Influence of different body mass index cut-off values in assessing the nutritional status of adolescents in a household survey

Prevalence of overweight and obesity among Brazilian adolescents over time: a systematic review and meta-analysis

OBJECTIVE

To estimate the burden of excess weight in Brazilian adolescents.

DESIGN

Systematic review with meta-analysis.

SETTING

We searched the literature in four databases (MEDLINE/PubMed, EMBASE, SciELO and LILACS). Studies were included if they had cross-sectional or cohort design and enrolled Brazilian adolescents. Studies based on self-reported measures were excluded. Random effect models were used to calculate prevalence estimates and their 95 % CI.

PARTICIPANTS

Brazilian adolescents (10 to 19 years old).

RESULTS

One hundred and fifty-one studies were included. Trend analyses showed a significant increase in the prevalence of excess weight in the last decades: 8·2 % (95 % CI 7·7, 8·7) until year 2000, 18·9 (95 % CI 14·7, 23·2) from 2000 to 2009, and 25·1 % (95 % CI 23·4, 26·8) in 2010 and after. A similar temporal pattern was observed in the prevalence of overweight and obesity separately. In sensitivity analyses, lower prevalence of excess weight was found in older adolescents and those defined using International Obesity Task Force cut-off points. The Southeast and South regions had the highest prevalence of excess weight, overweight and obesity. No significant difference in prevalence by sex was found, except for studies before the year 2000.

CONCLUSIONS

The prevalence of overweight and obesity in Brazilian adolescents is high and continues to rise. Public policies on an individual level and targeting modifications in the obesogenic environment are necessary.

Estado nutricional dos alunos da Rede Nacional de Ensino de Educação Infantil e Fundamental do Serviço Social do Comércio (Sesc), Brasil, 2012

Resumo O objetivo deste estudo foi identificar e descrever o crescimento e o perfil nutricional antropométrico das crianças matriculadas na Rede Nacional de Ensino do Sesc. Trata-se de um estudo transversal realizado em 20.113 escolares (9.992 meninas) em 83 escolas com idades de 3 a 17 anos. O estado nutricional foi determinado pelo índice de massa corporal e estatura para a idade. Os resultados indicaram baixa prevalência de baixa estatura: 1,6% para meninas e 1,3% para meninos. No entanto, EMC (excesso de massa corporal) foi encontrado em 29,7% das crianças, sendo 27,6% em meninas e 32,3% em meninos. Nas crianças até 5 anos, EMC foi igual a 12,3% (10,9% em meninas e 13,25% em meninos). Na faixa etária de 5 a 10 anos, os resultados foram de 35,3% para as meninas e 40,1% para os meninos, sendo de 37,8% em todo o grupo. A prevalência de EMC para crianças acima de 10 anos foi de 37,4% (32,5% em meninas e 43,0% em meninos). As prevalências de EMC encontradas em todas as faixas etárias foram expressivas e o problema se agrava nas crianças maiores e nos meninos. Estes resultados corroboram a situação relatada nos estudos nacionais de alta prevalência de EMC e reforçam a necessidade de acompanhamento do estado nutricional devido aos agravos associados ao EMC infantil e suas consequências na vida adulta.

Prevalence and factors associated with stunting and thinness among adolescent students in Northern Ethiopia: a comparison to World Health Organization standards

BACKGROUND

Adolescence is last chance for curbing the consequences of malnutrition and breaking the intergenerational cycle of malnutrition and poor health. This study aimed to assess the prevalence and the factors associated with stunting and thinness among in-school adolescents in northern Ethiopia using the 2006 World Health Organization (WHO) standards.

METHODS

In-school adolescents (n = 348, 10-19 years old) were randomly selected to participate in this cross-sectional study. Anthropometric measurements were carried out to determine the proportion of adolescents who were stunted (height-for-age < -2 Standard Deviation (SD)) and thin (body-mass-index-for-age < -2 SD). T-test was employed to evaluate mean weight and height differences between groups. Pearson chi-square, chi-square trend and Fisher's exact tests were used to explore the crude association of categorical outcome variables and associated factors. Crude and adjusted associations between the outcome variables (stunting and thinness) and independent variables (socio-demographic, eating behavior and sanitation) were also determined using logistic regression. Stata version 11.1 was used to analyze the data.

RESULTS

The height of the adolescents was 147.6 ± 11.2 cm (mean ± SD) and weight was37.2 ± 9.5 kg. The mean Z-scores of height-for-age and body-mass-index (BMI)-for-age of adolescents were -1.49 and -1.29, respectively. The prevalence of stunting and thinness among adolescents was 28.5 % (boys = 37.7 %; girls = 21.2 %; P = 0.001) and 26.1 % (boys = 32.4; girls = 21.6 %; p = 0.017), respectively. Adolescents in 13-15 year old age group (Adjusted Odds ratio (AOR) = 2.23; 95 % CI: 1.22, 4.08), boys (AOR = 2.53; 95 % CI: 1.52, 4.21) and rural residents (AOR = 2.15; 95 % CI: 1.20, 3.86) had significantly higher odds of being stunted compared to their counterparts. Furthermore, boys had higher (AOR = 1.97; 95 % CI: 1.19, 3.25) odds of being thin compared to girls. Compared to those 10 to 12 years of age, adolescents in 16 to 19 years of age were 53 % (AOR = 0.47; 95 % CI: 0.23, 0.95) less likely to be thin.

CONCLUSIONS

Undernutrition is widely prevalent among adolescents in northern Ethiopia. Sex, age and area of residence significantly associated with adolescent undernutrition. The study underlines the need for nutrition interventions targeting rural and boy adolescents.

Low body weight/thinness, overweight and obesity of children and adolescents from a Brazilian region of low economic status

OBJECTIVE

To assess the prevalence of low body weight/thinness, overweight and obesity in a representative sample of children and adolescents from a Brazilian region with low economic development.

METHODS

A total of 982 girls and 986 boys, aged seven to 17 years old and assisted by Segundo Tempo Program, from Montes Claros, Minas Gerais, Brazil, were included in the study. Low body weight/thinness, overweight and obesity were defined based on body mass cut-off indexes recommended by the International Obesity Task Force. The prevalence of the nutritional status according to sex and age was compared by chi-square test.

RESULTS

In girls, the frequency of low body weight/thinness, overweight and obesity was 4.1, 18.4 and 3.8%, respectively; in boys, these percentages were 6.3, 13.2 and 2.9%, respectively. The low body weight/thinness for girls raised from 2.7% (7-10 years old) to 5.5% (15-17 years old); the body weight excess (overweight and obesity) decreased from 30.1 to 16.2% for the same age groups. In boys, the corresponding trends were from 3.2 to 9.4% for low body weight/thinness, and from 23.4 to 9.2%, for body weight excess.

CONCLUSIONS

The data indicate that, even in a region with low economic status, the body weight excess was the main problem associated with nutritional health. The high overweight and obesity prevalence rates indicate the need of public policies for promoting healthy feeding behaviors and physical activity.

Childhood and adolescent overweight and obesity in Latin America: a systematic review

The number of children and adolescents who are overweight or obese worldwide is alarming. We did a systematic review to estimate the prevalence of overweight and obesity in children aged 0-19 years in Latin America. We searched specialised databases and seven books for relevant studies that were done in Spanish-speaking and Portuguese-speaking Latin American and Caribbean countries and published in peer-reviewed journals between January 2008, and April 2013. Indicators used were BMI (kg/m(2)) in all age groups and weight-for-height in children younger than 5 years. We identified 692 publications and included 42. Estimated prevalence of overweight in children younger than 5 years in Latin America was 7·1% with the weight-for-height WHO 2006 classification method. National combined prevalences of overweight and obesity with the WHO 2007 classification method ranged from 18·9% to 36·9% in school-age children (5-11 years) and from 16·6% to 35·8% in adolescents (12-19 years). We estimated that 3·8 million children younger than 5 years, 22·2-25·9 million school-age children, and 16·5-21·1 million adolescents were overweight or obese. Overall, between 42·5 and 51·8 million children aged 0-19 years were affected-ie, about 20-25% of the population. Although undernutrition and obesity coexist in the region, policies in most countries favour prevention of undernutrition, and only a few countries have implemented national policies to prevent obesity. In view of the number of children who are overweight or obese, the associated detrimental effects on health, and the cost to health-care systems, implementation of programmes to monitor and prevent unhealthy weight gain in children and adolescents are urgently needed throughout Latin America.

The relationship between obesity, insulin and arsenic methylation capability in Taiwan adolescents

PURPOSE

This study evaluated the arsenic methylation profile of adolescents and explored the influence of body mass index (BMI) on the arsenic methylation profile of adolescents in an area of Taiwan with no-obvious arsenic exposure.

METHODS

This study evaluated 202 normal weight students and 101 obese students from eight elementary schools, recruited from September 2009 to December 2009. Concentrations of urinary arsenic species, including inorganic arsenic, monomethylarsonic acid (MMA(5+)) and dimethylarsinic acid (DMA(5+)) were determined by a high-performance liquid chromatography-linked hydride generator and atomic absorption spectrometry.

RESULTS

Urinary total arsenic was significantly decreased with increasing BMI, indicating that obese children may retain higher levels of arsenic in the body, as compared to normal weight children. Participants with obesity accompanied by high insulin levels had higher inorganic arsenic, significantly higher MMA percentage and significantly lower DMA percentage than those with obesity and low insulin levels. It seems children with obesity and high insulin levels had lower arsenic methylation capacity than those with obesity and low insulin.

CONCLUSIONS

This is the first study to demonstrate that total urinary arsenic is negatively associated with the BMI in adolescents in Taiwan, adjusted for age and sex. Obese adolescents with high insulin levels had significantly higher MMA% and significantly lower DMA% than obese adolescents with low insulin.

Prevalence of thinness in children and adolescents in the Seychelles: comparison of two international growth references

BACKGROUND

Thinness in children and adolescents is largely under studied, a contrast with abundant literature on under-nutrition in infants and on overweight in children and adolescents. The aim of this study is to compare the prevalence of thinness using two recently developed growth references, among children and adolescents living in the Seychelles, an economically rapidly developing country in the African region.

METHODS

Weight and height were measured every year in all children of 4 grades (age range: 5 to 16 years) of all schools in the Seychelles as part of a routine school-based surveillance program. In this study we used data collected in 16,672 boys and 16,668 girls examined from 1998 to 2004. Thinness was estimated according to two growth references: i) an international survey (IS), defining three grades of thinness corresponding to a BMI of 18.5, 17.0 and 16.0 kg/m2 at age 18 and ii) the WHO reference, defined here as three categories of thinness (-1, -2 and -3 SD of BMI for age) with the second and third named "thinness" and "severe thinness", respectively.

RESULTS

The prevalence of thinness was 21.4%, 6.4% and 2.0% based on the three IS cut-offs and 27.7%, 6.7% and 1.2% based on the WHO cut-offs. The prevalence of thinness categories tended to decrease according to age for both sexes for the IS reference and among girls for the WHO reference.

CONCLUSION

The prevalence of the first category of thinness was larger with the WHO cut-offs than with the IS cut-offs while the prevalence of thinness of "grade 2" and thinness of "grade 3" (IS cut-offs) was similar to the prevalence of "thinness" and "severe thinness" (WHO cut-offs), respectively.

Association between body mass index and arsenic methylation efficiency in adult women from southwest U.S. and northwest Mexico

Human arsenic methylation efficiency has been consistently associated with arsenic-induced disease risk. Interindividual variation in arsenic methylation profiles is commonly observed in exposed populations, and great effort has been put into the study of potential determinants of this variability. Among the factors that have been evaluated, body mass index (BMI) has not been consistently associated with arsenic methylation efficiency; however, an underrepresentation of the upper BMI distribution was commonly observed in these studies. This study investigated potential factors contributing to variations in the metabolism of arsenic, with specific interest in the effect of BMI where more than half of the population was overweight or obese. We studied 624 adult women exposed to arsenic in drinking water from three independent populations. Multivariate regression models showed that higher BMI, arsenic (+3 oxidation state) methyltransferase (AS3MT) genetic variant 7388, and higher total urinary arsenic were significantly associated with low percentage of urinary arsenic excreted as monomethylarsonic acid (%uMMA) or high ratio between urinary dimethylarsinic acid and uMMA (uDMA/uMMA), while AS3MT genetic variant M287T was associated with high %uMMA and low uDMA/uMMA. The association between BMI and arsenic methylation efficiency was also evident in each of the three populations when studied separately. This strong association observed between high BMI and low %uMMA and high uDMA/uMMA underscores the importance of BMI as a potential arsenic-associated disease risk factor, and should be carefully considered in future studies associating human arsenic metabolism and toxicity.

Stunting associated with poor socioeconomic and maternal nutrition status and respiratory morbidity in Colombian schoolchildren

BACKGROUND

There are few recent reports on the prevalence and risk factors of stunting and thinness among schoolchildren in Latin America.

OBJECTIVE

To determine the prevalence and sociodemographic correlates of stunting and thinness among school-age children in Bogotá, Colombia, and to examine whether these nutritional indices are associated with the risk of respiratory and diarrheal morbidity symptoms, visits to the doctor, and school absenteeism during the school year in a prospective study.

METHODS

We obtained information on anthropometric and maternal sociodemographic characteristics of 3100 children 5 to 12 years of age who attended public primary schools in 2006 and who came from low- and middle-income households. Data on the incidence of common gastrointestinal and respiratory symptoms were collected prospectively on morbidity diaries throughout the year.

RESULTS

The prevalence rates of stunting and thinness were 9.9% and 8.7%, respectively. There were inverse, statistically significant trends in the prevalence of stunting by categories of child's birth and current weight; maternal education level, height, and body mass index (BMI); and household socioeconomic stratum. A strong positive association was found with maternal parity (p for trend < .0001). Thinness was positively associated with the child's and the mother's age and inversely associated with birthweight and maternal BMI. Stunting was associated with a 44% increase in the incidence of cough with fever during the school year (p = .04).

CONCLUSIONS

Child stunting in Bogotá is associated with poor socioeconomic and maternal nutritional status and predicts symptoms of respiratory infection.

Associação entre o estado nutricional antropométrico e a situação sócio-econômica de adolescentes em Niterói, Rio de Janeiro, Brasil

Investigou-se a relação entre o estado nutricional e a situação sócio-econômica familiar de adolescentes moradores de Niterói, Rio de Janeiro, Brasil. Os dados de 523 adolescentes, pertencentes a uma amostra probabilística de 1.734 domicílios, foram coletados entre janeiro e dezembro de 2003 e representam os 71.922 jovens residentes em Niterói. As análises incluíram a estimação de intervalos de confiança de razões de prevalência e testes de distribuições proporcionais e de independência entre classes de estado nutricional e classes de renda familiar per capita e as faixas de número de moradores do domicílio. Foi encontrada uma associação positiva significativa entre baixo peso/magreza e o número de moradores do domicílio (sexo masculino: p < 0,05; sexo feminino: p < 0,001). O número de moradores do domicílio encontra-se diretamente associado ao baixo peso/magreza em adolescentes. Foi evidenciada uma tendência positiva de aumento na proporção de adolescentes com sobrepeso/obesidade segundo os quintos de renda familiar per capita.