Abusive alcohol consumption among adolescents: a predictive model for maximizing early detection and responses.

OBJECTIVE: To present a predictive model of alcohol abuse among adolescents based on prevalence projections in various population subgroups. STUDY DESIGN: Cross-sectional study. METHODS: The sample consisted of 785 adolescents enrolled in the second year of high school in Rio de Janeiro, Brazil. Alcohol consumption was assessed using the Alcohol Use Disorder Identification Test. Socio-economic, demographic, family, individuals, and school-related variables were examined as potential predictors. The logit model was used to estimate the prevalence projections. Model fitting was examined in relation to the observed data set, and in a subset, that was generated from 200 subsamples of individuals via a bootstrap process using general fit estimators, discrimination, and calibration measures. RESULTS: About 25.5% of the adolescents were classified as positive for alcohol abuse. Being male, being 17-19 years old, not living with mothers, presenting symptoms suggestive of binge eating, having used a strategy of weight reduction in the last 3 months, and, especially, being a victim of family violence were important predictors of abusive consumption of alcohol. While the model's prevalence projection in the absence of these features was 8%, it reaches 68% in the presence of all predictors. CONCLUSIONS: Knowledge of predictive characteristics of alcohol abuse is essential for screening, early detection of positive cases, and establishing interventions to reduce consumption among adolescents.

Risk behaviors for eating disorders in Brazilian dancers.

This study investigated the frequency of risk behaviors for eating disorders and their association with anthropometric, demographic, and socioeconomic variables in Brazilian professional dancers. Portuguese-language versions of the Eating Attitudes Test and of the Bulimic Investigatory Test, Edinburgh (BITE) were applied to 39 female and 22 male dancers considered to be some of the best classical ballet performers in Brazil. Prevalence ratios (PR) and 95% confidence intervals (CI) were estimated. Risk behaviors for eating disorders were observed in 31% of the dancers. Those who had a percentage of body fat above (PR=4.04; 95% CI=1.42-11.47) or below (PR=3.57; 95% CI=1.04-12.24) what is considered normal for the profession, and those who lived alone (PR=3.13; 95% CI=1.16-8.48) presented higher risk for eating disorders. In conclusion, the frequency of risk behaviors for eating disorders among the Brazilian dancers was high, which seems to be associated with the physical requirements of the profession. Those who are outside the BF% expected for dancers and those who live alone are the groups most vulnerable to developing eating disorders, and thus are the ones which are most in need of receiving special attention in regard to the intervention measures.

[Factors associated with obesity among adolescents]. / Fatores associados à obesidade em adolescentes.

INTRODUCTION: Obesity during adolescence is considered a strong predictor of adult obesity. The present study assessed the overweight/obesity prevalence and associated factors in middle class adolescents of a school in the city of Niteroi, Rio de Janeiro, Brazil, and evaluated the correlation between body mass index with anthropometric measures of fatness. METHOD: The analysis covered 391 students aged from 15 to 17 years. Adolescents had their weight, height, skinfold thickness and upper arm circumference measured at school. A food frequency questionnaire (list of 79 items) and a questionnaire including food habits, parents anthropometric characteristics, physical activity and other factors associated with obesity were filled out by the adolescents at school. RESULTS: The proportion of overweight individuals among boys (Body Mass Index (BMI) greater than the 90th percentile of the Brazilian population) was 23.9%, whereas the prevalence among girls was 7.2%. The fact of being on a slimming diet was a relevant factor for the prediction of BMI and was 7 times more frequent among girls than among boys. Among boys, being on a diet, absence of breakfast, and family body appearance were positively associated with BMI. Among girls these variables were also significantly associated, whereas age at menarche was negatively associated with BMI. Hours of watching TV/video/video-game was associated with BMI only among boys. The correlation coefficient between BMI and measures of fatness varied from 0.7 to 0.9 for boys, and from 0.8 to 0.90 for girls. CONCLUSIONS: BMI appears to be a good indicator of obesity among adolescents and showed that girls demonstrated an exaggerated preoccupation with body image and stereotyped slim body patterns.

[Evaluation of body composition by means of anthropometric measures in obese and non obese adolescents from two socioeconomic levels]. / Avaliação da composição corporal através de medidas antropométricas, de adolescentes obesas e eutróficas de dois níveis sócio-econômicos.

Anthropometric measures of 120 female adolescents were analyzed, 60 of them from a low socio-economic level (LSEL),and 60 from a high socio-economic level (HSEL), with 30 obese and 30 non-obese in each group, in an attempt to verify differences between the socio-economic levels in relation to the body-composition and the distribution of fat throughout the body. The weight,height, upper arm circumference and 4 skin folds (triceps, biceps,subscapular and suprailiac) were measured, and the arm muscle area, arm fat area and percentage of body fat were estimated. Those who were obese from LSEL presented an average height lower (p<0.05) than the obese from HSEL, and a greater proportion of this group presented a height deficit for their age. The arm muscle area was greater (p<0.05) in the obese from HSEL, but the percentage of body fat was similar in the two groups as well as the measures of the isolated skin folds. The increase in fat in the obese from LSEL, when compared with the non-obese, was 2.8 times greater than the muscle. In the HSEL, this increase was 1.3 times greater. It was concluded that the obese from both socio-economic levels presented different types of obesity in relation to body composition,but were similar in relation to body fat distribution.

[Distribution of body mass indices of a Brazilian population under 25 years of age]. / Distribuição dos valores do índice de massa corporal da população brasileira até 25 anos.

This paper presents the percentage distribution of the body mass index of the Brazilian population from birth to age 25, based on a national survey conducted in 1989. Survey data show that body mass index decreases from birth until around 6 years of age, reaching a plateau at 8 years and progressively increasing until the age of 19 or 20 years for females and 20 or 21 for males. The survey also revealed that after the age of 12 females present a greater body mass index than males, as well as a larger range of percentile values (from 3 to 97). A comparison with data from other countries showed that the body mass index profile in Brazil is similar to that observed in France, Great Britain, and the United States. Before the age of 6, Brazilian youngsters have a mean body mass index that resembles that of North American children, and a lower one thereafter. A comparison between the median body mass index of Brazilian and British youngsters revealed consistently lower values among Brazilian females. When compared to that of France, Brazil's male population has a systematically lower body mass index after the age of 8. It is suggested that the data presented in our study be used only for comparing groups of individuals and studies, and not for screening or clinical monitoring, due to the great variability in growth patterns during adolescence.

A comparison of distribution curves of body mass index from Brazil and the United States for assessing overweight and obesity in Brazilian adolescents.

OBJECTIVE: To assess the validity of recommendations for use of the 85th and 95th percentiles of body mass index (BMI) of the population in the United States of America as a screening tool to assess overweight/obesity in adolescents. METHODS: We investigated the relation between BMI and percent body fat in 1,540 adolescents (717 males and 823 females) aged 10 to 17.9 years old from a private high school in Niterói, a city in the state of Rio de Janeiro, Brazil. We used bioelectric impedance, with the appropriate equations for adolescents, to estimate percent body fat, which served as the gold standard (30% for girls and 25% for boys) to calculate the sensitivity and specificity of the 85th and 95th percentiles of the United States and Brazilian distribution curves of BMI. RESULTS: Sensitivity and specificity were high (above 80%) for the Niterói boys, except for the 85th percentile of the Brazilian curve (specificity = 61.8%) and for the 95th percentile of the United States curve (sensitivity = 55.4%). For the Niterói girls, the 85th- and 95th-percentile BMI cutoff points, from both the United States and Brazilian curves, showed low sensitivity, and that sensitivity decreased with age. Specificity was high for the girls, and much higher than it was for the boys. CONCLUSIONS: These data suggest that using BMI to screen for overweight/obesity in adolescents can generate a high percentage of false-positives for Niterói boys and an even higher percentage of false-negatives for Niterói girls. A more universal approach to using anthropometric measures to screen for overweight/obesity should be developed, preferably linked to stages of maturation.