Body Composition In Obese Adolescents Research Articles

Effect of Orlistat on Weight and Body Composition in Obese Adolescents

The prevalence of overweight and obesity in children and adolescents is increasing rapidly. In this population, behavioral therapy alone has had limited success in providing meaningful, sustained weight reduction, and pharmacological treatment has not been extensively studied. To determine the efficacy and safety of orlistat in weight management of adolescents. Multicenter, 54-week (August 2000-October 2002), randomized, double-blind study of 539 obese adolescents (aged 12-16 years; body mass index [BMI] >or=2 units above the 95th percentile) at 32 centers in the United States and Canada. A 120-mg dose of orlistat (n = 357) or placebo (n = 182) 3 times daily for 1 year, plus a mildly hypocaloric diet (30% fat calories), exercise, and behavioral therapy. Change in BMI; secondary measures included changes in waist and hip circumference, weight loss, lipid measurements, and glucose and insulin responses to oral glucose challenge. There was a decrease in BMI in both treatment groups up to week 12, thereafter stabilizing with orlistat but increasing beyond baseline with placebo. At the end of the study, BMI had decreased by 0.55 with orlistat but increased by 0.31 with placebo (P = .001). Compared with 15.7% of the placebo group, 26.5% of participants taking orlistat had a 5% or higher decrease in BMI (P = .005); 4.5% and 13.3%, respectively, had a 10% or higher decrease in BMI (P = .002). At study end, weight had increased 0.53 kg with orlistat and 3.14 kg with placebo (P<.001). Dual-energy x-ray absorptiometry showed that this difference was explained by changes in fat mass. Waist circumference decreased in the orlistat group but increased in the placebo group (-1.33 cm vs +0.12 cm; P<.05). Generally mild to moderate gastrointestinal tract adverse events occurred in 9% to 50% of the orlistat group and in 1% to 13% of the placebo group. In combination with diet, exercise, and behavioral modification, orlistat statistically significantly improved weight management in obese adolescents compared with placebo. The use of orlistat for 1 year in this adolescent population did not raise major safety issues although gastrointestinal adverse events were more common in the orlistat group.

Exercise training normalizes vascular dysfunction and improves central adiposity in obese adolescents

ObjectivesWe sought to characterize the impact of obesity on vascular function in adolescents and to determine whether an exercise program reverses abnormalities in endothelial function. BackgroundObesity, a major modifiable risk factor for cardiovascular disease, is epidemic in Western societies, with rapid rates of increase in the young. Atherosclerosis begins in childhood, and endothelial dysfunction is its earliest detectable manifestation. MethodsThe influence of eight weeks of circuit training (CT) was examined in 19 obese subjects (14.3 ± 1.5 years), using a randomized, crossover protocol. Functional capacity and muscular strength were assessed by standard techniques. Body composition was examined using anthropometric measures and dual-energy X-ray absorptiometry. Conduit vessel endothelial function was assessed using high-resolution ultrasound and flow-mediated dilation (FMD) of the brachial artery. ResultsCircuit training decreased abdominal and trunk fat and significantly improved fitness and muscular strength (p < 0.05). In the obese group, FMD was significantly impaired relative to control subjects (n = 20) at entry (5.3 ± 0.9% vs. 8.9 ± 1.5%, p < 0.05) and was normalized after CT (8.8 ± 0.8%, p < 0.05). ConclusionsCircuit training improved functional capacity, muscular strength, and body composition in obese adolescents. Furthermore, conduit vessel function was normalized after exercise training. If vascular dysfunction is an integral component of the pathogenesis of vascular disease, this study supports the value of an exercise program in the management of obese adolescents.

Effects of a multidisciplinary weight loss intervention on body composition in obese adolescents

To investigate if a multidisciplinary weight loss program in adolescents suffering severe obesity allows adequate growth and development and avoid lean mass loss. A total of 55 adolescents (33 girls and 22 boys) suffering severe obesity were enrolled in an interdisciplinary weight reduction program lasting 6-12 months. Progressive submaximal physical activity was performed and national dietary allowances for adolescents with low levels of physical activity energy were provided. Total and segmental body composition was assessed by means of dual-energy X-ray absorptiometry. The mean height significantly increased (P<0.001). The mean body mass index (BMI) dropped in boys from 34.5+/-3.2 to 25.5+/-2.3 kg/m(2) and in girls from 38.4+/-4.1 to 28.4+/-4.1 kg/m(2). Height increased according to the expected pattern (P<0.001). Total lean mass (LM) did not vary and was positively correlated to pubertal development in both sexes before and after weight loss. Steepest drop in fat mass (FM) was observed in the trunk (-63.2+/-10.1% in boys and -51.5+/-11.4% in girls). Decrease in BMI and FM was tightly correlated in both sexes. However, slopes significantly differed (P<0.0005) so that a decrease of 1 kg/m(2) in BMI corresponded to a decrease of 3.92 kg in FM in girls and of 5.44 kg in boys. In each sex, FM at baseline and duration of the treatment were the main determinants of the decrease in FM. During adolescence, despite a major weight loss, adequate growth and preservation of LM can be achieved. Weight loss kinetics markedly differs between boys and girls. Low-calorie diets are unnecessary to achieve a marked reduction of severe obesity during puberty.

Exercise training normalises vascular function and improves body composition in obese adolescents

Exercise training normalises vascular function and improves body composition in obese adolescents

Effects of moderate exercise and nutritional guidance on body composition of obese adolescents assessed by bone densithometer (dexa)

Este estudo foi desenvolvido com a finalidade de avaliar o efeito da atividade física moderada, associada à orientação nutricional, sobre a composição corporal de adolescentes obesos, para esse propósito, 11 adolescentes (7 = 12,8 anos) foram submetidos a exercício aeróbio (cicloergômetro - 60% FC máx), em duas sessões semanais, durante nove meses, sendo avaliada a composição corporal por Densitometria Óssea antes e após o período de treinamento. Os valores iniciais (I) e finais (F) para as variáveis antropométricas e da composição corporal foram: IMC (I: 33,3 ± 5,2; F: 31,8 ± 6,9* kg/m2); percentual de gordura corporal (I: 48,5 ± 6,7; F: 47,2 ±5,1* %); peso de massa magra (I: 40,6 ± 4,9; F- 42,5 ± 5,4* kg). Tais resultados indicam que, houve um aumento significativo no peso da massa magra e reduções na porcentagem de gordura corporal e no índice de Massa Corpórea (IMC). Isto sugere um provável efeito do programa de treinamento e da orientação nutricional. As adaptações observadas no presente estudo nos permitem sugerir que o exercício aeróbio e a orientação nutricional podem promover importantes adaptações sobre a composição corporal de adolescentes obesos, atenuando os efeitos adversos decorrentes da obesidade

Effect of a weight-reducing high-protein diet on the body composition of obese adolescents.

The effect of a three-month period on a high-protein reducing diet on body composition was studied in 17 obese adolescents, aged 12.5 to 17.4 years. Body composition was assessed by estimating fat-free body mass from four skin-fold thicknesses, total body potassium by natural potassium 40 abundance, and total body nitrogen by prompt gamma ray analysis. Weight loss was 15% of initial body weight. Total body nitrogen loss was only 4.8% (not significant), while total body potassium fell by 13.2%. Change in fat-free body mass estimated from skin-fold thicknesses constituted approximately 44% of the total weight lost. There was no correlation between changes in total body potassium and total body nitrogen, suggesting that total body potassium cannot be used to predict total body nitrogen in a changing nutritional state.