% CDC criteria Approximately 16% IOTF criteria Approximately 8% IOTF criteria Approximately 16% 17 1.3 Risk factors for Obesity Scientists have been trying to find out the risk factors for obesity in children to prevent the onset of obesity. Socioeconomic status (SES) and parental influences (such as parental educational status, cultural behaviors, and dietary habits) can be affected to the risk of overweight in their children. Furthermore, physical activity and sedentary behavior can also be associated with the prevalence of overweight and obesity. 1.3.1 Methodology of literature review Using the PubMed database, I searched “Risk factors of overweight and obesity” and total of 17,868 articles were found. Then, the topic was narrowed down more specifically as “Risk factors of overweight and obesity in preschool children” and found 1,066 articles. After that, I chose the titles related to the risk factors associated with overweight and obesity in preschool children and found 30 articles. The abstracts were all reviewed and 6 of the better articles were chosen. 1.3.2 Socioeconomic status (SES) The study by Lioret et al. (2007)64 from France (n=1,016) was the first nation-wide survey to cover a wide age range from 3–14 years old children and was representative of France. The study demonstrated an association between 18 SES and childhood overweight in a representative sample of French children aged 3–14 years. To obtain a representative sample, the study sample was selected through stratification and used the quota method (age, gender, household size, head of household socio-professional status) and the questionnaire was delivered to the participant’s house and explained by a trained and certified investigator. SES was determined by the occupation of the head of household in this study and divided into ‘High’ for executive, top-management or professional ones, ‘Middle’ for middle professions (employees, technicians or similar) and ‘Low’ for other jobs including unemployed people. The result of this study showed that children from low SES aged over 6–10 years and 11–14 years were three (p=0.01) and eight times (p=0.003) more likely to be overweight, including obesity (the BMI cutoff point which pass through the adult overweight cutoff points of 25 kg/m2 and 30 kg/m2 at 18 years), when compared to their counterparts in the high SES groups. A strong inverse relationship between SES and overweight was observed in children aged 6 years and above in France: compared to the low SES, the odds ratio for high SES was 0.3 (95%CI: 0.1,0.7) and that of middle SES was 0.5 (95%CI: 0.3,0.8). However, the association was not found in the 3-5 years old group in the study: compared to the low SES, the odds ratio for high SES was 0.4 (95%CI: 0.1,1.7) and that of middle SES was 1.3 (95%CI: 0.6,2.9). In addition, a German study (n=1,979) conducted by Lamerz et al. (2005)65 showed that children from low SES had three fold higher risks (95%CI: 1.92,5.63) to be obese (BMI ≥90th percentile) compared to those of high SES. The participating children were born in the specified period and the study was 19 conducted at the obligatory school entrance health exam and the response rate was high (97.9%). The questionnaire was presented in German, and SES was measured as cumulative index of different socioeconomic variables such as parental education according to German school system, living space in square meter per person living in the house and single parenthood. Jiang et al. (2006)66 from China also conducted a cross-sectional study to determine the risk factors for overweight in 2– to 6–year–old children (n=930) in Beijing, China. Their results showed that family income was not associated with childhood overweight (p=0.56). All children aged 2–6 years from five large kindergartens, randomly selected from two urban areas in Beijing, were invited for the study and 930 parents were participated (response rate of 89.1%). The questionnaire was subsequently modified to increase its reliability by doing some pretests before the final version of questionnaire was confirmed. 1.3.3 Parental Education In 2007, Manios et al.67 stated that the father’s and mother’s educational statuses were not associated with the risk of overweight and obesity in Greek preschool children aged 1–5 years old (n=2,374) (p-value for father’s education=0.901 and 0.628 for 1–3 years and 3–5 years old groups, respectively), (p-value for mother’s education= 0.949 and 0.062 for 1–3 years and 3–5 years old groups, respectively). The samples in this study were those preschool children who participated in the GENESIS (Growth, Exercise and Nutrition 20 Epidemiological Study In preSchoolers) study, in which they were randomly selected from 105 nurseries, and day-care centres in five counties. It was the first countrywide representative report with a response rate of 75%. Associations of obesity were assessed by a questionnaire in which the father’s or mother’s educational status was ranked by years of education into three groups: less than or equal to 9 years, 10–14 years and more than 14 years of education. The study had a good accuracy for anthropometrical measurements because all study sites used the same measuring equipment and same two well-trained team members. The Chinese study by Jiang et al. (2006)66 (n=930) also examined the association of the maternal education and SES with the risk of obesity in childhood. In this study, low maternal education which was defined as not completing high school and was significantly associated with childhood overweight (OR=2.22, 95%CI: 1.39,3.55), compared to mothers with higher education. Researchers Savva et al. (2005)68 in Cyprus also looked at risk factors for childhood overweight. They conducted a survey in 2005 with 1,412 children, selected by multistage sampling procedures, aged 2–6 years who attended public and private nursery schools in five districts. The response rate was 70.6% and the paternal and maternal educations were collected by questionnaire and divided into three groups: ‘College/University’, ‘High school graduate’, and ‘Some high school/elementary’. This study showed no association between obesity in preschool children with maternal education: compared to ‘Some high 21 school/elementary’ level, the odds ratio for ‘College/University’ level was 1.13 (95%CI: 0.52,2.46) and that for ‘High school graduate’ level was 1.31 (95%CI: 0.61,2.83). Paternal educational level was also not associated with obesity in preschool children: compared to ‘Some high school/elementary’ level, the odds ratio for ‘College/University’ level was 0.67 (95%CI: 0.34,1.27) and for ‘High school graduate’ level was 0.84 (95%CI: 0.46,1.54). In this study, the portable scale and stadiometer for anthropometrical measurements were calibrated daily and it was the first study in Cyprus to determine the prevalence of obesity in preschool children. Furthermore, Moschonis et al. (2008)69 conducted the first large scale epidemiological study in Greece, to evaluate the perinatal predictors of overweight in children aged 1–5 years old (n=2,374). The sample was randomly selected from both rural and urban areas, and the participation rate varied from 54% to 95% with the highest rate in rural area and the lowest in urban area. Participants were by analysed by dividing into age groups of 1–3 years old and 3– 5 years old according to current ages and also when the children were at the age of 6 months old and 12 months old. One of the predictors was the maternal educational level which was categorised into ‘Junior high school’, ‘High school’ and ‘College or University’. Only for the 3–5 years old group, the maternal educational level was found to predict childhood overweight (defined as weightfor-length ≥95th percentile at 6, 12 months and 1–2 years of age and BMI-for-age ≥85th percentile at 2–3 and 3–5 years of age): child who were born to mothers with a college or a university degree was 58% lower risks (95%CI: 0.34,0.98) to 22 be overweight compared to those who born to mothers with junior high school degrees. However, there were no associations of childhood overweight and the maternal educational level for other age groups: 6 months old group (OR=0.74,95%CI: 0.33,1.66), 12 months old group (OR=0.62, 95%CI: 0.251.54), 1–3 years old group (OR=1.19,95%CI: 0.39,3.60) when compared to maternal education of ‘Junior high school’ versus ‘College or University’. Moreover, comparison to ‘Junior high school’ versus ‘High school’ of maternal education also showed no associations with childhood overweight for all age groups: 6 months old group (OR=1.02, 95%CI: 0.38,2.74), 12 months old group (OR=0.94, 95%CI: 0.31,2.84), 1–3 years old group (OR=2.32,95%CI: 0.63,8.33) and 3-5 years old group (OR=0.89,95%CI: 0.45,1.72). 1.3.4 Parental Overweight/Obesity A cross-sectional study from China by Jiang et al. (2006)66 (n=950) examine the association between child (2– to 6–year–old) overweight and parental overweight/maternal overweight. The China study included all children aged 2–6 years from five large kindergartens, randomly selected from two urban areas in Beijing, and the response rate of 89.1%. The information of height and weight of participating parents were obtained by asking questionnaire and BMI ≥25 kg/m2 was defined as parental/maternal overweight. Their results showed that parental overweight and maternal overweight were significantly associated with childhood 23 overweight [(OR=2.43,95%CI: 1.78,5.69) and (OR=1.20,95%CI: 1.07,1.33), respectively]. The first countrywide representative report from Greece conducted on preschool children aged 1–5 years old (n=2,374) determining the association of parental weight with overweight for children (response rate=75%).67 The parental weight status was obtained by asking questionnaire and the study categorized into two groups of parental obesity: ‘None’ and ‘One/Both’. The results showed that overweight or at risk for overweight in 3 to 5 years old children was associated with having one or two obese parents (p=30kg/m2’ had 3.24 times greater odds (95%CI: 1.59,6.61) and those with mother whose BMI level ‘>30kg/m2’ had 3.91 times greater odds (95%CI: 1.78,8.59) for being obesity, compared to those with father or mother whose BMI level ‘18.5–24.9kg/m2’. 24 1.3.5 Physical Activity Lioret et al. (2007)64 examined the relationship between leisure time physical activity (LTPA) and overweight in children aged 3–14 years (n=1,016) in their study. They considered LTPA as the usual amount of time spent (not intensity) taking part in various sports outside school in an ordinary week and accessed it by three categories: ‘no LTPA’, ‘intermediate’ and ‘high’, using two thresholds of zero and the 80th percentile of the time distribution. The questionnaire was derived from the French translation70 of the Modifiable Activity Questionnaire which was primarily designed for adolescents and adapted for children.71 More than half of the preschool children (3– to 5–year–old–group) had no LTPA, and the result showed that preschool children who performed intermediate LTPA were significantly less likely to be overweight (OR=0.2,95%CI: 0.1,0.7) than those who had no LTPA. Furthermore, the Chinese study66 (n=930) included physical activity as one of the potential risk factors to determine the association with the risk of obesity. The physical activity for children was assessed by the time spent on physical activity, excluding physical activity in kindergarten, and the results showed that physical activity and the childhood overweight were not associated (data was not mentioned). A study from Japan, based on the Toyama cohort study (n=8,170), by Sugimori et al. (2004)72 also showed a significant association between overweight and physical activity (p=[...]... searched Risk factors of overweight and obesity and total of 17 , 868 articles were found Then, the topic was narrowed down more specifically as Risk factors of overweight and obesity in preschool children and found 1, 066 articles After that, I chose the titles related to the risk factors associated with overweight and obesity in preschool children and found 30 articles The abstracts were all reviewed and. .. response rates of their studies The use of different cut-off points of obesity and overweight limits comparisons between studies 31 In Singapore, no population-based studies have been conducted on young preschool -aged children to our knowledge Our study aims to determine the prevalence of obesity in Singapore Chinese preschoolers aged 6 72 months 32 Table 2 Obesity and associated risk factors across countries... associations were found in overweight children of other age groups when compared to maternal smoking (both active and passive smoking) and non-smoking during pregnancy: OR=0.77,95%CI: 0.39 ,1. 50 in children aged less than 6 months, OR =1. 38,95%CI: 0 .67 ,2.87 in children aged 6 12 months, OR =1. 53,95%CI: 0.74,3 .18 in children aged 1 3 years Cigarette smoking during pregnancy was analysed by dividing into ‘Nonsmoker’,... lower than that in the United States and Australia .60 There were two studies in Chile: a study in 2008 of children aged 2 to 5 years (n=25, 013 ) by Stanojevic et al., with a prevalence of 16 . 4 % 61 and one in 2002 by Kain et al., with a prevalence of 14 .7% in boys and 15 .8% in girls in a group of 6 years old children (n =19 9,444) .62 These two studies did not mention the response rates In the 2008 study,... 0.28,0. 86 in children aged less than 6 months, OR=0.54,95%CI: 0.28,0.98 in children aged 6 12 months) when compared to their counterparts in the exclusive formula groups However, in children aged 1 3 years and 3–5 years, exclusive breastfeeding for the first 6 months of life was not found to be protective (OR=0.89,95%CI: 0. 51, 1. 56 in children aged 1 3 years, OR=0.94,95%CI: 0 .65 ,1. 35 in children aged 3–5... children aged 6 12 months, OR=0. 86, 95%CI: 0.37,2. 01 in children aged 1 3 years and OR =1. 31, 95%CI: 0.75,2.29 in children aged 3–5 years) 1. 3 .10 Limitations of the studies regarding risk factors The study from France64 did not mention the response rate of the study, and the accuracy of the BMI values may be affected by the self reported weight and height for both children and parents The Chinese study 66 study... smoker’ and ‘Passive and active 29 smoker’ Mothers were interviewed and asked to choose according to these categories and 7.8% of them were both active and passive smokers during their pregnancy In this Greek study ,69 maternal alcohol consumption during pregnancy and overweight in childhood was not associated (OR =1. 31, 95%CI: 0 .68 ,2.55 in children aged less than 6 months, OR =1. 37,95%CI: 0 . 61 ,3 .11 in children. .. for overweight in preschoolers (1 5 years old) Breastfeeding patterns from birth to 6 months were also assessed by questionnaire, dividing into three categories: ‘Exclusive formula’, ‘Mixed’ and ‘Exclusive breastfeeding’ 28 They found that exclusive breastfeeding for the first 6 months and 6 12 months of life was found to be protective factors for the risk of overweight at 6 and 12 months of age (OR=0.49,95%CI:... by dividing into age groups of 1 3 years old and 3– 5 years old according to current ages and also when the children were at the age of 6 months old and 12 months old One of the predictors was the maternal educational level which was categorised into ‘Junior high school , ‘High school and ‘College or University’ Only for the 3–5 years old group, the maternal educational level was found to predict... al., in 2002, reported that the prevalence of obesity between 5 6 years old children was 2.8% in Bavaria, the largest and the second most populated state of Germany .60 This study was based on a huge number of children (1 26, 083) from the school entry health examination and had a very high response rate of 97 .1% In comparison with countries with the same definition of obesity, the prevalence of obesity in ... young preschool -aged children to our knowledge Our study aims to determine the prevalence of obesity in Singapore Chinese preschoolers aged 6 72 months 32 Table Obesity and associated risk factors. .. children aged 6 12 months, OR=0. 86, 95%CI: 0.37,2. 01 in children aged 1 3 years and OR =1. 31, 95%CI: 0.75,2.29 in children aged 3–5 years) 1. 3 .10 Limitations of the studies regarding risk factors The... of the prevalence of obesity in preschool children was conducted in China in 2000 Liu et al (2007)54 found a prevalence of 7.4% of overweight and obesity in a large population of 262 ,738 preschool