Waist-to-height ratio percentiles and cutoffs for obesity: a cross-sectional study in brazilian adolescents.

This study aimed to describe the distribution of waist-to-height ratio (WHtR) percentiles and cutoffs for obesity in Brazilian adolescents. A cross-sectional study including adolescents aged 10 to 15 years was conducted in the city of São Paulo, Brazil; anthropometric measurements (weight, height, and waist-circumference) were taken, and WHtRs were calculated and then divided into percentiles derived by using Least Median of Squares (LMS) regression. The receiver operating characteristic (ROC) curve was used in determining cutoffs for obesity (BMI ≥ 97th percentile) and Mann-Whitney and Kruskal-Wallis tests were used for comparing variables. The study included 8,019 adolescents from 43 schools, of whom 54.5% were female, and 74.8% attended public schools. Boys had higher mean WHtR than girls (0.45 ± 0.06 vs 0.44 ± 0.05; p=0.002) and higher WHtR at the 95th percentile (0.56 vs 0.54; p<0.05). The WHtR cutoffs according to the WHO criteria ranged from 0.467 to 0.506 and 0.463 to 0.496 among girls and boys respectively, with high sensitivity (82.8-95%) and specificity (84-95.5%). The WHtR was significantly associated with body adiposity measured by BMI. Its age-specific percentiles and cutoffs may be used as additional surrogate markers of central obesity and its co-morbidities.

Relação de amizade de adolescentes obesos e eutróficos / Friendship among obese and eutrofic adolescents / Relación de amistad de adolescentes obesos y eutróficos

Na adolescência, ampliam-se os horizontes sociais. Muitos obesos têm uma autoimagem crítica e tornam-se mais isolados. Objetivo: verificar o grau de intimidade nos relacionamentos entre pares de adolescentes obesos, comparando-os a eutróficos. Método: participaram 160 adolescentes, sendo 80 obesos (IMC > 95, grupo estudo). Instrumento: foi usado o friendship questionarie, que caracteriza o interesse, intimidade e integração com amigos. Procedimentos: o grupo estudo respondeu ao instrumento em um ambulatório para adolescentes e o grupo controle em uma escola. Resultados: não houve diferença estatística significante (p=0,412) entre o escore médio do GE (80,08) e GC (81,99). Entre os obesos, não houve diferença estatística (p=0,220) entre o sexo masculino ( X ou = 82,83) e o feminino ( X ou = 78,51); entre os eutróficos, as moças ( X ou = 84,88) tiveram uma média significativamente maior (p=0,016) que os rapazes ( X ou = 76,90). Conclusão: não houve diferenças em relação ao grau de intimidade com os pares entre adolescentes obesos e eutróficos. Ambos os grupos estudados procuram investir em uma amizade mais íntima e forte. A obesidade parece afetar menos os relacionamentos sociais dos adolescentes masculinos.

Social horizons expand during adolescence. Many obese individuals have a poor self-image and become more isolated. This paper aims to determine the degree of intimacy in peer relationships among obese adolescents in comparison to eutrofic ones. Out of the 160 adolescents who took part in the research, 80 were obese (BMI > 95, Study Group) and 80 presented a normal range. The instrument used was a Friendship Questionnaire, characterizing interest, intimacy and integration with friends. The procedure consisted of the study group answering the questionnaire at a clinic for adolescents, and the control group doing the same at a school. Results pointed out that there was no significant statistic difference (p=0.412) between the mean score of the study group (80.08) and that of the control group (81.99). Among the obese individuals, there was no statistic difference (p=0.220) between males ( X or = 82.83) and females ( X or = 78.51); among the eutrofic ones, the females ( X or = 84.88) had a significantly higher mean score (p=0.016) than the males ( X or = 76.90). In conclusion, there was no difference as to the degree of intimacy with peers between obese and eutrofic adolescents. Both groups were seeking to invest in a more intimate, deeper friendship. Obesity appears to have less effect on the social relationships of male adolescents.

En la adolescencia se amplian los horizontes sociales. Muchos obesos poseen una auto-imagem crítica y se vuelven más aislados. Objetivo: verificar el grado de intimidad en las relaciones entre pares de adolescentes obesos y eutroficos. Método: Participaron 80 adolescentes obesos (IMC > 95) e 80 eutróficos. Instrumento: Fue utilizado el Friendship Questionarie que caracteriza el interes, intimidad e integración con amigos. Procedimientos: El grupo estudio respondió al instrumento en un ambulatório para adolescentes y el grupo control en una escuela. Resultados: No hubo diferencia estadística significante (p=0,412) entre el resultado medio del grupo estudio (80,08) y control (81,99). Entre los obesos no hubo diferencia estadística (p=0,220) entre el sexo masculino ( X o = 82,83) y el femenino ( X > o = 78,51). ). Entre los eutroficos hubo diferencia estadística (p=0,016) entre el sexo masculino ( X > o = 76,90) y el femenino ( X o = 84,88). Conclusión: Los adolescentes, independiente de ser obesos o no, está buscando invertir en una amistad más íntima y fuerte. La obesidad parece afectar menos las relaciones sociales de los adolescentes masculinos.

Impact of the hypocaloryc diet using food substitute on the body wieght and biochemical profile

Recent studies using balanced hypocaloric diets with food substitutes in some meals, have presented positive results. There are no studies with the Brazilian population on the efficacy of using food substitute, together with a hypocaloric diet. Main objective of this study was to verify the effects of a hypocaloric diet using food substitutes as meal replacement on the body weight, lipid profile, and glucose and insulin plasma levels. Seventy eight subjects of both genders were selected, 20-50 years old, and a body weight index between 25 kg/m2 and 35 kg/m2. The study lasted for six months and it was divided in 2 phases of three months each- mass reduction for 3 months and 3 months for maintenance. The sample was randomly divided in two groups: Group A (control- 3 months of general nutritional and physical orientation followed by 3 months with 1 meal replacement) and Group B (intervention- 2 meals replacement a day plus nutritional and physical orientation for 3 months followed by 3 months with 1 meal replacement).Anthropometric measurements, percent body fat (per cent BF), biochemical profile and intake survey were performed at moments 0, 3 and 6 months. Both groups showed a significant decrease in per cent BF, weight, and consequently in their BMI, in the third and sixth month of follow up. However, weight loss in group B was higher than in group A. At the end of the treatment, 0 and 25.0 per cent of the patients of the group A and B, respectively, presented a weight loss higher than 10 per cent of the initial weight. Comparing the triglycerides, LDL-cholesterol and glucose levels, between the beginning and after the three and six months of treatment, there was a significant reduction in the individuals only in group B. In conclusion, the use of food substitutes as meal replacement, together with a balanced, hypocaloric diet, proved to be efficient in weight loss for Brazilian overweighed individuals

Impact of the hypocaloric diet using food substitutes on the body weight and biochemical profile.

Recent studies using balanced hypocaloric diets with food substitutes in some meals, have presented positive results. There are no studies with the Brazilian population on the efficacy of using food substitute, together with a hypocaloric diet. Main objective of this study was to verify the effects of a hypocaloric diet using food substitutes as meal replacement on the body weight, lipid profile, and glucose and insulin plasma levels. Seventy eight subjects of both genders were selected, 20-50 years old, and a body weight index between 25 kg/m2 and 35 kg/m2. The study lasted for six months and it was divided in 2 phases of three months each- mass reduction for 3 months and 3 months for maintenance. The sample was randomly divided in two groups: Group A (control- 3 months of general nutritional and physical orientation followed by 3 months with 1 meal replacement) and Group B (intervention- 2 meals replacement a day plus nutritional and physical orientation for 3 months followed by 3 months with 1 meal replacement). Anthropometric measurements, percent body fat (%BF), biochemical profile and intake survey were performed at moments 0, 3 and 6 months. Both groups showed a significant decrease in %BF, weight, and consequently in their BMI, in the third and sixth month of follow up. However, weight loss in group B was higher than in group A. At the end of the treatment, 0 and 25.0% of the patients of the group A and B, respectively, presented a weight loss higher than 10% of the initial weight. Comparing the triglycerides, LDL-cholesterol and glucose levels, between the beginning and after the three and six months of treatment, there was a significant reduction in the individuals only in group B. In conclusion, the use of food substitutes as meal replacement, together with a balanced, hypocaloric diet, proved to be efficient in weight loss for Brazilian overweighed individuals.