Association between socioeconomic vulnerability and height with obesity in low-income Chilean children in the transition from preschool to first grade.

This study determined the percentage of obesity among lower-income Chilean children 4-6 years of age, by socioeconomic vulnerability (family score assessing the children's risk of becoming poor) and height. The sample included 17,080 children with anthropometry at 4, 5, and 6 years of age, and three categories of socioeconomic vulnerability. Body mass index Z-score (BMI Z), % obesity, height/age Z-score (HAZ) by socioeconomic vulnerability/sex, the effect of socioeconomic vulnerability on BMI Z and HAZ by age/sex, and BMI Z and % obesity at 4-6 years, according to initial height, were determined. Between 4-6 years, % obesity is very high, especially among the less-vulnerable and taller children. Preventive measures should prioritize this group.

Epidemiología del sobrepeso y obesidad infanto-juvenil en las comunas de Concepción, Coronel y Hualpén, VIII Región de Chile / Frequency of obesity and overweight among school age children living in southern Chile

Background: The frequency of obesity is increasing steadily in Chile. Aim: To assess the prevalence of obesity and overweight in children and teenagers living in three southern Chilean cities. Material and Methods: The database of an evaluation performed in 2006 in schools, was used to obtain weight and height of 32514 subjects aged 12 ± 4 years (48 percent males). Criteria proposed by the International Obesity Task Force (IOTF) and the Centers for Disease Control (CDC) were used to define obesity and overweight. Results: According to CDC criteria the prevalence of overweight and obesity was 11.2 percent and 6.5 percent, respectively. According to IOTF criteria, the fgures were 13.2 and 4 percent, respectively. The higher frequency of overweight and obesity was observed among children aged less than eight years. Conclusions: There is a high frequency of obesity and overweight in the studied sample.

Evolución del estado nutricional de niños chilenos desde la etapa preescolar a la escolar: Resultados antropométricos según procedencia de las mediciones / Evolution of the nutritional status of Chilean children from preschool to school age: Anthropometric results according to the source of the data

Como los resultados del estado nutricional que entregan instituciones chilenas que recolectan datos antropométricos de su población bajo control, muestran diferentes magnitudes en el incremento del porcentaje de obesidad entre preescolares de 4 años y escolares de 1er grado, quisimos verificar la real magnitud de este aumento. Este estudio se basó en una investigación longitudinal que comenzó el 2006 con 1100 niños de 3 años, evaluados por el INTA a los 4, 5 y 6 años. Se determinó el estado nutricional a esas edades según Z IMC y referencias OMS 2006/2007. La información recogida sirvió además, para determinar la concordancia entre los datos antropométricos recogidos por profesores de escuelas públicas en escolares de 1er grado el 2009 (base JUNAEB) y los mismos niños evaluados paralelamente por el INTA (base INTA). La muestra incluyó a 474 niños de 6 años. No se observaron diferencias entre los promedios de Z IMC y Z talla/edad. El grado de concordancia entre los Z IMC fue bueno (rho= 0,73), sin embargo hubo diferencias en la clasificación nutricional, ya que el porcentaje de bajo peso fue significativamente mayor en la base JUNAEB (9,5% vs 3,6% ), mientras que el porcentaje de obesidad fue menor en la base INTA, 17,5% vs 19,2% (diferencia no significativo). A los 4 y 5 años los porcentajes de obesidad de estos niños fueron 13,3% y 15,7% respectivamente (datos INTA). Por la trayectoria observada, es más probable que el alza en el porcentaje de obesidad entre los 4 y 6 años fue de 4 puntos porcentuales y no de 6, tal como indican los datos INTA.

Because the results of the nutritional status released by Chilean institutions which collect anthropometric data on their population under control, show different increments in the prevalence of obesity between preschoolers and children in 1st grade, we decided to verify the real magnitude of this increase. This study is based on a longitudinal investigation which began in 2006 and included 1100, three-year old children, which we evaluated when they were 4, 5 and 6 y. The nutritional status was determined according to BMI Z and WHO References 2006 / 2007. The information was also used to determine the concordance between the anthropometric data collected on first graders by teachers from public schools in 2009 (JUNAEB data set) and the same children assessed in parallel by INTA (INTA data set). The sample included 474, six-year olds. No differences were found between the average BMI Z and HAZ of the two data sets, and the degree of concordance between the BMI Z´s was good (rho = 0.73), however there were differences in the nutritional status, since the prevalence of low weight was significantly greater when assessed with JUNAEB´s data (9.5% vs 3.6% ), while that for obesity was lower with INTA´s data, 17.5% vs. 19.2% (not significantly different). At 4 and 5 y, obesity prevalence of the children was 13.3% and 15.7% respectively (INTA´s data). Considering the observed nutritional trajectory, it is likely that the rise in obesity between 4 and 6 y of age, was 4 percentage points and not 6, as was determined with INTA´s data.

[Frequency of obesity and overweight among school age children living in southern Chile]. / Epidemiología del sobrepeso y obesidad infanto-juvenil en las comunas de Concepción, Coronel y Hualpén, VIII Región de Chile.

BACKGROUND: The frequency of obesity is increasing steadily in Chile. AIM: To assess the prevalence of obesity and overweight in children and teenagers living in three southern Chilean cities. MATERIAL AND METHODS: The database of an evaluation performed in 2006 in schools, was used to obtain weight and height of 32514 subjects aged 12 ± 4 years (48% males). Criteria proposed by the International Obesity Task Force (IOTF) and the Centers for Disease Control (CDC) were used to define obesity and overweight. RESULTS: According to CDC criteria the prevalence of overweight and obesity was 11.2% and 6.5%, respectively. According to IOTF criteria, the fgures were 13.2 and 4%, respectively. The higher frequency of overweight and obesity was observed among children aged less than eight years. CONCLUSIONS: There is a high frequency of obesity and overweight in the studied sample.

[Evolution of the nutritional status of Chilean children from preschool to school age: anthropometric results according to the source of the data]. / Evolución del estado nutricional de ninos chilenos desde la etapa preescolar a la escolar: resultados antropométricos según procedencia de las mediciones.

Because the results of the nutritional status released by Chilean institutions which collect anthropometric data on their population under control, show different increments in the prevalence of obesity between preschoolers and children in 1st grade, we decided to verify the real magnitude of this increase. This study is based on a longitudinal investigation which began in 2006 and included 1100, three-year old children, which we evaluated when they were 4, 5 and 6 y. The nutritional status was determined according to BMI Z and WHO References 2006/2007. The information was also used to determine the concordance between the anthropometric data collected on first graders by teachers from public schools in 2009 (JUNAEB data set) and the same children assessed in parallel by INTA (INTA data set). The sample included 474, six-year olds. No differences were found between the average BMI Z and HAZ of the two data sets, and the degree of concordance between the BMI Z's was good (rho = 0.73), however there were differences in the nutritional status, since the prevalence of low weight was significantly greater when assessed with JUNAEB's data (9.5% vs. 3.6% ), while that for obesity was lower with INTA's data, 17.5% vs. 19.2% (not significantly different). At 4 and 5 y, obesity prevalence of the children was 13.3% and 15.7% respectively (INTA's data). Considering the observed nutritional trajectory, it is likely that the rise in obesity between 4 and 6 y of age, was 4 percentage points and not 6, as was determined with INTA's data.

[Nutritional surveillance in Chilean schoolchildren: validity of the information]. / Vigilancia nutricional en escolares chilenos: Validez de la información.

BACKGROUND: Anthropometry is used to survey health and nutritional situation of the population. Therefore the quality of the information that is being used must be evaluated. AIM: To estimate the agreement in weight, height and nutritional status in schoolchildren, comparing measurements made by teachers in schools and a standardized and supervised team of professionals. MATERIAL AND METHODS: Cross sectional study including 927 schoolchildren in 31 schools from 7 counties of Santiago. Schools were randomly chosen and the universe of children attending to first grade was measured. Weight, height and nutritional status collected by teachers and researches, were compared. RESULTS: Total agreement for nutritional status reached 0.67, random-weighted Kappa was 0.40 and weighted Kappa, 0.42. Teachers tended to over diagnose under-nutrition and under diagnose overweight and obesity measuring 270 grams less than the qualified team (p <0.001) and 1.7 cm more in height (p <0.001), what is reflected in a difference of less than one point in body mass index (p <0.001). Discrepancies in height and body mass index were higher in extreme values. CONCLUSIONS: There is a low agreement between the measurements taken by the research team and teachers. Even though there are discrepancies between measurements, high levels of overweight and low prevalences of stunting and underweight are kept, reflecting problems with exactitude, but not bias. Corrective actions to improve the quality of information, which should include training programs for teachers, instrument maintenance, supervision and verification system for data entry, are needed.

Vigilancia nutricional en escolares chilenos: validez de la información / Nutritional surveillance in Chilean schoolchildren: validity ofthe information

Background: Anthropometry is used to survey health and nutritional situation of the population. Therefore the quality of the information that is being used must be evaluated. Aim: To estímate the agreement in weight, height and nutritional status in schoolchildren, comparing measurements made by teachers in schools and a standardized and supervised team of professionals. Material and methods: Cross sectional study including 927 schoolchildren in 31 schools from 7 counties of Santiago. Schools were randomly chosen and the universe of children attending to first grade was measured. Weight, height and nutritional status collected by teachers and researches, were compared. Results: Total agreement for nutritional status reached 0.67, random-weighted Kappa was 0.40 and weighted Kappa, 0.42. Teachers tended to over diagnose under-nutrition and under diagnose overweight and obesíty measuríng 270 grams less than the qualified team (p <0.001) and 1.7 cm more in height (p <0.001), what is reflected in a difference of less than one point in body mass index (p <0.001). Discrepancies in height and body mass índex were higher in extreme valúes. Conclusions: There is a low agreement between the measurements taken by the research team and teachers. Even though there are discrepancies between measurements, high levéis of overweight and low prevalences of stunting and underweight are kept, reílecting problems with exactitude, but not bias. Corrective actions to improve the quality of information, which should include training programs for teachers, instrument maintenance, supervisión and verification system for data entry, are needed.

Association of perinatal factors and obesity in 6- to 8-year-old Chilean children.

BACKGROUND: It has been reported in Chile that obesity figures in children of 6- to 8-years-old are associated with height for age. We studied the possible influence of perinatal variables on obesity at 6- to 8-years-old controlling for height for age. METHODS: All children with 6-8 years of age attending first grade in public primary schools of Chile in year 2005 were included. An historical cohort design was used and perinatal information collected at birth was obtained from the National Registry. Obesity was defined as BMI >or=95th percentile of the CDC reference. Comparisons of obesity prevalence in contingency tables used the chi-squared test. Logistic regression was used to calculate ORs for obesity risk in univariate and multivariate categorical models. RESULTS: Out of 167 494 initial subjects, 153 536 children entered the study. Obesity prevalence was higher in stunted and in tall for age children (20.1 and 26.0%, respectively) compared with those with normal height for age (17.3%) (P < 0.0001). Adjusted odds ratio for perinatal information showed that infants born male, premature and short in length at birth were more prone to obesity than their counterparts. However, birth weight (BW) had a stronger positive influence on obesity risk. CONCLUSIONS: Taller and stunted children had higher obesity risk than normal height for age children. This association did not change when controlling for the influence of perinatal data; post-natal influences may be playing an independent role. Although BW was linearly associated with obesity, short and premature babies also had a higher risk of obesity.

[Evolution of the nutritional status of six years old Chilean children (1987-2003)]. / Evolución del estado del estado nutricional de escolares chilenos de 6 años (1987-2003).

BACKGROUND: As a consequence of the epidemiological transition in Chile, the nutritional status of the population has changed notoriously. AIM: To study the changes in the nutritional status of six years-old Chilean children from 1987 to 2003. MATERIAL AND METHODS: The computer data base of a government institution in charge of the School Lunch Program (JUNAEB) was used. It contains data on weight, height, sex and date of birth of six years old children, in the years 1987, 1990, 1993, 1996, 2000, 2001, 2002 and 2003. RESULTS: The data of approximately 80,000 children was analyzed. Both weight and height increased over the study years. There was a significant reduction in the number of children with weight deficit but also an increase in the proportion of children with obesity. Stunting was also reduced. The proportion of children with HAZ over 2 SD increased from 0.76 in 1987 to 2.2% in 2003. The prevalence of obesity has not increased since the year 2000. CONCLUSION: The stabilization in the prevalence of obesity is a positive finding, considering its adverse consequences for health.

Trends in height and BMI of 6-year-old children during the nutrition transition in Chile.

OBJECTIVE: We analyzed trends in height and BMI and their interaction in 6-year-old Chilean children over the last 15 years. RESEARCH METHODS AND PROCEDURES: We calculated height for age z-score (HAZ), BMI z-score, prevalence of obesity, underweight, and stunting from cross-sectional national school-based annual population surveys in 1987, 1990, 1993, 1996, 2000, and 2002. Using mixed model analysis, we determined the risk of obesity according to height over time as odds ratios (ORs) and 95% confidence interval and the potential influence of height and year of study on BMI z-score. RESULTS: Over the study period, height increased by 2.8 cm in boys and 2.6 cm in girls, whereas stunting declined from 5% to 2% in both. Tallness increased by approximately 2%, BMI z-score increased from +0.3 to +0.65 in boys and to +0.62 in girls, and HAZ increased from -0.47 in boys and -0.45 in girls to 0 in 2002. Underweight declined from 4% to 3%, whereas obesity rose from 5% to approximately 14%. The probability of obesity among tall children was significantly greater than that for normal height children (OR, 2.3 to 3.5). The lowest obesity risk was observed between -2 and -1 HAZ. The OR for obesity in the stunted relative to normal height children was variable, ranging from 1.23 to 0.65, whereas it was significant and consistently positive (1.1 to 1.7) for boys and girls when it was compared with the lowest obesity risk according to height. DISCUSSION: Tallness is significantly associated with increased obesity risk in children, while stunting is also associated, but to a lesser degree.