Changes in BMI and the prevalence of overweight and obesity in children and adolescents in Cracow, Poland, 1971-2000.

The aim of this study is to examine changes in prevalence of overweight and obesity, using International Obesity Task Force criteria, in three cohorts of children and youth living in Cracow, Poland, in 1971, 1983 and 2000. Rates of overweight and obesity doubled among boys and girls, from 7.5% and 6.5% in 1971, to 15.2% and 11.8% in the year 2000. The greatest increases in prevalence occurred in the youngest age groups (7-12 years for boys and 7-10 years for girls), increases being less extensive among adolescents, and lowest of all in the oldest age groups (16-18 years in boys and 14-18 years in girls). The absence of a positive secular trend in BMI among adolescent females relative to males may be due to sociocultural pressures associated with transition to a free market economy in Poland. The extent to which girls attempt to achieve the ideal body, as portrayed by media and society more generally, increases across adolescence.     

Changes in BMI and the prevalence of overweight and obesity in children and adolescents in Cracow, Poland, 1971–2000

The aim of this study is to examine changes in prevalence of overweight and obesity, using International Obesity Task Force criteria, in three cohorts of children and youth living in Cracow, Poland, in 1971, 1983 and 2000. Rates of overweight and obesity doubled among boys and girls, from 7.5% and 6.5% in 1971, to 15.2% and 11.8% in the year 2000. The greatest increases in prevalence occurred in the youngest age groups (7–12 years for boys and 7–10 years for girls), increases being less extensive among adolescents, and lowest of all in the oldest age groups (16–18 years in boys and 14–18 years in girls). The absence of a positive secular trend in BMI among adolescent females relative to males may be due to sociocultural pressures associated with transition to a free market economy in Poland. The extent to which girls attempt to achieve the ideal body, as portrayed by media and society more generally, increases across adolescence.     

Overweight in Childhood,Adolescence and Adulthood and Cardiovascular Risk in Later Life: Pooled Analysis of Three British Birth Cohorts

Background

Overweight and obesity in adulthood are established risk factors for adverse cardiovascular outcomes, but the contribution of overweight in childhood to later cardiovascular risk is less clear. Evidence for a direct effect of childhood overweight would highlight early life as an important target for cardiovascular disease prevention. The aim of this study was to assess whether overweight and obesity in childhood and adolescence contribute to excess cardiovascular risk in adults.

Methods and findings

Data from three British birth cohorts, born in 1946, 1958 and 1970, were pooled for analysis (n = 11,447). Individuals were categorised, based on body mass index (BMI), as being of normal weight or overweight/obese in childhood, adolescence and adulthood. Eight patterns of overweight were defined according to weight status at these three stages. Logistic regression models were fitted to assess the associations of patterns of overweight with self-reported type 2 diabetes, hypertension, and coronary heart disease (CHD) in adulthood (34–53 years). Compared to cohort members who were never overweight, those who were obese in adulthood had increased risk of all outcomes. For type 2 diabetes, the odds ratio was higher for obese adults who were also overweight or obese in childhood and adolescence (OR 12.6; 95% CI 6.6 to 24.0) than for those who were obese in adulthood only (OR 5.5; 95% CI 3.4 to 8.8). There was no such effect of child or adolescent overweight on hypertension. For CHD, there was weak evidence of increased risk among those with overweight in childhood. The main limitations of this study concern the use of self-reported outcomes and the generalisability of findings to contemporary child populations.

Conclusions

Type 2 diabetes and to a lesser extent CHD risk may be affected by overweight at all stages of life, while hypertension risk is associated more strongly with weight status in adulthood.     

Prevalence of overweight and obesity among the affluent adolescent school children of Amritsar, Punjab

In the present study, an attempt has been made to assess the prevalence of overweight and obesity in adolescent children (between 10-15 years of age) of the affluent families of Amritsar district of Punjab, a state in rapid economic and epidemiological transition. A total of 640 children (323 boys and 317girls) were measured for height and weight. Overweight and obesity were assessed using age and sex-specific body mass index (BMI) cut-off points. 9.91% boys and 11.99% girls were overweight, and 4.95% boys and 6.31% girls were obese. The prevalence of overweight and obesity among the affluent children in Amritsar was as high or higher as in some industrialized countries.     

Contributions of Incidence and Persistence to the Prevalence of Childhood Obesity during the Emerging Epidemic in Denmark

Background

Prevalence of obesity is the result of preceding incidence of newly developed obesity and persistence of obesity. We investigated whether increasing incidence and/or persistence during childhood drove the prevalence of childhood obesity during the emerging epidemic.

Methods

Height and weight were measured at ages 7 and 13 years in 192,992 Danish school children born 1930–1969. Trends in the incidence (proportion obese at 13 years among those not obese at 7 years) and persistence (proportion obese at 13 years among those obese at 7 years) across birth cohort periods (1930–41 with low stable prevalence of obesity, 1942–51 with increasing prevalence, 1952–69 with the higher, but stable prevalence) were investigated. Logistic regression was used to examine the associations between BMI at 7 years as a continuous trait, allowing interactions with the birth cohorts, and occurrence of obesity at 13 years.

Results

The prevalence of obesity was similar at 7 and 13 years and increased across birth cohorts in boys from around 0.1% to 0.5% and in girls from around 0.3% to 0.7%. The incidence of obesity between ages 7 and 13 years increased from 0.15% to 0.35% in boys and from 0.20% to 0.44% in girls. The persistence increased from 28.6% to 41.4% in boys and from 16.4% to 31.0% in girls. Despite a decrease over time, the remission of obesity occurred in >60% of obese children in the last birth cohort. However, the odds ratios of obesity at age 13 years in relation to the full range of BMI at 7 years remained unchanged across the birth cohort periods.

Conclusions/Significance

The development of the obesity epidemic in children was due to an increase in both incidence and persistence of obesity. Contrary to prevailing expectations, a large, although declining, proportion of children obese at an early age underwent remission during childhood.     

Biocultural aspects of gender differences in body composition and obesity during childhood and adolescence

Gender differences in body composition, the prevalence in overweight and obesity as well as in physical activity patterns were tested among 3003 children and adolescents aging between 6 and 18 years (x = 12.1 +/- 3.6) in Vienna and rural parts of Eastern Austria. As to be expected, the absolute and relative amount of body fat was significantly higher among girls of nearly all age groups, while boys exhibited a significantly higher amount of lean or fat free body mass. The prevalence of overweight and obesity was markedly higher among prepubertal girls, however significantly lower among younger and older adolescent girls aging 11 years and older in comparison to their male counterparts. This was however only true of adolescents originating from Austria. Considering adolescents with a background of migration originating from Turkey or the Near East, a significantly higher amount of overweight and/or obesity was found among girls. Therefore, biocultural factors have to be considered to explain gender differences in obesity during childhood and adolescence.     

Longitudinal study of obesity in the National Survey of Health and Development.

In a nationally representative cohort of 5362 children born in one week in March 1946 weights and heights were recorded at 6, 7, 11, 14, 20, and 26 years. Overweight was defined as a weight that exceeded the standard weight for height, age, and sex by more than 20% (relative weight greater than 120%). The prevalence of overweight was 1.7% and 2.9% in boys and girls respectively at 6 years; 2.0% and 3.8% at 7 years; 6.4% and 9.6% at 11 years; 6.5% and 9.6% at 14 years; 5.4% and 6.5% at 20 years; and 12.3% and 11.2% at 26 years. The risk of being overweight in adulthood was related to the degree of overweight in childhood and was about four in 10 for overweight 7-year-olds. Analysis of the data in the reverse direction showed that 7% and 13% respectively of 26-year-old overweight men and women had been overweight at the age of 7. These results suggest that there is no optimal age during childhood for the prediction of overweight in adult life and that excessive weight gain may begin at any time. Overweight children are more likely to remain overweight than their contemporaries of normal weight are to become overweight.     

Obesity among male adolescent migrants in Vienna, Austria

Childhood overweight and obesity--especially among migrant children--are health problems in several European countries. The prevalence rates of overweight and obesity among 936 migrant boys of low socio-economic status from Turkey and former Yugoslavia were compared with those of Austrian boys in Vienna. In the longitudinal study, children were measured at the ages of 6, 10 and 15 years. Weight status was estimated by means of the body mass index and percentile curves were used for weight status classification. The prevalence of overweight and obesity was high among migrant boys as well as Austrian boys at all age groups. Ten-year-old boys from Yugoslavia exhibited the highest percentage of overweight (nearly 38%). The lowest percentage of overweight was among 6-year-old Austrian boys (17.2%). Being overweight or obese at the age of 6 years increased the risk of being overweight at 10 and 15 years significantly (p<0.001). This was true of all groups independent of migrant status. The impact of migrant status on weight status at the ages of 10 and 15 was not significant. Therefore, although migrant boys from former Yugoslavia exhibited the highest rates of overweight and obesity, migrant status is not associated significantly with an increased prevalence of obesity in this sample characterized by a generally low socio-economic status. Prevention should start as early as possible for all children, since overweight tends to persist from childhood into adolescence independent of migrant status.     

Prevalence of obesity in elementary schoolchildren living in Northeast Attica, Greece

Objective: To assess the prevalence of obesity and obesity trend in schoolchildren living in Northeast Attica, Greece. Research Methods and Procedures: Mean (standard deviation) and median weight and BMI were calculated in 4131 (2054 boys and 2077 girls) 6‐ to 11‐year‐old Greek schoolchildren living in Northeast Attica between November 2003 and April 2004. Two hundred thirty‐six (95 boys, 141 girls) immigrant children also participated in the study. The secular trend for obesity was determined comparing our data with those of a similar study performed in 1994. Results: Of boys, 27.8% were overweight, and 12.3% were obese. For girls, the corresponding values were 26.5% for overweight and 9.9% for obesity. There was an increase in the prevalence of overweight and obesity in the last 10 years in both sexes. For boys, overweight increased by 4.2% and obesity by 2.9%, whereas, for girls, overweight increased by 3.8% and obesity by 1.6%. Overweight and obesity were less prevalent in the immigrant children compared with their Greek peers. For immigrant boys, overweight was 15.9% and obesity was 7.9%, and for immigrant girls, overweight was 15.2% and obesity was 8.7%. Discussion: Greek schoolchildren living in Northeast Attica present a high prevalence of overweight and obesity and a positive secular change in the prevalence of obesity.     

Racial Differences in the Tracking of Childhood BMI to Adulthood

Objective: The possibility that there are racial differences in the patterns of BMI (kilograms per meter squared) change throughout life has not been examined. For example, the high prevalence of obesity among black women could result from a higher prevalence of obesity among black girls or because normal‐weight black girls experience larger BMI increases in adolescence or adulthood than do their white counterparts. Therefore, we examined the tracking of childhood BMI into adulthood in a biracial (36% black) sample. Research Methods and Procedures: Five‐ to 14‐year‐old children (2392) were followed for (mean) 17 years. Childhood overweight was defined as BMI ≥ 95th percentile, and adult obesity was defined as BMI ≥ 30 kg/m². Results: The tracking of childhood BMI differed between whites and blacks. Among overweight children, 65% of white girls vs. 84% of black girls became obese adults, and predictive values among boys were 71% (whites) vs. 82% (blacks). These racial differences reflected contrasting patterns in the rate of BMI change. Although the initial BMI of black children was not higher than that of white children, BMI increases with age were larger among black girls and overweight black boys than among their white counterparts. In contrast, relatively thin (BMI < 50th percentile) white boys were more likely to become overweight adults than were their black counterparts. Discussion: These findings emphasize the black/white differences in BMI changes with age. Because of the adult health consequences of childhood‐onset obesity, early prevention should be given additional emphasis.     

Trends in the prevalence of overweight and obesity among young Australians, 1985, 1997, and 2004

Objective: To determine secular trends in overweight/obesity among 7‐ to 15‐year‐olds for the periods 1985, 1997, and 2004. Research Method and Procedures: Data from representative surveys conducted in New South Wales, Australia, in 1985, 1997, and 2004 were analyzed. Height and weight were measured, and BMI categories were created using International Obesity Task Force definitions. Students were grouped as Grades 2 + 4 + 6 and 8 + 10. Results: The prevalences of overweight/obesity for 1985, 1997, and 2004 were 10.9%, 20.6%, and 25.7% among the younger boys and 10.6%, 19.5%, and 26.1% among the older boys. The average annual rate of increase for 1985 to 1997 was 0.81% and for 1997 to 2004 was 0.73% among the younger boys and was 0.74% and 0.94% for the two periods among the older boys. The prevalences of overweight/obesity in 1985, 1997, and 2004 were 14.0%, 22.0%, and 24.8% among the younger girls and 8.3%, 17.9%, and 19.8% among the older girls, respectively. The average annual rates of increase for the two periods were 0.8% and 0.4% among the younger girls and 0.80% and 0.27% among the older girls. Change in the prevalence of overweight/obesity and socioeconomic status were not associated. Discussion: Over the period 1985 to 1997, the prevalence of overweight and obesity increased significantly among the younger and older boys and the younger girls. The prevalence of overweight, but not obesity, increased among the older girls over this period. Over the period 1997 to 2004, the prevalence of overweight/obesity combined increased significantly among boys of both age groups but not among girls.     

The extent of overweight index in children and adolescents from Cracow,Poland (1971–2000)

Obesity indices describe the percentage of overweight and obese children in a given population but they do not show the extent to which the norms have been exceeded. The aim of this work was to determine the extent of overweight index (EOW), suggested by Jolliffe, 2004a, Jolliffe, 2004b, by examining children and adolescents from Cracow in order to obtain information on overweight and obesity prevalence and on the amounts by which the BMI age- and sex-specific norms are exceeded, emphasising usefulness of EOW in population studies.The study material comprises three randomly selected groups, representative for Cracow: (1) measured in 1971 which includes 4090 individuals of both sexes and aged 7–19 years, (2) measured in 1983 with 6542 individuals aged 3–19 years and (3) measured in 2000 with 4524 boys and girls aged 3–19 years. The EOW index of overweight is a mean relative deviation from BMI threshold, assuming that for values lower than the threshold ones, the deviation amounts to zero.The EOW index values in boys increased from 0.9 in 1971 up to 2.2 in 2000 i.e. by 144%, indicating an increase of both prevalence of overweight and obesity and an increase of the amount by which the limits of overweight are exceeded. In girls the index also increased, though less dramatically, from 0.7 in 1971 to 1.5 in 2000 i.e. by 114%.An analysis of the results showed that the increasing prevalence of overweight and obesity in children and adolescents is accompanied by an increase of the amount by which the BMI threshold values are exceeded.     

Onset of overweight in Nuuk, Greenland: a retrospective cohort study of children from 1973 to 1992

The purpose of the study was to examine the age at onset of overweight and obesity of 2-15-year-old children in Nuuk, Greenland, born between 1973 and 1992. The study was a retrospective cohort study. The data were retrieved from the children's individual health files containing information on height and weight, and the database contained a total of 12,002 measurements of BMI in 3,094 children (1,522 boys and 1,572 girls). The main outcome measure was age at onset of overweight-the age at which BMI was above an internationally recommended cutoff point for overweight. The study showed that an increasing proportion of children reached the overweight state and did so at an earlier age for later cohorts. This was seen for both boys and girls. Overweight was less prevalent among boys in all cohorts. For the 1973-1992 cohorts of children from Nuuk, Greenland, the age at onset of overweight was significantly decreased.     

Obesity and Overweight Prevalence in Polish 7‐ to 9‐Year‐Old Children

Objective: Secular trend in childhood obesity is a well‐known phenomenon, and it is important to monitor it in cross‐sectional studies. The study aim was to estimate prevalence of obesity and overweight in Polish 7‐ to 9‐year‐old children and to compare the results with a French study based on the same protocol. Research Methods and Procedures: The study was conducted in 2001 according to the protocol of the European Childhood Obesity Group. Height and weight were measured, and BMI was calculated to define nutritional status in a randomly selected group of 2916 (1445 girls and 1471 boys) primary school children. Obesity and overweight were estimated according to International Obesity Task Force references with curve for obesity and overweight passing through 30 and 25 kg/m² at age 18, respectively. Results: Overweight (including obesity) was found in 15.4% of Polish children (in 15.8% of girls and 15.0% of boys) and obesity in 3.6% (3.7% of girls and 3.6% of boys) compared with 18.1% of overweight and 3.8% of obese children in French study. There was no significant difference in nutrition status between Polish and French children except for higher frequency of overweight in French 9‐year‐old boys. The same trend of decreasing overweight through age classes was observed in both populations. Discussion: The prevalence of obesity and overweight (including obesity) in prepubertal children estimated in two European countries according to the same protocol and using the same references showed little differences between the two populations despite higher prevalence of obesity in Polish than French adults.     

Obesity and Malnutrition in a Shantytown Population in the City of São Paulo,Brazil

To investigate the prevalence of obesity and malnutrition in the poor Brazilian population we conducted a survey on the socioeconomic and nutritional status of 535 families (comprising 2 411 individuals) living in shanty towns in the city of São Paulo. There was a 30% prevalence of malnutrition in the children, with chronic malnutrition as the most predominant problem. The prevalence of obesity was 6.4% in boys and 8.7% in girls. Overweight and obesity associated with stunting was found in 5.8% of boys and 6.8% girls. Adolescents showed a higher prevalence of malnutrition when weight-for-age distribution was used (boys 46.4%, girls 40.2%), but a right deviation in the distribution was observed with an increase in obesity and a decrease of malnutrition was observed (obesity was 21% in girls and 8.8% in boys; malnutrition was 15.5% in boys and 12.6% in girls) when the weight-for-height adjustment was made. Stunting was the most predominant type of malnutrition in both sexes. Obesity associated with stunting was more common than obesity without stunting, both in younger children and adolescents. Adults had a higher prevalence of obesity than malnutrition according to both the Metropolitan Life Insurance tables (1.7% of undernutrition, 16.7% of overweight, and 14.1% of obesity) and Body Mass Index (8.5% of undernutrition, 21.9% of overweight, and 14.6% of obesity). There was an increase in the percentage of obese children when at least one adult in the family was obese and an increased percentage of malnourished children when undernourished adults were present in the family. Obesity among the adults of the family decreased the occurrence of malnutrition among the children. In 9% of families there was a coexistence of obesity in the adults and malnutrition in the children. These results demonstrate a coexistence of malnutrition and obesity in poor urban Brazilian communities.     

Geographic and Demographic Variation in the Prevalence of Overweight Canadian Children

Objective : To examine the geographic and demographic variation in the prevalence of overweight Canadian children. Research Methods and Procedures : Using BMI data from the 1981 Canada Fitness Survey and the 1996 National Longitudinal Survey of Children and Youth, this study assessed: 1) the prevalence of overweight and obesity among Canadian boys and girls ages 7 to 13 years; 2) secular trends in the prevalence of overweight from 1981 to 1996, by province and adjusted for age and sex; and 3) provincial variation in the prevalence of overweight, before and after adjusting for socioeconomic and demographic characteristics. Results : The prevalence of boys and girls classified as overweight in 1996 was 33% and 26%, respectively. The corresponding figures for obesity were 10% for boys and 9% for girls. Provincial variation was observed with a trend of increasing risk of being overweight from west to east. Socioeconomic status was inversely related to the prevalence of overweight regardless of geographic region. The risk of being overweight was more related to geography (province) than demographic variables (income and family background); however, the effect of secular trends (1981 to 1996) exceeded the effect of geographic or demographic variables. Discussion : The prevalence of childhood overweight and obesity is increasing in all areas of Canada and can be explained only partially by geographic or demographic characteristics.     

Differences in physical activity between non-overweight, overweight and obese children

The purpose of the study was to find out differences in moderate to vigorous physical activity among non-overweight, overweight and obese children, and between boys and girls. The sample included 364 children (179 boys and 185 girls), aged 6.4 years (+/- 0.3 SD). Physical activity was assessed by 7-day questionnaire. Age adapted BMI was used as overweight and obesity indicator. The children were divided into non-overweight, overweight and obese groups. It was found out, that there are significant differences in non-overweight, overweight and obese children (p < 0.05). Boys were significantly (p < 0.05) less moderate to vigorous physical active than girls, especially in indoor activities. There were also significant differences (p < 0.05) in moderate to vigorous physical activity among non-overweight and obese boys and among overweight and obese boys in weekends and total weekly activity. In girls there are significant differences (p < 0.05) in non-overweight, overweight and groups in weekends and total weekly activity. It is possible to conclude, that obese boys and overweight and obese girls, are prone to less physical activity.     

Body mass index, prevalence of overweight and obesity in Lithuanian children and adolescents, 1985-2002

The study provides the body mass index (BMI), the prevalence of overweight (OW) and obesity (OB) in Lithuanian children and adolescents, 1985-2002. In the 2000-2002 more than 9000 schoolchildren of 7-18 years old were investigated in the 5 biggest towns and surrounding settlements of Lithuania. These data were compared with the 1985 data. The prevalence of OW and OB was estimated using the International Obesity Task Force (IOTF) cut-off points. The prevalence of OW in Lithuanian children and adolescents was higher among younger schoolchildren in comparison with older adolescents. OW was lower among the older girls in comparison with the older boys: 4.60%-11.50%/4.80%0-13.62% in the 7-13 years girls/boys, versus 1.50%-6.60%/3.90%-9.50% in the 14-18 years old girls/boys. The prevalence of OW among younger Lithuanian adolescents did not change significantly in the last 15 years, but it slightly decreased in older boys and demonstrably diminished in older adolescent girls. In generally, the prevalence of OW among Lithuanian adolescents is low in comparison with the prevalence of OW in children from the other countries.     

Prevalence and determinants of obesity in children in public schools of Sintra, Portugal

Objective: To assess the prevalence of and the factors related to overweight and obesity in a sample of children from the region of Sintra, Portugal. Methods and Procedures: Cross‐sectional study, stratified for freguesia with random selection of schools. Height, weight, triceps skinfold, upper arm and waist circumferences were measured, and overweight/obesity defined according to international criteria. Breast‐feeding, number of daily meals and parents' height and weight data were also collected. Results: One thousand two hundred and twenty‐five children aged 6–10 years were assessed. Overall prevalence of overweight and obesity was 35.6% (23% overweight and 12.6% obesity). Overweight or obese children had higher triceps skinfold, upper arm circumference, arm muscle area, and waist circumference than their normal weight counterparts (P < 0.001). On multivariate analysis, relatively to a child without obese progenitors, a child with one obese progenitor had an obesity risk multiplied by 2.78 (95% confidence interval (CI): 1.76–4.38), while a child with two obese progenitors had a risk multiplied by 6.47 (95% CI: 5.59–16.19). Conversely, being picky was significantly related with a smaller risk of obesity: for boys, odds ratio (OR) = 0.15 (95% CI: 0.04–0.63); for girls, OR = 0.19 (95% CI: 0.06–0.64). Finally, no relationships were found between obesity, birth weight, birth height or breast‐feeding. Discussion: Prevalence of overweight and obesity are elevated among children of the Sintra region in Portugal compared to most other regions of Europe. The relationship with the parents' nutritional state stresses the need to target families for preventing obesity.