RESUMO
AIMS: This study aimed to evaluate the effectiveness of the Local Authority commissioned large-scale public health service that provided a 6-week school-based weight management intervention for children aged 4-19 years. METHODS: A quantitative retrospective cohort study identified participants from 130 schools consisting of 8550 potential children aged 4-19 years across a mixture of Lower Super Output Area (LSOA) deprivation groups. Participants were invited to take part in a 5- to 12-week Healthy Lifestyles intervention with a focus on weight management delivered by OneLife Suffolk between 1 January 2017 and 1 January 2020. This resulted in a final sample of 5163 participants. The following information for each child was collected anonymously: (1) age, (2) gender, (3) preprogramme body mass index (BMI), (4) postprogramme BMI, (5) weight category and (6) LSOA category. RESULTS: Following the 6-week school-based intervention, there was a significant decrease in mean ΔBMI SDS (standardised body mass index) of -0.07 (-14.89%) among participants. Wilcoxon signed-rank test showed a significant change in weight status post 6-week weight management programme (WMP): BMI (Z = -15.87, p < .001), BMI SDS (Z = -21.54, p < .001), centile (Z = -20.12, p < .01) and weight category (Z = -7.89, p < .001), whereas Mann-Whitney U test showed no statistically significant difference in mean BMI SDS change between gender groups (p = .24) and Kruskal-Wallis test revealed no statistically significant differences in mean BMI SDS change between child LSOA groups (c2(4) = 1.67, p = .796), school LSOA groups (c2(4) = 4.72, p = .317), ethnic groups (c2(4) = 2.53, p = .640) and weight category at the start of the intervention (c2(3) = 6.20, p = .102). CONCLUSIONS: This study contributes to the growing body of evidence demonstrating the efficacy of multicomponent school-based weight management interventions and demonstrates that such interventions can be successfully implemented as part of a wider healthy lifestyles service, without widening health inequalities.
Assuntos
Obesidade Infantil , Criança , Animais , Humanos , Ovinos , Obesidade Infantil/prevenção & controle , Serviços de Saúde Escolar , Estudos Retrospectivos , Índice de Massa Corporal , Instituições AcadêmicasRESUMO
AIMS: The current study aimed to evaluate implementation fidelity of an Integrated Healthy Lifestyle Service (IHLS). METHODS: A pragmatic sample of 28 individual interviews and 11 focus groups were conducted. This resulted in a total of 81 (22 male) individuals comprising key stakeholders (n = 18), as well as intervention staff across senior management (n = 4), team lead (n = 14) and practitioner (n = 11) roles, and intervention clients (n = 34). RESULTS: A mixed degree of implementation fidelity was demonstrated throughout the five a priori fidelity domains of study design, provider training, intervention delivery, intervention receipt, and enactment. Stakeholders, staff and clients alike noted a high degree of intervention receipt across all services offered. Contrastingly, practitioners noted that they received minimal formal operational, data systems, clinical, and curriculum training as well as a lack of personal development opportunities. Consequently, practitioners reported low confidence in delivering sessions and collecting and analysing any data. A top-down approach to information dissemination within the service was also noted among practitioners which affected motivation and overall team morale. CONCLUSION: Results can be used to conceptualise best practices as a process to further strengthen the design, delivery and recruitment strategies of the IHLS.
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Estilo de Vida Saudável , Projetos de Pesquisa , Grupos Focais , Humanos , MasculinoRESUMO
OBJECTIVES: Current research in the field of childhood weight management (WM) effectiveness is hampered by inconsistent terminology and criterion for WM programme completion, alongside other engagement-related concepts (e.g. adherence, dropout and attrition). Evidence reviews are not able to determine conclusive intervention effectiveness because of this issue. This study aims to quantify how various completion criterion impacts upon on: 1) the percentage of WM completers; 2) the standardised body mass index (BMI SDS) reduction; and 3) the predictors of WM completion. STUDY DESIGN: A methodological, sensitivity analysis to examine how differential completion criterion affect programme outcomes and predictors. METHODS: Secondary data of 2948 children were used. All children attended a MoreLife WM programme between 2009 and 2014. The completion criterion was incrementally adjusted by 10% (i.e. completer attends 10%, 20%, 30%... of sessions) for research aims 1-2, with the percentage of completers and change in BMI SDS calculated at each increment. For aim 3, the stability (strength, direction and significance) of the predictors were examined when using the completion criterion of four alternative studies against our previous study (completion ≥70% attendance). RESULTS: The volume of programme completers decreased in a linear manner as the completion criterion became more stringent (i.e. 70-100% attendance). The change in BMI SDS conversely became incrementally greater. The strength, direction and significance of the predictors was highly dependent on the completion criterion; the odds ratio varied by 24.2% across a single predictor variable (delivery period). The degree of change is evidenced in the paper. CONCLUSIONS: Inconsistent completion criterion greatly limits the synthesis of programme effectiveness and explains some of the inconsistency in the predictors of engagement. Standardised criterion for engagement-related terminology are called for.
Assuntos
Índice de Massa Corporal , Manutenção do Peso Corporal , Avaliação de Programas e Projetos de Saúde/normas , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , MasculinoRESUMO
Childhood obesity is a major public health concern; behavioural interventions induce weight reduction in some, but success is variable. Heart rate variability (HRV) has been associated with impulse control and extent of dieting success. This study investigated the relationship between HRV and post childhood obesity intervention weight-management success, and involved recording the frequency-domain HRV measures ratio between low frequency and high frequency power (LF/HF) and high frequency power (HF), and the time-domain measure, percentage of successive beat-to-beat intervals that differ by more than 50ms (PNN50). It was expected that greater LF/HF and lower HF would be associated with greater post-intervention weight gain, and that greater PNN50 would be associated with greater impulse control. Seventy-four participants aged 9-14 (M=10.7; s.d.: 1.1) attended a weight-management camp, where HRV was recorded. Stop signal reaction time (SSRT) was also recorded as a measure of impulse control. As expected, SSRT was positively associated with pre-intervention body mass (r=0.301, P=0.010) and negatively associated with PNN50 (ß=0.29, P=0.031). Post-intervention body mass change was positively associated with LF/HF (ß=0.34, P=0.037), but was not associated with HF. Lifestyle interventions may have a greater chance of effectively supporting long-term weight-management for children with lower LF/HF; assessing HRV of obese children may be helpful in informing obesity treatment decisions.
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Sistema Nervoso Autônomo/fisiologia , Pressão Sanguínea/fisiologia , Aptidão Cardiorrespiratória/fisiologia , Frequência Cardíaca/fisiologia , Obesidade Infantil/prevenção & controle , Obesidade Infantil/fisiopatologia , Programas de Redução de Peso , Adolescente , Índice de Massa Corporal , Criança , Feminino , Seguimentos , Humanos , Masculino , Obesidade Infantil/complicações , Valor Preditivo dos Testes , Avaliação de Programas e Projetos de Saúde , Catar , Resultado do TratamentoRESUMO
BACKGROUND AND OBJECTIVES: Variation in the existing literature on the psychosocial benefits of weight loss in obese youth results, in part, from methodological limitations and modest weight loss. Accordingly, this research assessed perceived self-competence and low self-esteem during an intensive weight loss programme in a large sample of obese youth and related these to starting weight, gender and weight loss. METHODS: Over 4 years, 303 obese male and female adolescents (body mass index [BMI] 34.3 kg m-2 , BMI standard deviation score 2.99; 14.7 years) attended a residential weight loss camp for a mean duration of 31 d. Outcome variables included dimensional self-esteem (Harter) and weight change over the camp. RESULTS: At the start of camp, obese youth scored highest on social acceptance and lowest on physical appearance and athletic competence. Global self-worth and most domains of self-competence improved significantly over the intervention. The proportion with low global self-worth reduced from 35% to 16%, but there was little change in the proportion reporting high self-competence (23%). Mean weight loss was -5.5 kg (BMI standard deviation scores -0.25) with boys and those heaviest at the start losing most. Weight loss was significantly correlated with improved physical appearance (r = 0.13) and athletic competence (r = 0.19), but not global self-worth. CONCLUSIONS: This intensive weight loss intervention yielded significant psychological benefit, especially in self-competence and among individuals achieving most weight loss. The weak association with weight loss suggests the influence of other contributing environmental or social features that should be the focus of further research.
Assuntos
Obesidade Infantil/psicologia , Autoimagem , Programas de Redução de Peso/métodos , Adolescente , Índice de Massa Corporal , Peso Corporal , Feminino , Humanos , Masculino , Obesidade Infantil/terapia , Redução de PesoRESUMO
BACKGROUND/OBJECTIVES: According to the COM-B ('Capability', 'Opportunity', 'Motivation' and 'Behaviour') model of behaviour, three factors are essential for behaviour to occur: capability, opportunity and motivation. Obese children are less likely to feel capable of exercising. The implementation of a new methodological approach to investigate the relationship between perceived exercise capability (PEC) and childhood obesity was conducted, which involved creating a new instrument, and demonstrating how it can be used to measure obesity intervention outcomes. SUBJECTS/METHODS: A questionnaire aiming to measure perceived exercise capability, opportunity and motivation was systematically constructed using the COM-B model and administered to 71 obese children (aged 9-17 years (12.24±0.2.01), body mass index (BMI) standard deviation scores (SDS) 2.80±0.660) at a weight-management camp in northern England. Scale validity and reliability was assessed. Relationships between PEC, as measured by the questionnaire, and BMI SDS were investigated for the children at the weight-management camp, and for 45 Spanish schoolchildren (aged 9-13 years, (10.52±1.23), BMI SDS 0.80±0.99). A pilot study, demonstrating how the questionnaire can be used to measure the effectiveness of an intervention aiming to bring about improved PEC for weight-management camp attendees, was conducted. No participants withdrew from these studies. RESULTS: The questionnaire domain (exercise capability, opportunity and motivation) composite scales were found to have adequate internal consistency (a=0.712-0.796) and construct validity (χ(2)/degrees of freedom=1.55, root mean square error of approximation=0.072, comparative fit index=0.92). Linear regression revealed that low PEC was associated with higher baseline BMI SDS for both UK (b=-0.289, P=0.010) and Spanish (b=-0.446, P=0.047) participants. Pilot study findings provide preliminary evidence for PEC improvements through intervention being achievable, and measurable using the questionnaire. CONCLUSIONS: Evidence is presented for reliability and validity of the questionnaire, and for feasibility of its use in the context of a childhood obesity intervention. Future research could investigate the link between PEC and childhood obesity further.
Assuntos
Tolerância ao Exercício/fisiologia , Exercício Físico/psicologia , Obesidade Infantil/psicologia , Programas de Redução de Peso , Adolescente , Criança , Inglaterra/epidemiologia , Estudos de Viabilidade , Feminino , Humanos , Masculino , Motivação , Obesidade Infantil/epidemiologia , Obesidade Infantil/prevenção & controle , Projetos Piloto , Reprodutibilidade dos Testes , Autoimagem , Espanha/epidemiologia , Inquéritos e QuestionáriosAssuntos
Adiposidade , Obesidade/epidemiologia , Pobreza/estatística & dados numéricos , Feminino , Humanos , MasculinoRESUMO
OBJECTIVE: Small, dense low-density lipoprotein (LDL) particles are highly atherogenic and strongly associated with obesity-related dyslipidemia. The metabolic inter-relationships between weight loss induced changes in waist circumference, triglycerides, insulin sensitivity and small-dense LDL particles in clinically obese children and adolescents have not been studied. METHODS: Seventy-five clinically obese boys and girls (standardized body mass index 3.07 ± 0.59, aged 8-18 years) were recruited. Anthropometric, body composition and cardiometabolic risk factors were measured pre- and post-weight loss. RESULTS: There were highly significant reductions in anthropometric, body composition and cardiometabolic risk factors. Triglyceride change was positively correlated with LDL peak particle density and percentage LDL pattern B changes (relative abundance of small, dense LDL particles). Multiple regression analyses showed that changes in triglyceride concentration accounted for between 24 and 18% of the variance in LDL peak particle density and percentage LDL pattern B change, respectively. Changes in waist circumference and insulin sensitivity did not predict these changes in LDL characteristics. CONCLUSION: Acute and highly significant weight loss significantly decreased LDL peak particle density and percentage LDL pattern B. The change in triglycerides was a strong predictor of LDL peak particle density and percentage LDL pattern B change.
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Dislipidemias/metabolismo , Resistência à Insulina , Lipoproteínas LDL/metabolismo , Obesidade Infantil/metabolismo , Triglicerídeos/metabolismo , Circunferência da Cintura , Adolescente , Índice de Massa Corporal , Restrição Calórica , Criança , Dislipidemias/epidemiologia , Dislipidemias/prevenção & controle , Feminino , Educação em Saúde , Humanos , Masculino , Obesidade Infantil/epidemiologia , Obesidade Infantil/prevenção & controle , Projetos Piloto , Redução de PesoRESUMO
BACKGROUND: Obese individuals are known to be more impulsive than their normal-weight counterparts. Impulsivity has been postulated to be a predictor of weight loss. DESIGN: A pre-post study was designed to determine for the first time whether impulsivity changed with weight loss during a lifestyle and physical activity intervention programme lasting 2-8 weeks. SUBJECTS: Fifty-three obese adolescents with a body mass index (BMI) of 33.75 ± 7.9 attending a residential camp were tested and compared at baseline with 50 non-obese adolescents with a mean BMI of 20.6 ± 2.3. MEASUREMENTS: Inhibitory control was measured with the CANTAB (Cambridge Cognition, Cambridge, UK) Stop Signal Task. MATLAB (The Mathswork Inc., Natick, MA, USA) was used to measure the temporal discounting constant. RESULTS: The obese group was more impulsive than the normal weight adolescents. BMI reduced significantly from 33.76 kg m(-2) to 30.93 kg m(-2) after completing camp. The stop signal reaction time (SSRT) decreased from 225.38 ± 94.22 to 173.76 ± 107.05 ms (n=47, P=0.0001). A reduction in inhibitory control during camp was predictive of those who showed the greatest reduction in BMI (Wilks' Lambda=0.9, F(1,50)=4.85, P=0.034). The number of weeks in camp (Wilks' Lambda=0.83, F(1,50)=9.826, P=0.003) and the age of the adolescents (Wilks' Lambda=0.87, F(1,50)=5.98, P=0.02) were significantly associated with a reduction in inhibitory control as measured by the SSRT. A longer stay in camp was associated with a greater reduction in SSRT (B=25.45, t=2.02, P=0.05). Increasing age had a significant moderating role in the reduction of inhibitory control (B=-0.3, t=-0.034, P=0.05). Temporal discounting for monetary reward also fell significantly during camp. CONCLUSION: This study highlights the potential to identify those who are obese by using an easy-to-measure psychometric test. Furthermore, it is the first study to report a reduction in impulsivity and an improvement in well-being as part of a government-approved residential camp for obese adolescents. The potential mechanisms for change in impulsivity with weight are discussed.
Assuntos
Comportamento do Adolescente/psicologia , Terapia Comportamental , Comportamento Impulsivo , Obesidade Infantil/psicologia , Obesidade Infantil/terapia , Redução de Peso , Adolescente , Índice de Massa Corporal , Criança , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Obesidade Infantil/complicações , Obesidade Infantil/fisiopatologia , Valor Preditivo dos Testes , Recompensa , Comportamento de Redução do RiscoRESUMO
OBJECTIVE: The purpose of this study was to examine the prevalence of obesity over time in the same individuals comparing body mass index (BMI), waist circumference (WC) and waist to height ratio (WHtR). STUDY DESIGN: Five year longitudinal repeated measures study (2005-2010). Children were aged 11-12 (Y7) years at baseline and measurements were repeated at age 13-14 (Y9) years and 15-16 (Y11) years. METHODS: WC and BMI measurements were carried out by the same person over the five years and raw values were expressed as standard deviation scores (sBMI and sWC) against the growth reference used for British children. RESULTS: Mean sWC measurements were higher than mean sBMI measurements for both sexes and at all assessment occasions and sWC measurements were consistently high in girls compared to boys. Y7 sWC = 0.792 [95% confidence interval (CI) 0.675-0.908], Y9 sWC = 0.818 (95%CI 0.709-0.928), Y11 sWC = 0.943 (95%CI 0.827-1.06) for boys; Y7 sWC = 0.843 (0.697-0.989), Y9 sWC = 1.52 (95%CI 1.38-0.67), Y11 sWC = 1.89 (95%CI 1.79-2.04) for girls. Y7 sBMI = 0.445 (95%CI 0.315-0.575), Y9 sBMI = 0.314 (95%CI 0.189-0.438), Y11 sBMI = 0.196 (95%CI 0.054-0.337) for boys; Y7 sBMI = 0.353 (0.227-0.479), Y9 sBMI = 0.343 (95%CI 0.208-0.478), Y11 sBMI = 0.256 (95%CI 0.102-0.409) for girls. The estimated prevalence of obesity defined by BMI decreased in boys (18%, 12% and 10% in Y 7, 9 and 11 respectively) and girls (14%, 15% and 11% in Y 7, 9 and 11). In contrast, the prevalence estimated by WC increased sharply (boys; 13%, 19% and 23%; girls, 20%, 46% and 60%). CONCLUSION: Central adiposity, measured by WC is increasing alongside a stabilization in BMI. Children appear to be getting fatter and the additional adiposity is being stored centrally which is not detected by BMI. These substantial increases in WC are a serious concern, especially in girls.
Assuntos
Índice de Massa Corporal , Obesidade Infantil/epidemiologia , Circunferência da Cintura , Adolescente , Estatura , Criança , Feminino , Humanos , Estudos Longitudinais , Masculino , PrevalênciaRESUMO
OBJECTIVE: It has been suggested that childhood obesity is inversely associated with deprivation, such that the prevalence is higher in more deprived groups. However, comparatively few studies actually use an area-level measure of deprivation, limiting the scope to assess trends in the association with obesity for this indicator. Furthermore, most assume a linear relationship. Therefore, the aim of this study was to investigate associations between area-level deprivation and three measures of adiposity in children: body mass index (BMI), waist circumference (WC) and waist-to-height ratio (WHtR). DESIGN: This is a cross-sectional study in which data were collected on three occasions a year apart (2005-2007). SUBJECTS: Data were available for 13,333 children, typically aged 11-12 years, from 37 schools and 542 lower super-output areas (LSOAs). MEASURES: Stature, mass and WC. Obesity was defined as a BMI and WC exceeding the 95th centile according to British reference data. WHtR exceeding 0.5 defined obesity. The Index of Multiple Deprivation affecting children (IDACI) was used to determine area-level deprivation. RESULTS: Considerable differences in the prevalence of obesity exist between the three different measures. However, for all measures of adiposity the highest probability of being classified as obese is in the middle of the IDACI range. This relationship is more marked in girls, such that the probability of being obese for girls living in areas at the two extremes of deprivation is around half that at the peak, occurring in the middle. CONCLUSION: These data confirm the high prevalence of obesity in children and suggest that the relationship between obesity and residential area-level deprivation is not linear. This is contrary to the 'deprivation theory' and questions the current understanding and interpretation of the relationship between obesity and deprivation in children. These results could help make informed decisions at the local level.
Assuntos
Adiposidade , Obesidade/epidemiologia , Pobreza/estatística & dados numéricos , Índice de Massa Corporal , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Cadeias de Markov , Obesidade/etiologia , Obesidade/prevenção & controle , Prevalência , Distribuição por Sexo , Reino Unido/epidemiologiaRESUMO
OBJECTIVES: To examine the validity of body composition estimates obtained using foot-to-foot bio-electrical impedance analysis (BIA) in overweight and obese children by comparison to a reference four-compartment model (4-CM). SUBJECTS/METHODS: 38 males: age (mean +/- sd) 13.6 +/- 1.3 years, body mass index 30.3 +/- 6.0 kg.m(-2) and 14 females: age 14.7 +/- 2.2 years, body mass index 32.4 +/- 5.7 kg.m(-2) participated in the study. Estimates of fat-free mass (FFM), fat mass (FM) and percentage body fat (PBF) obtained using a Tanita model TBF-310 and a 4-CM (derived from body mass, body volume, total body water and total body bone mineral measurements) were compared using bias and 95% limits of agreement (Tanita minus 4-CM estimates). RESULTS: Body composition estimates obtained with the Tanita TBF-310 were not significantly different from 4-CM assessments: for all subjects combined the bias was -0.7kg for FM, 0.7kg for FFM and -1.3% for PBF. However, the 95% limits of agreement were substantial for individual children: males, up to +/-9.3kg for FFM and FM and +/-11.0% for PBF; females, up to +/-5.5kg for FFM and FM and +/-6.5% for PBF. CONCLUSIONS: The Tanita TBF-310 foot-to-foot BIA body composition analyser with the manufacturer's prediction equations is not recommended for application to individual children who are overweight and obese although it may be of use for obtaining group mean values.
RESUMO
The aim of this study was to ascertain whether health care professionals are able to accurately identify overweight and obese children by observation alone. Eighty health care professionals were asked to view photographs of 33 children and assign each into one of six categories, ranging from "very underweight" to "obese". The health care professionals' categorisation was compared with the children's degree of adiposity based on conventional clinical criteria for BMI. The health care professionals were found to be generally poor at assessing the weight status of the children, and in particular tended to underestimate overweight and obesity in children. This study suggests that it is not appropriate to rely on informal assessment to identify obesity and highlights the need for health care professionals to be aware of their lack of accuracy in this regard.
Assuntos
Obesidade/diagnóstico , Observação , Adolescente , Composição Corporal/fisiologia , Criança , Feminino , Inquéritos Epidemiológicos , Humanos , Masculino , Obesidade/complicações , Sobrepeso/diagnóstico , Fotografação , Magreza/diagnósticoRESUMO
OBJECTIVE: To assess the subjective appetite responses to an imposed activity- and diet-induced energy deficit during a residential intervention programme for obese children. DESIGN: A 6-week intervention of fixed, reduced dietary intake and 6 h/day of skill-based physical activity while resident in a weight loss camp. SUBJECTS: Thirty-eight obese (mean body mass index (BMI)=34.9 kg m(-2)) boys and girls (mean age 13.9+/-1.57). MEASUREMENTS: An electronic appetite rating system (EARS) was used to periodically measure subjective appetite sensations at the start (WK1) and at the end (WK6) of the camp. Subjective ratings of hunger and fullness were compared at the start and end of 6 weeks of an activity- and diet-induced-based weight loss intervention. RESULTS: At the end of the 6 weeks, the children had lost 8.4 kg in body mass. The diurnal profiles of subjective appetite sensations demonstrated clear oscillations in hunger and fullness. There was a significant increase in hunger (P<0.0001) and decrease in fullness (P<0.005) at the end (WK6) of the medium-term energy deficit. In WK6, morning ratings of hunger were higher than in WK1 (P<0.005) and the fixed energy evening meal induced a lower suppression of hunger (P<0.02). CONCLUSION: A programme of fixed, reduced-dietary intake combined with an activity and behavioural programme was successful at inducing a significant reduction in body mass in obese children. Subjective sensations of appetite were sensitive to a medium-term negative energy balance and weight loss. These data are essential as we continue to evolve methods of treatment for overweight and obese children.
Assuntos
Apetite , Dieta Redutora , Ingestão de Energia , Atividade Motora , Obesidade/terapia , Adolescente , Índice de Massa Corporal , Criança , Ritmo Circadiano , Terapia Combinada , Feminino , Educação em Saúde , Humanos , Fome , Masculino , Obesidade/dietoterapia , Obesidade/psicologia , Sensação , Resultado do Tratamento , Redução de PesoRESUMO
BACKGROUND AND AIM: Residential camps have been used to deliver weight-loss interventions to paediatric populations, but very little is known about how children perceive and evaluate attending such camps. Therefore, this study examined children's perceptions of attending a residential paediatric weight-loss camp. METHODS: Fifteen attendees (mean age = 13.56) of the 2002 Carnegie International Camp-UK (CIC-UK) were engaged in semi-structured interviews, which were transcribed verbatim and subjected to an inductive analysis procedure. RESULTS: Results reflected pre-camp issues including worries (boot camp fears, being bullied) and goals and aspirations (weight loss goals, reducing bullying, increasing self-esteem and making friends). Negative elements pertaining to the camp experience were homesickness and dietary concerns. Positive elements of the camp experience were enjoyment, peer support, staff support and choice of activities. CONCLUSION: Enjoyment, support from peers and staff and choice over activities appear to be important aspects in the delivery of residential obesity treatments for children.
Assuntos
Serviços de Saúde da Criança/organização & administração , Obesidade/terapia , Satisfação do Paciente , Redução de Peso , Adolescente , Atitude Frente a Saúde , Criança , Comportamento Infantil , Dieta/psicologia , Terapia por Exercício , Feminino , Objetivos , Humanos , Relações Interpessoais , Masculino , Psicologia da Criança , Apoio Social , Reino UnidoRESUMO
OBJECTIVE: To evaluate the accuracy of percentage body fat (%fat) estimates from air displacement plethysmography (ADP) against an increasingly recognised criterion method, dual-energy X-ray absorptiometry (DXA), in young adolescents. DESIGN: Cross-sectional evaluation. SETTING: Leeds General Infirmary, Centre for Bone and Body Composition Research, Leeds, UK. SUBJECTS: In all, 28 adolescents (12 males and 16 females), age (mean+/-s.d.) 14.9+/-0.5 y, body mass index 21.2+/-2.9 kg/m(2) and body fat (DXA) 24.2+/-10.2% were assessed. RESULTS: ADP estimates of %fat were highly correlated with those of DXA in both male and female subjects (r=0.84-0.95, all P<0.001; s.e.e.=3.42-3.89%). Mean %fat estimated by ADP using the Siri (1961) equation (ADP(Siri)) produced a nonsignificant overestimation in males (0.67%), and a nonsignificant underestimation in females (1.26%). Mean %fat estimated by ADP using the Lohman (1986) equations (ADP(Loh)) produced a nonsignificant underestimation in males (0.90%) and a significant underestimation in females (3.29%; P<0.01). Agreement between ADP and DXA methods was examined using the total error (TE) and methods of Bland and Altman (1986). Males produced a smaller TE (ADP(Siri) 3.28%; ADP(Loh) 3.49%) than females (ADP(Siri) 3.81%; ADP(Loh) 4.98%). The 95% limits of agreement were relatively similar for all %fat estimates, ranging from +/-6.57 to +/-7.58%. Residual plot analyses, of the individual differences between ADP and DXA, revealed a significant bias associated with increased %fat (DXA), only in girls (P<0.01). CONCLUSIONS: We conclude that ADP, at present, has unacceptably high limits of agreement compared to a criterion DXA measure. The ease of use, suitability for various populations and cost of ADP warrant further investigation of this method to establish biological variables that may influence the validity of body fat estimates.
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Absorciometria de Fóton/métodos , Tecido Adiposo/metabolismo , Composição Corporal/fisiologia , Pletismografia/métodos , Adolescente , Ar , Estudos Transversais , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Fatores SexuaisRESUMO
The objective of the present study was to investigate the accuracy of percent body fat (%fat) estimates from dual-energy X-ray absorptiometry, air-displacement plethysmography (ADP), and total body water (TBW) against a criterion four-compartment (4C) model in overweight and obese children. A volunteer sample of 30 children (18 male and 12 female), age of (mean +/- SD) 14.10 +/- 1.83 yr, body mass index of 31.6 +/- 5.5 kg/m, and %fat (4C model) of 41.2 +/- 8.2%, was assessed. Body density measurements were converted to %fat estimates by using the general equation of Siri (ADPSiri) (Siri WE. Techniques for Measuring Body Composition. 1961) and the age- and gender-specific constants of Lohman (ADPLoh) (Lohman TG. Exercise and Sport Sciences Reviews. 1986). TBW measurements were converted to %fat estimates by assuming that water accounts for 73% of fat-free mass (TBW73) and by utilizing the age- and gender-specific water contents of Lohman (TBWLoh). All estimates of %fat were highly correlated with those of the 4C model (r > or = 0.95, P < 0.001; SE < or = 2.14). For %fat, the total error and mean difference +/- 95% limits of agreement compared with the 4C model were 2.50, 1.8 +/- 3.5 (ADPSiri); 1.82, -0.04 +/- 3.6 (ADPLoh); 2.86, -2.0 +/- 4.1 (TBW73); 1.90, -0.3 +/- 3.8 (TBWLoh); and 2.74, 1.9 +/- 4.0 DXA (dual-energy X-ray absorptiometry), respectively. In conclusion, in overweight and obese children, ADPLoh and TBWLoh were the most accurate methods of measuring %fat compared with a 4C model. However, all methods under consideration produced similar limits of agreement.
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Absorciometria de Fóton/métodos , Composição Corporal , Obesidade/diagnóstico por imagem , Obesidade/patologia , Pletismografia/métodos , Absorciometria de Fóton/normas , Adolescente , Compartimentos de Líquidos Corporais , Água Corporal , Criança , Feminino , Humanos , Masculino , Pletismografia/normas , Reprodutibilidade dos TestesRESUMO
OBJECTIVES: To investigate the change in body image, self-esteem, and worries in obese adolescents attending a residential, weight-loss camp. DESIGN: A longitudinal intervention study, with a nonintervention comparison group of lean adolescents. PARTICIPANTS: A total of 57 obese adolescents (age: 13,11; BMI: 32.6 kg/m(2)) and 38 normal weight comparison adolescents. MEASURES: Self-esteem, salience of weight-related issues, body shape preference, weight and height at the start, and end of the weight-loss camp (mean stay: 4 weeks). RESULTS: The obese adolescents lost 5.6 kg, reduced their BMI by 2.1 kg/m(2), and BMI s.d. score by 0.28 while comparison children gained weight. Body shape dissatisfaction significantly decreased and self-esteem increased on measures of global self-worth, athletic competence, and physical appearance, in the camp attendees. This improvement took place without any exacerbation of existing worries about appearance or weight. CONCLUSIONS: While obese adolescents had lower self-worth and greater body dissatisfaction relative to the comparison children at the start of the camp, the intervention improved their psychological state. Greater weight loss was associated with greater psychological improvement, indicating the value of the intervention and the relevance of psychological change in effective treatment.
Assuntos
Comportamento do Adolescente/psicologia , Comportamentos Relacionados com a Saúde , Estâncias para Tratamento de Saúde , Obesidade/psicologia , Redução de Peso , Adolescente , Atitude Frente a Saúde , Imagem Corporal , Índice de Massa Corporal , Criança , Feminino , Humanos , Estudos Longitudinais , Masculino , AutoimagemRESUMO
The association of both leisure-time physical activity and obesity with lipoprotein-lipids and composite atherogenic markers were examined within a cross-sectional study of middle-aged men of higher socioeconomic status. Analyses were performed on a subsample (n=629) of non-smoking, non-diabetic men (46.7+/-7.8 years) who completed a preventive medical assessment between 1992 and 1996. Mean adjusted (age, body mass index (BMI), sum of skinfolds, fasting glucose, and logarithmic alcohol consumption) levels of high-density lipoprotein-cholesterol (HDL-C) were significantly higher, and logarithmic triglycerides significantly lower, with higher physical activity index (PAI) categories (both P<0.0001). Significantly lower adjusted mean ratios of both total cholesterol to HDL-C (TC:HDL-C), and logarithmic triglycerides to HDL-C (TG:HDL-C) with higher PAI were evident following adjustment for the above covariates (P=0.005 and P<0.0001). Age-adjusted non-HDL-C (total cholesterol minus HDL-C) decreased significantly with higher PAI categories, but was not significantly lower following covariate adjustment (P=0.150). On stepwise multiple regression, logarithmic physical activity score and BMI explained 9.5-14% of the variance in the TC:HDL-C and TG:HDL-C ratios in models including age, body mass, sum of skinfolds, fasting glucose and logarithmic alcohol consumption. Age, sum of skinfolds and logarithmic alcohol consumption were significant predictors of non-HDL-C (r2=8.0%). These findings emphasise the importance of both physical activity and obesity in predicting lipoprotein-lipid risk markers.