Global prevalence and gender inequalities in at least 60 min of self-reported moderate-to-vigorous physical activity 1 or more days per week: An analysis with 707,616 adolescents.

BACKGROUND: Guidelines recommend that adolescents should accumulate an average of 60 min per day of moderate-to-vigorous physical activity (MVPA). However, using only this cut-off could hide important information. For instance, from a population-level point of view, increasing physical activity for those with no or low physical activity could provide more health benefits than increasing physical activity for those with intermediate levels. Also, including a more sensitive cut-point of ≥1 day per week could be an additional strategy for identifying those with low access/opportunities for physical activity practice. Thus, the current study aims to estimate the prevalence of ≥60 min of MVPA ≥1 days per week among adolescents globally, and to describe any relevant gender inequalities. METHODS: We used representative datasets from 146 countries/territories collected between 2003 and 2019. MVPA was self-reported. Participants were grouped into younger (≤14 years old) and older (>14 years old) adolescents. Crude Poisson regression models were used to identify the relative differences in ≥60 min of MVPA ≥1 days per week between boys and girls, and random-effects meta-analysis models were used to identify the pooled estimates. Analyses were stratified by country and region. RESULTS: Approximately 80% of both younger and older adolescents reported ≥60 min of MVPA ≥1 days per week. This prevalence was ≥94% in Europe and Central Asia and North America, while the estimates for the other regions were <77%. The prevalence of ≥60 min of MVPA ≥1 days per week was higher among boys than girls, with the largest differences occurring among the oldest adolescents (PR≤14y: 1.04 (95% confidence interval (95%CI): 1.03‒1.04) vs. PR>14y: 1.09 (95%CI: 1.08‒1.10)). CONCLUSION: Approximately 8 out of 10 adolescents reported accumulating ≥60 min of MVPA ≥1 day per week, with notable differences between regions. Gender differences were observed in several countries, especially among the oldest adolescents. Priorities for physical activity promotion among adolescents should include increasing access/opportunities for physical activity among those who do not achieve ≥60 min of MVPA ≥1 days per week and reducing gender inequalities.

Physical activity can attenuate, but not eliminate, the negative relationships of high TV viewing with some chronic diseases: findings from a cohort of 60 202 Brazilian adults.

BACKGROUND: This study examined the joint associations of leisure time physical activity and television (TV) viewing time with the prevalence of chronic diseases among Brazilian adults. METHODS: Data from the Brazilian Health Survey, a nationally representative survey conducted in 2013 (n = 60 202; ≥18 years), were used. Time spent in TV viewing and leisure physical activity, physician diagnoses of diabetes, hypertension and heart disease and information on co-variables (chronological age, education, ethnicity, candies/sweets consumption, sodium intake and tobacco smoking) were collected via interview. Descriptive statistics (mean and 95% confidence interval) and logistic regression models were used for etiological analyses. RESULTS: Physical activity attenuated but did not eliminate the risk associated with high TV viewing for at least one chronic disease in the general population [odds ratio [OR]: 1.29 (1.11-1.50)] and among women [OR: 1.31 (1.09-1.60)], adults [OR: 1.24 (1.05-1.46)] and older adults [OR: 1.63 (1.05-2.53)]. On the other hand, physical activity eliminated the risk associated with high TV viewing for at least one chronic disease among men [OR: 1.24 (0.98-1.58)]. CONCLUSIONS: We conclude that physical activity can attenuate but not eliminate the negative effects of high TV viewing on chronic disease among subgroups of Brazilian adults.

How may the reduction of some cardiovascular diseases affect Brazilian population's life expectancy? / Como a redução de algumas doenças cardiovasculares pode afetar a expectativa de vida da população brasileira? / ¿Cómo puede afectar la reducción de algunas enfermedades cardiovasculares la esperanza de vida de la población brasileña?

This study aimed to analyze the impact of cardiovascular diseases (CVDs) on life expectancy (LE) in the Brazilian population; and to identify how the hypothetical reduction in mortality from 5 to 30%, as well as the hypothetical scenario with no deaths (i.e., elimination) of these diseases would affect LE. This is a simulation study using national cross-sectional data. To identify the impact of CVDs on LE, we used multiple decrement life table models, considering hypothetical CVDs reductions in mortality from 5 to 30% and their elimination. The estimated overall potential gains in LE [years (%)] from the elimination of ischemic disease, hypertensive disease, and cerebrovascular disease were 1.44y (2%) and 1.31y (1.7%), 0.51y (0.7%) and 0.75y (1%), and 1.28y (1.8%) and 1.62y (2.1%), for males and females, respectively. The largest gains in LE were observed among those who live in Brazil's Northeast region. For the overall population, the estimated gains in LE linked to a 5% reduction in CVD mortality for males and females were 0.07y (0.1%) and 0.06y (0.08%) for ischemic disease, 0.02y (0.03%) and 0.04y (0.05%) for hypertensive disease, and 0.06y (0.08%) and 0.07y (0.09%) for cerebrovascular disease. A hypothetical decrease of 30% in mortality by CVDs would lead to gains in LE, for males and females, of 0.41y (0.6%) and 0.37y (0.5%) for ischemic disease, 0.15y (0.2%) and 0.22y (0.3%) for hypertensive disease, and 0.36y (0.5%) and 0.45y (0.6%) for cerebrovascular disease. Thus, investment towards improving CVDs, including CVD prevention efforts, would increase LE in Brazil, especially in less developed regions.

O presente estudo objetiva analisar o impacto das doenças cardiovasculares (DCV) na expectativa de vida (EV) da população brasileira e identificar como a EV seria afetada pela redução hipotética de 5% a 30% e pela eliminação da mortalidade por essas doenças. Trata-se de um estudo de simulação que utiliza dados transversais a nível nacional. A análise foi realizada por meio do modelo de tábuas de vida de múltiplo decremento, considerando reduções na mortalidade por DCV de 5% a 30%, assim como a sua eliminação. Os ganhos potenciais estimados na EV, em anos e porcentagem, por meio da eliminação das doenças isquêmica, hipertensiva e cerebrovascular foram de, respectivamente, para homens e mulheres, 1,44 (2%) e 1,31 (1,7%), 0,51 (0,7%) e 0,75 (1%), 1,28 (1,8%) e 1,62 (2,1%). Os maiores ganhos ocorrem entre os residentes na região Nordeste. Além disso, para a população em geral, os ganhos estimados em EV a partir de uma redução de 5% na mortalidade por DCV, em homens e mulheres, foram de 0,07 (0,1%) e 0,06 (0,08%), para doença isquêmica, 0,02 (0,03%) e 0,04 (0,05%), para doença hipertensiva, e 0,06 (0,08%) e 0,07 (0,09%), para doença cerebrovascular. Já uma redução hipotética de 30% na mortalidade por DCV foi acompanhada de ganhos na EV, para homens e mulheres, de 0,41 (0,6%) e 0,37 (0,5%), para doença isquêmica, 0,15 (0,2%) e 0,22 (0,3%), para doença hipertensiva, e 0,36 (0,5%) e 0,45 (0,6%), para doença cerebrovascular. Assim, mais investimentos e esforços orientados para a prevenção de DCV aumentariam a EV no Brasil, principalmente nas regiões menos desenvolvidas.

Los objetivos de este estudio fueron analizar el impacto de las enfermedades cardiovasculares (ECV) en la esperanza de vida (EV) de la población brasileña e identificar cuánto afectarían a la EV una hipotética reducción del 5 al 30% o la eliminación de la mortalidad por estas enfermedades. Este es un estudio de simulación que utiliza datos transversales nacionales. El análisis de datos se hizo utilizando modelos de tablas de vida de múltiples decrementos, considerando reducciones en la mortalidad por ECV del 5% al 30% así como su eliminación. Las ganancias potenciales estimadas para la EV [años (%)] vinculadas a la eliminación de la enfermedad isquémica, enfermedad hipertensiva, y la enfermedad cerebrovascular fueron 1,44 (2%) y 1,31 (1,7%), 0,51 (0,7%) y 0,75 (1%), y 1,28 (1,8%) y 1,62 (2,1%), para varones y mujeres, respectivamente. Las mayores ganancias en la EV fueron observadas en la población de la región noreste de Brasil. Las ganancias estimadas en EV ligadas a una reducción del 5% en la mortalidad por ECV en hombres y mujeres fueron 0,07 (0,1%) y 0,06 (0,08%) para enfermedad isquémica, 0,02 (0,03%) y 0,04 (0,05%) para enfermedad hipertensiva, y 0,06 (0,08%) y 0,07 (0,09%) para enfermedad cerebrovascular. Una disminución hipotética del 30% en la mortalidad por ECV se acompañaría de ganancias en EV, para hombres y mujeres, de 0,41 (0,6%) y 0,37 (0,5%) para enfermedad isquémica, 0,15 (0,2%) y 0,22 (0,3%) para enfermedad hipertensiva, y 0,36 (0,5%) y 0,45 (0,6%) para enfermedad cerebrovascular. Esfuerzos orientados a la prevención de las ECV aumentarían la EV en Brasil, especialmente en las regiones menos desarrolladas.

Total and regional bone mineral density are associated with cellular health in older men and women.

OBJECTIVE: This study aimed to investigate the relationship between crude bioimpedance variables with bone mineral density (BMD) in older adults. METHOD: One hundred eighty-four older men and women (≥ 60 years old) composed the sample. BMD (whole-body) was measured through dual-energy X-ray absorptiometry. Bioimpedance spectroscopy was used to estimate whole-body resistance and reactance as well as to calculate the phase angle (PhA) and fat-free mass (FFM). Age, gender, body mass, FFM, height, calcium intake, vitamin D intake, number of fractures, number of diseases, and number of medications were included as covariates in the regression analyses. RESULTS: BMD fractions were significantly (P < 0.01) associated with PhA (femur: r = 0.524; neck: r = 0.450; and forearm: r = 0.437). Independently of age, body mass, FFM, calcium intake, vitamin D, number of diseases, fratures and medications, PhA remains a significant explanator of the variability of total (ß = 0.22; P < 0.001), femur (ß = 0.10; P = 0.018), and neck BMD (ß = 0.07; P = 0.05) for men, and total (ß = 0.08; P = 0.002), femur (ß = 0.06; P = 0.005), neck (ß = 0.04; P = 0.03), and forearm BMD (ß = 0.05; P = 0.004) for women. CONCLUSION: Our results suggest that a higher PhA is associated with BMD in older men and women fractions regardless of relevant covariates highlighting the biological meaning of this simple and crude bioimpedance-based measure in the elderly population.

Agreement Between Bioelectrical Impedance and Dual-Energy X-Ray Absorptiometry to Track Changes in Fat-Free Mass After Resistance Training in Older Women.

Nascimento, MA, Silva, DRP, Ribeiro, AS, Pina, FLC, Gerage, AM, Gobbo, LA, Mayhew, JL, and Cyrino, ES. Agreement between bioelectrical impedance and dual-energy x-ray absorptiometry to track changes in fat-free mass after resistance training in older women. J Strength Cond Res 34(6): 1700-1708, 2020-The aim of our study was to compare the agreement between bioelectrical impedance (BIA) and dual-energy X-ray absorptiometry (DXA) to track changes on fat-free mass (FFM) after a resistance training (RT) program in older women. Forty-three older women (65.2 ± 4.6 years, 59.5 ± 9.2 kg, 156.4 ± 6.0 cm, 24.3 ± 3.3 kg·m) participated in a RT intervention (12 weeks, 8 exercises, 2 sets, 10-15 repetitions, 3 nonconsecutive days per week). Fat-free mass changes were determined by a single-frequency BIA device (EQ1), 6 BIA prediction equations for older women (EQ2, EQ3, EQ4, EQ5, EQ6, and EQ7), and DXA. At pretraining, 3 equations overpredicted, and 3 underpredicted DXA FFM (F = 244.63, p < 0.001), although all equations had high correlations with DXA (r = 0.78-0.83). After training, 4 equations overpredicted and one underpredicted DXA FFM (F = 176.25, p < 0.001). Dual-energy X-ray absorptiometry detected significant gains in FFM (0.65 ± 0.82 kg; p < 0.05), as did EQ3 (0.55 ± 1.69 kg; p < 0.05), and EQ4 (0.61 ± 1.88 kg; p < 0.05), whereas the remaining equations did not indicate significant changes in FFM. Low correlations between FFM and equation change values suggest that single-frequency BIA-derived equations may not provide sufficient accuracy to track changes in FFM after 12 weeks of RT in older women.

Effects of Different Resistance Training Frequencies on Fat in Overweight/Obese Older Women.

AIM: This study compared the effect of different resistance training (RT) frequencies on total, android, gynoid and trunk body fat in overweight/obese older women. METHODS: Fifty-seven overweight/obese older women (66.9±5.3 years and 39.9±4.9% body fat) were randomly assigned to one of three groups: a group performing RT twice a week (G2X), a group performing RT three times a week (G3X), or a non-exercise control group (CG). Both training groups performed the same 12-week RT program consisting of 8 exercises that trained all major muscle groups. Dual-energy X-ray absorptiometry was used to assess body composition. RESULTS: After the intervention period, both G2X and G3X demonstrated significant (P<0.05) reductions in adiposity compared to the CG for total body fat (G2X=-1.7%, G3X=-2.7%, CG=+2.1%), android fat (G2X=-6.2%, G3X=-7.0%, CG=+8.6%), gynoid fat (G2X=-2.5%, G3X=-2.9%, CG=+1.0%), and trunk fat (G2X=-2.5%, G3X=-3.0%, CG=+2.9%), with no significant differences between training groups. CONCLUSION: These results demonstrate that a low-volume 12-week RT program performed two or three times per week causes decreases in total and regional fat deposition with the greatest reductions occurring in the android region.

Physical Activity and Sitting Time Are Specifically Associated With Multiple Chronic Diseases and Medicine Intake in Brazilian Older Adults.

The purpose of the study was to clarify the independent association between sedentary behavior and physical activity with multiple chronic diseases and medicine intake in older individuals. Sedentary behavior and physical activity were measured by questionnaires. Diseases and medication use were self-reported. Poisson's regression was adopted for main analysis, through crude and adjusted prevalence ratio and confidence interval of 95%. For men, sedentary time >4 hr/day presented a 76% higher prevalence of ≥2 chronic diseases, while physical inactivity increases the likelihood of using ≥2 medicines in 95%. For women, sedentary behavior >4 hr/day presented an 82% and 43% greater prevalence for ≥2 chronic diseases and the intake of ≥2 medicines, respectively. Sedentary behavior represents an independent associated factor of multiple chronic diseases in older men and women. In addition, inactivity for men and sedentarism for women are associated with the amount of medicine intake.

Cardiovascular and metabolic risk markers are related to parasympathetic indices in pre-pubertal adolescents.

OBJECTIVE: To analyse the relationship between different heart rate variability indices, resting heart rate, and cardiovascular markers in adolescents. METHODS: A cross-sectional study was carried out with information from an ongoing cohort study. The sample was composed of 99 adolescents who complied with the following inclusion criteria: aged between 11 and 14 years; enrolled in a school unit of elementary education; absence of any known diseases; no drug consumption; and a formal consent signed by the parents or legal guardians. Weight, height, heart rate variability, lipid profile, inflammatory markers, blood pressure, resting heart rate, intima-media thickness, blood flow, and trunk fatness were measured. Partial correlation and linear regression (expressed by ß and 95% confidence intervals [95%CI]) analyses were used to analyse the relationships between the variables. RESULTS: In the linear regression analysis, even after adjustments for sex, age, trunk fatness, and somatic maturation, parasympathetic activity presented significant correlations with maximum carotid artery blood flow (ß=-0.111 [95%CI=-0.216; -0.007]), systolic blood pressure (ß=-0.319 [95%CI=-0.638; -0.001]), and resting heat rate (ß=-0.005 [95%CI=-0.009; -0.002]). CONCLUSION: Parasympathetic activity at rest is inversely related to maximum and minimum blood flow, triacylglycerol levels, and systolic blood pressure. These findings suggest that heart rate variability has the potential to discriminate pre-pubertal adolescents at increased risk.

Correlates of Blood Pressure According to Early, On Time, and Late Maturation in Adolescents.

The aim of this study was to estimate the prevalence and correlates of blood pressure (BP) according to somatic maturation in Southern Brazilian adolescents. A total of 1321 adolescents participated in the study (732 girls), aged between 10 and 16 years, enrolled in public schools. The assessment of BP was performed using oscillometric equipment. Measurements of body weight, height, waist circumference, and skinfold thickness were performed. Somatic maturation was estimated by the age at peak height velocity. Behavioral and hereditary variables were obtained using a questionnaire. Early-maturing adolescents had the highest prevalence of high BP (28%; 95% confidence interval, 24.6-33.5) compared with other maturational groups (P=.003). In late-maturing adolescents, the variables associated with BP were paternal hypertension (systolic BP: ß=4.9; diastolic BP: ß=5.3) and early physical activity (systolic BP: ß=-4.0; diastolic DBP: ß=-3.6). In average-maturing adolescents, waist circumference (systolic BP: ß=0.3), body mass index (diastolic BP: ß=0.5), and mother's hypertension (diastolic BP: ß=1.8) were positively related to BP. In early-maturing adolescents, only waist circumference (systolic BP: ß=0.3; diastolic BP: ß=0.3) was associated with BP. The authors conclude that the prevalence of high BP is greater in adolescents with early maturity and the outcome appears to be related to biological indicators in this group. On the other hand, in late-maturing adolescents, behavioral and hereditary variables are more related to BP.

Correlates of sports practice, occupational and leisure-time physical activity in Brazilian adolescents.

OBJECTIVES: To analyze the relationship between different physical activity (PA) domains and sociodemographic, psychological, behavioral and biological factors in Brazilian adolescents. METHODS: 1,220 adolescents (55.1% female) aged between 10 and 16 years-old participated in this study. The Baecke questionnaire was used to evaluate different PA domains, namely occupational, sports and leisure-time. Socioeconomic status, number of siblings, friendships satisfaction, mother's and father's PA level and previous experience with sports were self-reported. Cardiorespiratory fitness, waist circumference, and somatic maturity were estimated by objective indicators. Linear regression was used for the main statistical analysis. RESULTS: The variables consistently related to all of the PA domains were gender (boys more active), friendship satisfaction (positive with sports and leisure-time PA and negative with occupational PA) and cardiorespiratory fitness (positive). There were also domain-specific relationships for occupational (number of siblings [ß = 0.02] and father's PA [ß = 0.13]), sport practice (previous experience with sports [ß = 0.33], waist circumference [ß = 0.01] and somatic maturity [ß = -0.12]) and leisure-time PA (chronological age [ß = -0.15], mother's PA [ß = 0.47] and previous experience with sports [ß = 0.17]). CONCLUSIONS: The different domains of PA are related to specific variables in adolescence. This information may be helpful in formulating strategies for physical activity promotion, particularly in adolescents from low-to-middle income countries.

Effect of Two- Versus Three-Way Split Resistance Training Routines on Body Composition and Muscular Strength in Bodybuilders: A Pilot Study.

The purpose of this study was to compare different split resistance training routines on body composition and muscular strength in elite bodybuilders. Ten male bodybuilders (26.7 ± 2.7 years, 85.3 ± 10.4 kg) were randomly assigned into one of two resistance training groups: 4 and 6 times per week (G4× and G6×, respectively), in which the individuals trained for 4 weeks, 4 sets for each exercise performing 6-12 repetitions maximum (RM) in a pyramid fashion. Body composition was assessed by dual energy X-ray absorptiometry, muscle strength was evaluated by 1RM bench-press testing. The food intake was planned by nutritionists and offered individually throughout the duration of the experiment. Significant increases (p < .05) in fat-free mass (G4× = +4.2%, G6× = +3.5%) and muscular strength (G4× = +8.4%, G6× = +11.4%) with no group by time interaction were observed. We conclude that 4 and 6 weekly sessions frequencies of resistance training promote similar increases in fat-free mass and muscular strength in elite bodybuilders.

Prevalence of dyslipidemia in adolescents: comparison between definitions.

INTRODUCTION: The indiscriminate use of different diagnostic criteria for the definition of dyslipidemia may result in inaccurate interpretations, which could compromise diagnosis and therefore the therapeutic and prophylactic actions to be taken. OBJECTIVE: To analyze possible differences in prevalence rates of dyslipidemia in adolescents based on three diagnostic definitions. METHODS: A cross-sectional study was conducted of a representative sample of Brazilian adolescents between 11 and 16 years of age. Blood samples were collected from 1000 students (423 boys and 577 girls) to determine fasting total cholesterol (TC), HDL and LDL cholesterol, and triglycerides (TG). The prevalence of dyslipidemia was established according to three definitions: those of the National Cholesterol Education Program (NCEP), the Brazilian Society of Cardiology (BSC), and the National Health and Nutrition Examination Survey (NHANES). RESULTS: Significant differences (p<0.01) were found between the diagnostic criteria for TC (BSC 38.3%; NCEP 11.2%; NHANES 4.8%), HDL cholesterol (BSC 30.0%; NCEP 15.8% NHANES 18.4%), LDL cholesterol (BSC and NCEP 10.8% and NHANES 5.9%), and TG (BSC and NCEP 4.7% and NHANES 1.3%). The overall prevalence of dyslipidemia was 61% (BSC), 28.6% (NCEP) and 24.2% (NHANES). Agreement rates varied significantly (kappa 0.15-0.90). CONCLUSIONS: Although a high prevalence of dyslipidemia was observed in this study regardless of the diagnostic criteria used, the wide variation in rates highlights the need to establish a single definition with appropriate discriminatory power for adolescents.

Static stretching and performance in multiple sets in the bench press exercise.

The purpose of this study was to analyze the acute effect of static stretching on the performance of multiple sets in the bench press (BP) exercise. Fifteen men (26.2 ± 0.7 years, 72.4 ± 1.3 kg, 1.78 ± 0.1 m, 22.8 ± 0.3 kg·m) performed 4 sets of the BP exercise at 80% of 1 repetition maximum until concentric failure, both in the stretching condition (SC) and control condition (CC). The rate of force decline between the first and the fourth set was used as fatigue index. A randomized, counterbalanced, crossover design was performed with 48 hours between each session. Two static stretching exercises (pectoral and triceps brachii muscles) were performed in a single set before BP in SC, whereas in CC, subjects remained at rest for 150 seconds. For each stretching exercise, the muscle was held at the maximal stretched position for 30 seconds. No significant difference (p > 0.05) was identified for total repetitions performed in 4 sets (SC, 21.3 ± 0.7% vs. CC, 20.5 ± 0.7%) and in the fatigue index (SC, 75.5 ± 1.3% vs. CC, 73.2 ± 1.9%). The results suggest that the performance of multiple sets in the BP exercise does not seem to be influenced by previous static stretching.

Validity of the methods to assess body fat in children and adolescents using multi-compartment models as the reference method: a systematic review.

OBJECTIVE: To analyze the validity of methods to assess body fat in children and adolescents using a systematic review. METHODS: The search was conducted by two independent researchers using the MEDLINE, BioMed Central, SciELO and LILACS electronic databases. For inclusion, the articles should be written in English or Portuguese, and must have used multi-compartment models as the criterion measure of the model, with body fat measurement of whole body in non-athlete children and adolescents. RESULTS: A preliminary search resulted in 832 studies. After all selection steps were performed, 12 articles were included. The selected studies were published between 1997 and 2010, whose samples consisted of children and adolescents with levels of relative body fat ranging from 20.7% to 41.4%. The methods used were: dual energy X-ray absorptiometry (58.3%), isotope dilution (41.6%), skinfold thickness (33.3%), hydrostatic weighing (25%), bioelectrical impedance analysis (25%), air displacement plethysmography (16.6%), and total body electrical conductivity (8.3%). CONCLUSIONS: Based on the analysis of the studies, isotope dilution and air displacement plethysmography methods were the most reliable, despite the limited number of studies. As for clinical use or for population-based studies, the equation of Slaughter et al. (1998), which uses the triceps and subscapular skinfolds thickness, showed the best results for assessment of body fat in this population.

Validade dos métodos para avaliação da gordura corporal em crianças e adolescentes por meio de modelos multicompartimentais: uma revisão sistemática / Validity of the methods to assess body fat in children and adolescents using multi-compartment models as the reference method: a systematic review

OBJETIVO: Analisar a validade de métodos para avaliação de gordura corporal em crianças e adolescentes. MÉTODOS: A busca foi realizada por dois pesquisadores independentes, nas bases eletrônicas MEDLINE, BioMed Central, SciELO e LILACS. Como critérios de inclusão, os artigos deveriam ser escritos nas línguas inglesa ou portuguesa, ter utilizado como medida critério modelos multicompartimentais, com medida de gordura corporal em crianças e adolescentes não atletas. RESULTADOS: A busca preliminar resultou em 832 artigos, e após todas as etapas de seleção 12 compuseram esta revisão. Os trabalhos selecionados foram publicados entre 1997 e 2010, com amostras formadas por crianças e adolescentes com níveis de gordura corporal relativa de 20,7-41,4%. Os métodos utilizados foram: absortometria radiológica de dupla energia (58,3%), diluição de isótopos (41,6%), espessura de dobras cutânea (33,3%), pesagem hidrostática (25%), impedância bioelétrica (25%), pletismografia por deslocamento de ar (16,6%) e condutividade elétrica corporal total (8,3%). CONCLUSÃO: A partir da análise dos estudos, concluímos que os métodos diluição de isótopos e pletismografia por deslocamento de ar foram os que se apresentaram mais confiáveis, apesar do número reduzido de investigações. Já para a utilização clínica e em estudos populacionais, a equação de Slaughter et al., que utiliza a espessura das dobras cutâneas tricipital e subescapular, foi a que apresentou melhores resultados para avaliação da gordura corporal nessa população.

OBJECTIVE: To analyze the validity of methods to assess body fat in children and adolescents using a systematic review. METHODS: The search was conducted by two independent researchers using the MEDLINE, BioMed Central, SciELO and LILACS electronic databases. For inclusion, the articles should be written in English or Portuguese, andmust have usedmulti-compartment models as the criterion measure of the model, with body fat measurement of whole body in non-athlete children and adolescents. RESULTS: A preliminary search resulted in 832 studies. After all selection steps were performed, 12 articles were included. The selected studies were published between 1997 and 2010, whose samples consisted of children and adolescents with levels of relative body fat ranging from 20.7% to 41.4%. The methods used were: dual energy X-ray absorptiometry (58.3%), isotope dilution (41.6%), skinfold thickness (33.3%), hydrostatic weighing (25%), bioelectrical impedance analysis (25%), air displacement plethysmography (16.6%), and total body electrical conductivity (8.3%). CONCLUSIONS: Based on the analysis of the studies, isotope dilution and air displacement plethysmography methodswere the most reliable, despite the limited number of studies. As for clinical use or for population-based studies, the equation of Slaughter et al. (1998), wich uses the triceps and subscapular skinfolds thickness, showed the best results for assessment of body fat in this population.