The school environment is often the focus of healthy eating and physical activity policies intended to address childhood obesity. However, students are usually excluded from the development and implementation of such policies. The purpose of this study was to explore grade nine student perspectives regarding: supports and barriers to healthy eating and physical activity at school; strategies for improving the school nutrition and physical activity environments; and potential student contribution to the development, implementation, and evaluation of school-based policies. A qualitative approach utilizing focus groups and photovoice with 30 students from two schools in southern Alberta was used to collect data. Major themes included: access to healthy food choices; teacher influences; peer influences; access to physical activity opportunities; impact of marketing; and conflicting messages. Students can provide valuable insights to policy development, implementation and evaluation. Implications for future research and policy development are reviewed. / xi, 179 leaves : ill. ; 29 cm

O excesso de gordura corporal esta associado a diversas doenças de ordem metabólica, psicológica e estrutural. É indicado que a adolescência é o período crítico para o desenvolvimento de hábitos associados ao acúmulo de gordura como a inatividade física, má alimentação e sedentarismo. Desta forma, esta é uma fase crítica para o monitoramento da população visando a redução de casos de obesidade e doenças associadas. A técnica padrão-ouro para avaliação da gordura corporal é a absorciometria de raios-X de dupla-energia. Porém seu caráter laboratorial impede o uso amplo. Desta forma, técnicas mais simples, como a medição de dobras cutâneas devem ser modeladas a partir de técnicas mais exatas para este monitoramento. Os modelos existentes foram desenvolvidos com populações estrangeiras que não se assemelham aos habitantes da Região Metropolitana de Curitiba o que pode levar a erros de avaliação e diagnóstico. Desta forma o objetivo deste estudo é produzir um modelo de análise da gordura corporal apropriado a crianças e adolescentes da Região Metropolitana de Curitiba. Foram selecionadas duas amostras, uma composta por 567 adolescentes hígidos com idade entre 10 e 18 anos; e outra composta por 63 crianças com paralisia cerebral entre 3 e 10 anos. Os dois grupos possuíam indivíduos de ambos os sexos. Foram coletados dados de massa, estatura, idade e espessura de dobras cutâneas, além da avaliação de composição corporal por densitometria radiológica. O percentual de gordura obtido por diferentes equações de dobras cutâneas e demais medidas antropométricas entre os adolescentes foi comparado com o obtido por densitometria indicando associações abaixo do indicado (CCC<0,900). Foi encontrada também uma tendência de subestimação pelas dobras cutâneas, o que resultava em elevados valores de especificidade e baixos de sensibilidade (sendo especificidade á quantidade relativa de verdadeiros negativos entre quem não possui a condição clínica, e a sensibilidade a relação de verdadeiros positivos entre quem possui a condição considerada). Isto indica uma grande quantidade de falsos negativos o que leva muitos adolescentes com excesso de gordura a serem classificados como eutróficos. O modelo classificatório desenvolvido para adolescentes obteve um ajuste de R2 Negelkerke=0,829, sensibilidade de 99,0% e especificidade de 82,7% apresentando indicadores diagnósticos acima do obtido por equações de dobras cutâneas e IMC. Para as crianças com paralisia cerebral foi desenvolvido um modelo estimativo da massa de gordura com ajuste de R2 =0,950 com erro padrão de estimativa de 1,039. As equações utilizadas para converter as dobras cutâneas em medições da gordura corporal demonstraram-se inadequadas para aplicação em adolescentes da região metropolitana de Curitiba. A aplicação de técnicas de regressão logística e linear apresentou resultados positivos, mesmo a partir da modelagem na amostra de crianças com paralisia cerebral. / The overfat is associated with many methabolic, psycological and structural diseases. The adolescence is indicated as the critical period for the development of habits associated with fat accumulation like physical inactivity, poor diet and sedentarism. Thus, this is a important moment to monitorig the population aiming the reduction of obesity and associated disease. The golden standard to evaluate the body fatness is the dual-energy x-ray absorptiometry. However, its laboratorial aspect prevents a wide use. This way, simpler techniques as the skinfold measurement should be model from more exact techniques for this monitoring. The existing models were developed with foreign populations that don't resemble the Curitiba Metropolitan Region habitants. This could lead to evaluation and diagnostic errors. Thus, the aim of this study is to product a model of body fatness analysis appropriate to children and adolescents from the Curitiba Metropolitan Region. Two sample were selected, the first one composed by 567 healthy adolescents aged between 10 and 18 years; the other one composed by 63 children with cerebral palsy between 3 and 10 years. The groups have both genders. The data of weight, height, age and skinfold thickness were collected, beyond the body composition evaluation by radiologic densitometry. The fatness percentage obtained by different skinfold and other anthopometric mesures equations among the adolescents was compared with the obtained by densitometry presenting associations below indicated (CCC<0,900). A tendency of underestimation by the skinfold equations was found, that resulted in higher specificity values and low sensitivity (being specificity the relative quantity of true negatives among those who do not have de clinical condition, and the sensitivity the relations of true positives amons those who have the considered condition). This indicates a major quantitaty of false negatives, that leads many overfat adolescents to be classify as eutrophic. The developed classificatory model for adolescents obtained an adjustment of R2 Negelkerke=0,829, sensitivity of 99,0% and specificity of 82,7% presenting diagnostic's indicators above that obtained by skinfold equations and BMI. For the children with cerebral palsy was developed a fat mass estimation model with adjustment of R2 =0,950 and standard error of estimative of 1,039. The equations used to convert the skinfold in body fatness measures were found to be inadequate for aplication in adolescents from Curitiba Metropolitan Region. The aplication of logistic and linear regression techniques have presented positive results, even from modeling in the children with cerebral palsy sample.

Dietary intake is a strong determinate of the health of an individual. Healthy eating is an important prevention to non-communicable diseases. If behaviour is to be changed insight into what the attitudes and barriers are to eating healthily amongst adolescents is imperative. This can provide knowledge for future prevention campaigns for healthy eating to prevent overweight and obesity. The purpose of the study was to quantitatively describe what attitudes adolescent females have towards healthy eating and what potential barriers omits them from adopting healthy eating behaviours. Data collection was done using structured questionnaires. Girls (N=73) from 3 public all girls’ high schools within Durban, KZN, participated in this study. The findings revealed that overall adolescent girls have a positive attitude to healthy eating. A lack of time, the foods sold in the school shop and the conveniences of less healthy food have been identified as barriers to healthy eating. / Health Studies / M.A. (Public Health)

MSCNPT / Department of Nutrition / Context: A survey made worldwide (including South Africa) revealed that most teenagers are overweight and obese and that they eat little nutritious food. Obesity and overweight are public health problems and need to be addressed from a community perspective. The reason for exploring this problem in this study was that South Africa has one of the highest rates of overweight and obesity in the world among urban and rural black women. Objective: Investigating the eating and lifestyle habits of overweight and obese female teenagers in Thulamela Local Municipality, Limpopo province, South Africa. Design, setting and participants: This was an exploratory, descriptive study conducted in 2006–2007 amongst 125 female teenagers aged 13 to 18 years from rural schools in Thulamela Local Municipality. A hundred and twenty-five questionnaires were completed and data were gathered on the demographics, social and lifestyle habits, nutrition-related problems, dietary patterns and dietary history of the participants. Measurements: Eating and lifestyle habits, physical activity, meaning of healthy and unhealthy dietary habits, weight, height and body mass index were measured. Results: Seventy percent of the respondents actively consumed three meals in a day, 83% consumed starchy snacks between meals, whilst 72% of the respondents carried lunchboxes to school. Regarding lifestyle habits, 88% of the respondents slept more hours than recommended (8 hours) 88% performed sedentary activities and 66% did physical activities such as walking. Conclusion: The results pointed out unhealthy eating and lifestyle habits influencing teenagers’ weight. Identified factors must be considered in order to develop tailored nutrition interventions to improve teenagers’ consciousness about adopting a healthy lifestyle. / NRF

by Wan Cheuk Wing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves p. 166-183). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii-iii / Abstract (Chinese Version) --- p.iv / Table of Contents --- p.v-xi / List of Figures --- p.xii / List of Tables --- p.xiii-xxiii / List of Abbreviations --- p.xxiiv / Chapter CHAPTER ONE: --- INTRODUCTION / Chapter 1.1 --- "Socioeconomic, dietary and epidemiological transformation" --- p.1 / Chapter 1.1.1 --- Low breastfeeding rate --- p.3 / Chapter 1.1.2 --- Breakfast skipping --- p.6 / Chapter 1.1.3 --- Popularity of eating out --- p.8 / Chapter 1.1.4 --- Lack of school lunch surveillance or policy --- p.10 / Chapter 1.1.5 --- Frequent unhealthy snack consumption --- p.11 / Chapter 1.1.6 --- Physical inactivity --- p.12 / Chapter 1.2 --- "Childhood and Adolescent obesity determinants, trends and consequences" --- p.13 / Chapter 1.3 --- "Physiological, psychosocial and economic determinants of childhood and adolescent obesity" --- p.16 / Chapter 1.4 --- Adolescence - Critical period of habit development --- p.17 / Chapter 1.4.1 --- "Factors affecting eating and physical activity patterns: peers, television and the school environment" --- p.18 / Chapter 1.5 --- The education system in Hong Kong and United States --- p.20 / Chapter 1.5.1 --- Principles of effective nutrition curriculum development --- p.23 / Chapter 1.6 --- Study Design and Theoretical Approach of study --- p.23 / Chapter CHAPTER TWO: --- METHODOLOGY / Chapter 2.1 --- Target Population Determination --- p.28 / Chapter 2.2 --- Recruitment & Geographical Distribution of Schools --- p.28 / Chapter 2.2.1 --- Familiarization with School Background --- p.30 / Chapter 2.3 --- Focus groups --- p.31 / Chapter 2.4 --- "Questionnaire Development, Instrument Design and Pre-testing" --- p.32 / Chapter 2.4.1 --- Questionnaire Development --- p.32 / Chapter 2.4.2 --- Socio-demographic --- p.33 / Chapter 2.4.3 --- Breastfeeding --- p.33 / Chapter 2.4.4 --- "Dietary - Healthy Diet Pyramid, Healthy Breakfast, Healthy Lunch, Healthy Snack, Healthy Eating Out" --- p.33 / Chapter 2.4.5 --- Physical Activity --- p.34 / Chapter 2.4.6 --- Pretesting --- p.35 / Chapter 2.4.7 --- Sampling Method --- p.35 / Chapter 2.4.8 --- Student Helpers Training --- p.36 / Chapter 2.4.9 --- Data Collection --- p.37 / Chapter 2.4.10 --- Fun-In-Seven Logo --- p.37 / Chapter 2.5 --- Intervention Program --- p.38 / Chapter 2.5.1 --- Planning the Intervention Programs - Health Committee Establishment --- p.38 / Chapter 2.5.2 --- "Intervention Activities, Curriculum Design and Implementation" --- p.39 / Chapter 2.6 --- Evaluations --- p.45 / Chapter 2.6.1 --- Process Evaluation --- p.45 / Chapter 2.6.2 --- Outcome Evaluation --- p.45 / Chapter 2.7 --- Data Management --- p.46 / Chapter 2.7.1 --- Data Processing --- p.46 / Chapter 2.7.2 --- Statistics --- p.46 / Chapter 2.7.3 --- Data Analysis --- p.47 / Chapter CHAPTER THREE: --- RESULTS / Chapter 3.1 --- Participation rate of the study --- p.52 / Chapter 3.2 --- Pre-intervention survey results --- p.52 / Chapter 3.2.1 --- General sociodemographic characteristics of students --- p.52 / Chapter 3.2.2 --- Self-evaluated nutrition scores --- p.53 / Chapter 3.2.3 --- Breastfeeding --- p.55 / Chapter 3.2.4 --- Healthy Diet Pyramid --- p.61 / Chapter 3.2.5 --- Healthy breakfast awareness and practices --- p.64 / Chapter 3.2.6 --- "Eating out knowledge, attitudes and practices" --- p.68 / Chapter 3.2.7 --- Healthy Lunch --- p.73 / Chapter 3.2.8 --- Snack patterns --- p.77 / Chapter 3.2.9 --- Physical Activity --- p.81 / Chapter 3.2.10 --- Summary Profile of the Secondary Students in the Pre-intervention Survey --- p.92 / Chapter 3.3 --- Outcome evaluation --- p.95 / Chapter 3.4 --- Post-intervention Survey --- p.95 / Chapter 3.4.1 --- General sociodemographic characteristics of students --- p.95 / Chapter 3.4.2 --- Changes in self-rated nutrition knowledge --- p.96 / Chapter 3.4.3 --- Intervention effects on of breastfeeding knowledge and attitudes --- p.97 / Chapter 3.4.4 --- Healthy Diet Pyramid and healthy eating awareness --- p.104 / Chapter 3.4.5 --- Breakfast --- p.109 / Chapter 3.4.6 --- Eating Out --- p.113 / Chapter 3.4.7 --- Lunch --- p.117 / Chapter 3.4.8 --- Snacking --- p.121 / Chapter 3.4.9 --- Physical Activity --- p.128 / Chapter 3.4.10 --- "Changes in students' knowledge, attitude, and behavior after the intervention programme" --- p.140 / Chapter 3.5 --- Summary Profile of the Secondary Students in the Post-intervention Survey --- p.145 / Chapter CHAPTER FOUR: --- DISCUSSION / Chapter 4.1 --- Impacts of Fun-in-Seven programmes --- p.150 / Chapter 4.1.1 --- Breastfeeding --- p.150 / Chapter 4.1.2 --- Healthy Diet Pyramid --- p.151 / Chapter 4.1.3 --- Healthy Breakfast --- p.152 / Chapter 4.1.4 --- Lunch --- p.153 / Chapter 4.1.5 --- Snacking --- p.155 / Chapter 4.1.6 --- Physical Activity --- p.156 / Chapter 4.2 --- Strengths of the intervention programme --- p.157 / Chapter 4.3 --- Limitations and problems encountered --- p.159 / Chapter 4.4 --- Recommendations for further improvement --- p.161 / Chapter CHAPTER FIVE: --- CONCLUSION --- p.165 / References --- p.166-180 / Appendices / Chapter A --- Questionnaire for Teacher/Principal (English version) --- p.181-183 / Chapter B --- Secondary School Background Information (English version) --- p.184-195 / Chapter CI --- Questionnaire (Chinese version) --- p.196-209 / Chapter CII --- Questionnaire (English version) --- p.210-224 / Chapter D --- Pamphlets for seven themes (Chinese and English versions) --- p.225-257 / Chapter E --- Worksheets & Certificates (Chinese and English versions) --- p.258-283 / Chapter F --- Activities photos (English version) --- p.284-288 / Chapter G --- Summary of materials and activities of each theme in Fun-in-Seven (Chinese version) --- p.289 / Chapter HI --- Breastfeeding and Physical Activity Process Evaluation Questionnaire (Chinese version) --- p.290-291 / Chapter HII --- Breastfeeding and Healthy Diet Pyramid Process Evaluation Questionnaire (English version) --- p.292-294 / Chapter JI --- "Physical Activity, Breakfast, Lunch, Eat Out, Snack Outcome Evaluation (Chinese version) - School 1" --- p.295-299 / Chapter JII --- "Physical Activity, Breakfast, Lunch, Eat Out, Snack Outcome Evaluation (English version)" --- p.300-305 / Chapter KI --- "Physical Activity, Breakfast, Lunch, Eat Out, Snack Outcome Evaluation (Chinese version) - School 2" --- p.306-309 / Chapter KII --- "Physical Activity, Breakfast, Lunch, Eat Out, Snack Outcome Evaluation (English version) ´ؤ School 2" --- p.310-313 / Chapter LI --- "Physical Activity, Breakfast, Lunch, Eat Out, Snack Outcome Evaluation (Chinese version) ´ؤ School 3" --- p.314-317 / Chapter LII --- "Physical Activity, Breakfast, Lunch, Eat Out, Snack Outcome Evaluation (English version) ´ؤ School 3" --- p.318-322 / Chapter MI --- Teacher's Outcome Evaluation Form (Chinese version) ´ؤ School --- p.323-324 / Chapter MII --- Teacher's Outcome Evaluation Form (English version) 一 School --- p.325-327 / Chapter NI --- Teacher's Outcome Evaluation Form (Chinese version) ´ؤ School --- p.328-329 / Chapter NII --- Teacher's Outcome Evaluation Form (English version) - School --- p.330-332 / Chapter PI --- Teacher's Outcome Evaluation Form (Chinese version) - School --- p.333-334 / Chapter PII --- Teacher's Outcome Evaluation Form (English version) 一 School --- p.335-337 / Chapter QI --- Health Ambassador's Outcome Evaluation Form (Chinese version) --- p.338-339 / Chapter QII --- Health Ambassador's Outcome Evaluation Form (English version) --- p.340-341

Due to the fact that there has been a dramatic increase in the number of adolescents with unhealthy eating habits there is a growing recognition on the part of professionals, educators and parents for the development and implementation of an intervention programme for the facilitation of healthy eating habits. Relevant literature on eating behaviour indicated that low self-concept is associated with health compromising behaviours such as unhealthy eating habits. The nature of self-concept and eating habits was explained in order to determine important exogenous and endogenous factors as well as perspectives to use as a background for the development of a Psychoeducational intervention programme. Theoretical principles and practical applications of cognitive-behaviour therapy and hypnotherapy were analysed and used as a foundation for the development of the intervention programme. The researcher developed an Interactionism Model of Self-concept and Eating habits and a Psycho-educational programme involving cognitive-behaviour therapy and hypnotherapy to improve eating habits of adolescents. Valid and reliable measuring instruments were used in order to measure self-concept and eating habits. A pre-test post-test design was implemented to nine participants using the Adolescent Self-concept Scale (ASCS), Eating Habits Questionnaire for Adolescents (EHQA) developed by the researcher (2001) and Body Mass Index (BMI). Diagnostic measuring instruments also included the Emotions Profile Index (EPI), Draw A Person (DAP), Sentence Completion, Dietary Record and interview. Results from the empirical study indicated that adolescents with low self-concept and unhealthy eating habits responded positively to the Psycho-educational programme involving cognitive-behaviour and hypnotherapy. Specifically, there was a significant increase in selfconcept and a satisfactory improvement in eating habits. Recommendations for psychotherapy practice, educators and parents were made, based on the current research results. The contribution of the study lies in the fact that a hands-on practical implementation of the Psycho-educational programme was developed to facilitate the improvement of eating habits and it further contributes to the psychological well-being and healthy life-style of adolescents having positive implications for society. / Educational Studies / D.Ed. (Psychology of Education)

Due to the fact that there has been a dramatic increase in the number of adolescents with unhealthy eating habits there is a growing recognition on the part of professionals, educators and parents for the development and implementation of an intervention programme for the facilitation of healthy eating habits. Relevant literature on eating behaviour indicated that low self-concept is associated with health compromising behaviours such as unhealthy eating habits. The nature of self-concept and eating habits was explained in order to determine important exogenous and endogenous factors as well as perspectives to use as a background for the development of a Psychoeducational intervention programme. Theoretical principles and practical applications of cognitive-behaviour therapy and hypnotherapy were analysed and used as a foundation for the development of the intervention programme. The researcher developed an Interactionism Model of Self-concept and Eating habits and a Psycho-educational programme involving cognitive-behaviour therapy and hypnotherapy to improve eating habits of adolescents. Valid and reliable measuring instruments were used in order to measure self-concept and eating habits. A pre-test post-test design was implemented to nine participants using the Adolescent Self-concept Scale (ASCS), Eating Habits Questionnaire for Adolescents (EHQA) developed by the researcher (2001) and Body Mass Index (BMI). Diagnostic measuring instruments also included the Emotions Profile Index (EPI), Draw A Person (DAP), Sentence Completion, Dietary Record and interview. Results from the empirical study indicated that adolescents with low self-concept and unhealthy eating habits responded positively to the Psycho-educational programme involving cognitive-behaviour and hypnotherapy. Specifically, there was a significant increase in selfconcept and a satisfactory improvement in eating habits. Recommendations for psychotherapy practice, educators and parents were made, based on the current research results. The contribution of the study lies in the fact that a hands-on practical implementation of the Psycho-educational programme was developed to facilitate the improvement of eating habits and it further contributes to the psychological well-being and healthy life-style of adolescents having positive implications for society. / Educational Studies / D.Ed. (Psychology of Education)

Introdução: Estudos têm encontrado uma transição da obesidade da população adulta para crianças e adolescentes, que por sua vez, pode acarretar manifestações clínicas, como: doenças coronarianas, diabetes tipo 2, e complicações psicossociais cada vez mais precocemente. Contudo, métodos para avaliação da composição corporal para essa faixa etária, principalmente envolvendo técnicas de baixo custo como as medidas de dobras cutâneas (DC) apresentam imprecisões em estudos brasileiros. Fator o qual pode levar a uma interpretação equivocada da composição corporal dos avaliados. Objetivo: desenvolver novos modelos matemáticos utilizando medidas de DC, tendo como referência a absorciometria de raios-X de dupla energia (DXA), para estimativa de massa de gordura (G) em adolescentes. Métodos: Trata-se de um estudo exploratório descritivo onde foram avaliados 416 adolescentes do gênero masculino de 12 a 17 anos, sendo 42 destinados para compor a amostra de validação da pesquisa. Foram coletadas medidas de massa corporal total, estatura, circunferência da cintura e quadril, nove pontos anatômicos baseados em DC: bíceps, tríceps, subescapular, peitoral, axilar média, abdominal, supra-ilíaca, coxa e panturrilha, além da G e densidade mineral óssea (DMO) aferida com a tecnologia de DXA. Para o desenvolvimento das equações foi utilizado um modelo de regressão linear múltipla através do método de mínimos quadrados ordinários (OLS). Resultados: O grupo apresentou índice de massa corporal (IMC) médio de 21,25±4,12kg/m² e %G = 20,57±5,80%. A partir do %G, a prevalência de excesso de gordura foi verificada em 38,3% dos adolescentes. O impacto da gordura na DMO dos adolescentes indicou uma associação na ordem de r = -0,358; p<0,005, sendo verificada redução de até 14% da DMO para a região da coluna em adolescentes com obesidade em comparação aos eutróficos. O desenvolvimento de novos modelos matemáticos que atendessem critérios de alto coeficiente de determinação (R²), baixo erro padrão de estimativa (EPE), controle de colinearidade, normalidades dos resíduos, homoscedasticidade e praticidade, possibilitaram a apresentação de três opções com R² = 0,932 e EPE 1,79; R² = 0,912 e EPE = 1,78; R² = 0,850 e EPE = 1,87, respectivamente. Em todas as opções, as variáveis idade e estatura foram empregadas, bem como as DC de tríceps e subescapular. Conclusão: Os resultados obtidos evidenciam a possibilidade de desenvolvimento de novos modelos matemáticos para a avaliação da gordura corporal em adolescentes com resultados superiores aos modelos existentes na literatura. / Introduction: Studies have found a transition from obesity of the adult population to children and adolescents, which in turn, can lead to clinical manifestations, such as: coronary diseases, type 2 diabetes, and psychosocial complications increasingly early. However, methods for evaluating nutritional status for this age group, mainly involving low cost techniques such as skinfold thickness measurements (ST), are imprecise in Brazilian studies. Factor which can lead to a mistaken interpretation of the body composition of the evaluated ones. Objective: To develop new mathematical models, based on DC measurements, based on dual energy X-rays absorptiometry (DXA), to estimate fat mass (G) in adolescents. Methods: This was an exploratory descriptive study in which 416 male adolescents aged 12 to 17 years were evaluated, 42 of whom were separated to compose the study validation sample. Measurements of total body mass, stature, waist and hip circumference were obtained, nine anatomical points based on ST: biceps, triceps, subscapular, pectoral, mid axillary, abdominal, suprailiac, thigh and calf muscles, as well as G and bone mineral density (BMD) measured with DXA technology. For the development of the equations, a multiple linear regression model was used by the ordinary least square (OLS) method. Results: The group had a mean body mass index (BMI) of 21.25± 4.12 kg / m² and %G = 20.57 ± 5.80%. From %G, the prevalence of excess fat was verified in 38.3% of adolescents. The impact of fat on adolescent BMD indicated an association in the order of r = -0.358; P <0.005, with BMD reduction up to 14% for the spine region in adolescents with obesity compared to eutrophic. The development of new mathematical models that meet criteria of high coefficient of determination (R²), low standard error of estimation (SEE), control of colinearity, residue normalities, homoscedasticity and practicality, allowed the presentation of three options with R² = 0.932 and SEE 1.79; R² = 0.912 and SEE = 1.78; R² = 0.850 and SEE = 1.87, respectively. In all the options, the variables age and height were employed, as well as triceps and subscapular ST. Conclusion: The results obtained evidenced the possibility of developing new mathematical models for the evaluation of body fat in adolescents with results superior to the existing models in the literature.

Introdução: Estudos têm encontrado uma transição da obesidade da população adulta para crianças e adolescentes, que por sua vez, pode acarretar manifestações clínicas, como: doenças coronarianas, diabetes tipo 2, e complicações psicossociais cada vez mais precocemente. Contudo, métodos para avaliação da composição corporal para essa faixa etária, principalmente envolvendo técnicas de baixo custo como as medidas de dobras cutâneas (DC) apresentam imprecisões em estudos brasileiros. Fator o qual pode levar a uma interpretação equivocada da composição corporal dos avaliados. Objetivo: desenvolver novos modelos matemáticos utilizando medidas de DC, tendo como referência a absorciometria de raios-X de dupla energia (DXA), para estimativa de massa de gordura (G) em adolescentes. Métodos: Trata-se de um estudo exploratório descritivo onde foram avaliados 416 adolescentes do gênero masculino de 12 a 17 anos, sendo 42 destinados para compor a amostra de validação da pesquisa. Foram coletadas medidas de massa corporal total, estatura, circunferência da cintura e quadril, nove pontos anatômicos baseados em DC: bíceps, tríceps, subescapular, peitoral, axilar média, abdominal, supra-ilíaca, coxa e panturrilha, além da G e densidade mineral óssea (DMO) aferida com a tecnologia de DXA. Para o desenvolvimento das equações foi utilizado um modelo de regressão linear múltipla através do método de mínimos quadrados ordinários (OLS). Resultados: O grupo apresentou índice de massa corporal (IMC) médio de 21,25±4,12kg/m² e %G = 20,57±5,80%. A partir do %G, a prevalência de excesso de gordura foi verificada em 38,3% dos adolescentes. O impacto da gordura na DMO dos adolescentes indicou uma associação na ordem de r = -0,358; p<0,005, sendo verificada redução de até 14% da DMO para a região da coluna em adolescentes com obesidade em comparação aos eutróficos. O desenvolvimento de novos modelos matemáticos que atendessem critérios de alto coeficiente de determinação (R²), baixo erro padrão de estimativa (EPE), controle de colinearidade, normalidades dos resíduos, homoscedasticidade e praticidade, possibilitaram a apresentação de três opções com R² = 0,932 e EPE 1,79; R² = 0,912 e EPE = 1,78; R² = 0,850 e EPE = 1,87, respectivamente. Em todas as opções, as variáveis idade e estatura foram empregadas, bem como as DC de tríceps e subescapular. Conclusão: Os resultados obtidos evidenciam a possibilidade de desenvolvimento de novos modelos matemáticos para a avaliação da gordura corporal em adolescentes com resultados superiores aos modelos existentes na literatura. / Introduction: Studies have found a transition from obesity of the adult population to children and adolescents, which in turn, can lead to clinical manifestations, such as: coronary diseases, type 2 diabetes, and psychosocial complications increasingly early. However, methods for evaluating nutritional status for this age group, mainly involving low cost techniques such as skinfold thickness measurements (ST), are imprecise in Brazilian studies. Factor which can lead to a mistaken interpretation of the body composition of the evaluated ones. Objective: To develop new mathematical models, based on DC measurements, based on dual energy X-rays absorptiometry (DXA), to estimate fat mass (G) in adolescents. Methods: This was an exploratory descriptive study in which 416 male adolescents aged 12 to 17 years were evaluated, 42 of whom were separated to compose the study validation sample. Measurements of total body mass, stature, waist and hip circumference were obtained, nine anatomical points based on ST: biceps, triceps, subscapular, pectoral, mid axillary, abdominal, suprailiac, thigh and calf muscles, as well as G and bone mineral density (BMD) measured with DXA technology. For the development of the equations, a multiple linear regression model was used by the ordinary least square (OLS) method. Results: The group had a mean body mass index (BMI) of 21.25± 4.12 kg / m² and %G = 20.57 ± 5.80%. From %G, the prevalence of excess fat was verified in 38.3% of adolescents. The impact of fat on adolescent BMD indicated an association in the order of r = -0.358; P <0.005, with BMD reduction up to 14% for the spine region in adolescents with obesity compared to eutrophic. The development of new mathematical models that meet criteria of high coefficient of determination (R²), low standard error of estimation (SEE), control of colinearity, residue normalities, homoscedasticity and practicality, allowed the presentation of three options with R² = 0.932 and SEE 1.79; R² = 0.912 and SEE = 1.78; R² = 0.850 and SEE = 1.87, respectively. In all the options, the variables age and height were employed, as well as triceps and subscapular ST. Conclusion: The results obtained evidenced the possibility of developing new mathematical models for the evaluation of body fat in adolescents with results superior to the existing models in the literature.

L’obésité pédiatrique est un phénomène en expansion croissante, amenant les professionnels de la santé à en parler en termes de phénomène pandémique. Mais au-delà de cette expansion croissante, c’est également l’augmentation de la sévérité de l’obésité chez l'enfant et l'adolescent qui apparaît inquiétante.<p>Or, la présence des déterminants sociaux,énergétiques, génétiques ne suffisent pas toujours pour expliquer son développement et principalement quand il s’agit d’obésité sévère. Dans le cadre de l'obésité sévère, il y a lieu de dépasser les théories centrées sur la compréhension de l’agir alimentaire pour envisager les théories qui considèrent l’implication de l’ensemble du corps dans le développement de l’obésité et ce principalement lorsqu’on s’intéresse à l’adolescent. <p><p>Les objectifs de cette étude visent, face à ces éléments, à établir, dans un premier temps, un profil démographique, médical, familial, psychologique et psychopathologique d’une population d’adolescents souffrant d'obésité sévère. Ces informations ont été recueillies à l’aide de questionnaires structurés et par observation de 164 adolescents satisfaisant aux critères de l’obésité sévère. Un diagnostic pédopsychatrique selon la CFTMEA R 2000 a été posé pour chaque sujet. Nos résultats ont souligné le déterminisme multiple de l’obésité de nos sujets mais également l’importance des comorbidités bio-psycho-sociales.<p>Dans un second temps, à l’aide d’une analyse factorielle, nous avons mis en évidence qu’une plus grande sévérité de l’obésité s’associait à des facteurs d’environnement défavorisant(troubles mentaux dans la famille, carences, maltraitance) et à la présence d'un profil psychopathologique. De plus, ces mêmes modalités étaient associées avec une compliance familiale et individuelle moins importante. <p><p>Dans une dernière partie, nous nous sommes centrés sur les liens qui unissaient ces différents éléments. Pour ce faire, nous avons aux travers d’analyse de cas et à l'aide d'un Rorschach, du Questionnaire de l'Image du Corps de Bruschon-Schweitzer, et d'un dessin de soi, évalué la présence de troubles de l’image du corps chez 10 de nos sujets et leur évolution durant la prise en charge en lien avec la perte de poids. Nos résultats ont mis en évidence la présence de troubles de l’image du corps avec une image de soi incertaine, indifférenciée aux limites diffuses. <p>L’obésité s’inscrirait en tant que garant concret face à une image du corps peu unifiée. Ceci nous permet de considérer que l’obésité s’installe au travers à la fois d’un corps peu investi, peu mobilisable imposant la nécessaire édification de barrière (l’obésité) entre le « dedans fragilisé » et le dehors vécu comme dangereux. Nous pouvons dès lors considérer la difficulté des sujets de se résoudre à une perte de poids qui ne permettrait plus au sujet de recourir à ce type de fonctionnement. <p><p>De ce fait, nous avons conclu qu'il s'agit dans la prise en charge de ces sujets de reconsidérer l’image du corps comme outil thérapeutique vecteur d’amélioration à court et à long terme. / Doctorat en Sciences Psychologiques et de l'éducation / info:eu-repo/semantics/nonPublished