Abdominal Obesity In Adolescents Research Articles

Association between Sleep Quality and Cardiac Autonomic Modulation in Adolescents: A Cross Sectional Study.

Objective To analyze the impact of sleep quality/duration on cardiac autonomic modulation on physically active adolescents with obesity. Materials and Methods The present cross-sectional study included 1,150 boys with a mean age of 16.6 ± 1.2 years. The assessment of cardiac functions included the frequency domain of heart rate variability (HRV; low frequency - LF; high frequency - HF; and the ratio between these bands -LF/HF -, defined as the sympathovagal balance), and each parameter was categorized as low / high . Physical activity levels and sleep quality/duration were obtained by questionnaires. Abdominal obesity was assessed and defined as waist circumference > 80 th percentile. Results Poor sleep quality resulted in lower HF (odds ratio [OR]: 1.8; 95% confidence interval [95%CI]: 1.01-3.21]) regardless of physical activity and abdominal obesity. Moreover, the study found no association between sleep duration and HRV parameters in adolescents. Conclusion Sleep quality, not sleep duration, reduces parasympathetic cardiac modulation apart from other factors such as physical activity and abdominal obesity in adolescents.

Multilevel correlates of abdominal obesity in adolescents and youth living with HIV in peri-urban Cape Town, South Africa.

Chronic non-communicable disease comorbidities are a major problem faced by people living with HIV (PLHIV). Obesity is an important factor contributing to such comorbidities and PLHIV face an elevated risk of obesity. However, there is data paucity on the intersection of obesity and HIV in adolescents and youth living with HIV (AYLHIV) in sub-Saharan Africa. We therefore aimed to investigate the prevalence of abdominal obesity and associated multilevel factors in AYLHIV in peri-urban Cape Town, South Africa. We conducted a cross-sectional study enrolling AYLHIV aged 15-24 years attending primary healthcare facilities in peri-urban Cape Town in 2019. All measures, except for physical examination measures, were obtained via self-report using a self-administered electronic form. Our outcome of interest was abdominal obesity (waist-to-height ratio ≥ 0.5). We collected individual-level data and data on community, built and food environment factors. Data was summarized using descriptive statistics, stratified by obesity status. Multilevel logistic regression was conducted to investigate factors associated with abdominal obesity, adjusted for sex and age. A total of 87 participants were interviewed, 76% were female and the median age was 20.7 (IQR 18.9-23.0) years. More than two fifths had abdominal obesity (41%; 95% CI: 31.0-51.7%), compared to published rates for young people in the general population (13.7-22.1%). In multilevel models, skipping breakfast (aOR = 5.42; 95% CI: 1.32-22.25) was associated with higher odds of abdominal obesity, while daily wholegrain consumption (aOR = 0.20; 95% CI: 0.05-0.71) and weekly physical activity (aOR = 0.24; 95% CI: 0.06-0.92) were associated with lower odds of abdominal obesity. Higher anticipated stigma was associated with reduced odds of obesity (aOR = 0.58; 95% CI: 0.33-1.00). Land-use mix diversity (aOR = 0.52; 95% CI: 0.27-0.97), access to recreational places (aOR = 0.37; 95% CI: 0.18-0.74), higher perceived pedestrian and traffic safety (aOR = 0.20; 95% CI: 0.05-0.80) and having a non-fast-food restaurant within walking distance (aOR = 0.30; 95% CI: 0.10-0.93) were associated with reduced odds of abdominal obesity. The main limitations of the study were low statistical power and possible reporting bias from self-report measures. Our findings demonstrate a high prevalence of abdominal obesity and highlight multilevel correlates of obesity in AYLHIV in South Africa. An intersectoral approach to obesity prevention, intervening at multiple levels is necessary to intervene at this critical life stage.

Degree of food processing and association with overweight and abdominal obesity in adolescents.

ABSTRACTObjective To evaluate the association between the degree of food processing, overweight, and abdominal obesity in adolescents.Methods This is a cross-sectional study, with 576 adolescents aged 10 to 17 years, of both sexes. Food consumption was collected using the Food Frequency Questionnaire and foods classified as in natura or minimally processed, processed foods associated with culinary ingredients, and ultraprocessed foods. Sociodemographic data, body mass index, waist circumference and waist-to-height ratio were collected. The analysis was evaluated by the Mann-Whitney test and prevalence ratio with 95% confidence interval, considering p<0.05.Results An intake above the third quartile of processed foods associated with culinary ingredients (prevalence ratio of 1.64; 95%CI: 1.12-2.42) and ultraprocessed (prevalence ratio of 1.58; 95%CI: 1.07-2.34) was associated with a higher prevalence of overweight. Consumption above the third quartile of ultraprocessed foods was associated with a higher prevalence of abdominal obesity, assessed by waist circumference (prevalence ratio of 2.48; 95%CI: 1.41-4.36), and waist-height ratio (prevalence ratio of 2.09; 95%CI: 1.11-3.92).Conclusion A higher consumption of processed foods associated with culinary ingredients was related to being overweight, and ultraprocessed foods with overweight and abdominal obesity.

Relationship Between Dairy Consumption and Abdominal Obesity

Objective This cross-sectional study aimed to demonstrate the relationship between dairy consumption and abdominal obesity in adolescents. Method In total, 700 adolescents participated in this cross-sectional study. Sociodemographic characteristics, consumption of dairy, body mass index (BMI), waist circumference (WC), and waist/height (W/H) ratio were evaluated. The participants were divided into two groups as to whether their dairy consumptions were below or above 3 portions/d, according to the Turkey Dietary Guideline recommendations. Results The mean age of participants was 15.84 ± 1.23 years. The rate of girls (65.2%) who participated in this study was significantly higher than that of the boys (34.8%; p < 0.001). No statistically significant difference was found between the participants whose dairy consumption was below and above the specified limits in terms of BMI, WC, or W/H measurements. Energy intake (p < 0.05) and milk and cheese consumption (p < 0.001) were higher in boys than in girls. There was a significant negative correlation between dairy consumption and WC (r = −0.121), W/H ratio (r = −0.105), and BMI (r = −0.103) in girls (p < 0.05). It was found that a 1-unit increase in milk consumption can cause a 1.98-, 0.11-, and 0.552-fold decrease in WC, W/H ratio, and BMI in girls, respectively (p < 0.05; 95% confidence interval [−3.502, −0.471], [−0.020, −0.001], [−1.042, −0.062], respectively). Conclusions Inadequate milk consumption was related to increasing WC and WC may be one of the factors of abdominal obesity in girls. Therefore, it is of importance to raise awareness about milk and dairy consumption in adolescents.

BIRTH WEIGHT AND OVERWEIGHT IN ADOLESCENTS: THE ERICA PROJECT IN THE CITY OF RECIFE, PERNAMBUCO.

ABSTRACTObjective: To verify the association of anthropometric parameters at birth, socioeconomic and biological variables, physical activity, and parental nutritional status with overweight and abdominal obesity in adolescents.Methods: A cross-sectional study was carried out on 39 public and private schools in Recife (state of Pernambuco, Brazil). The sample consisted of 1,081 teenagers aged from 12 to 17 years. Data were collected from the Study of Cardiovascular Risks in Adolescents (ERICA). Body mass index according to age (BMI-for-age), waist circumference (WC), and waist-to-height ratio (WtHR) were considered as outcome variables, whereas the explanatory variables were birth weight, Röhrer’s Ponderal Index (RPI), biological and socioeconomic variables, physical activity, and parental nutritional status. The crude and adjusted prevalence ratios (PR) for the studied association were estimated by Poisson Regression.Results: The multivariate Poisson regression showed that the variable that remained significantly associated with overweight in adolescence was maternal overweight, PR=1.86 (95% confidence interval [95%CI] 1.09-3.17). High birth weight also remained significantly associated with abdominal obesity assessed by WC, PR=3.25 (95%CI 1.0-9.74).Conclusions: High birth weight may be a marker for abdominal obesity in adolescence; and high maternal BMI, for overweight.

ASSOCIATED FACTORS WITH THE ISOLATED AND SIMULTANEOUS PRESENCE OF OVERWEIGHT AND ABDOMINAL OBESITY IN ADOLESCENTS.

ABSTRACTObjective: To analyze the sociodemographic and lifestyle factors associated with excessive weight (EW), abdominal obesity (AO) and the simultaneous presence of EW and AO in adolescents from Southern Brazil.Methods: Cross-sectional study with 583 adolescents (11 to 17 years old) of Criciúma, Santa Catarina, Brazil. EW was assessed by body mass index (BMI) and AO by waist circumference (WC). The independent variables analyzed were gender, age, maternal schooling, balanced diet, physical activity, cigarette use, excessive alcohol use and screen time. Binary logistic regression was used to estimate Odds Ratios (OR) and 95% confidence intervals (95%CI).Results: Boys had 58% higher likelihood of having EW (OR 1.58; 95%CI 1.08-2.29; p<0.05). Younger age group (11 to 14 years) was directly associated with higher likelihood of EW (OR 6.07; 95%CI 4.05-9.11; p<0.05). Adolescents whose mothers had higher education had 75% more likelihood of having AO (OR 1.75; 95%CI 1.01-3.00; p<0.05). Higher likelihood for EW and AO (OR 1.84; 95%CI 1.01-3.34; p<0.05) was identified in younger adolescents (11 to 14 years).Conclusions: Boys and younger age (11 to 14 years) were associated with a higher likelihood of EW. Adolescents whose mothers studied nine years or more were more likely to have AO. The younger age group (11 to 14 years) was associated with greater chances for the simultaneous presence of EW and AO.

Prevalence of general and abdominal obesity among adolescents attending independent schools in Qatar

PurposeThe purpose of this paper is to determine the prevalence of general and abdominal obesity among adolescents attending independent schools in Qatar.Design/methodology/approachesA school-based cross-sectional study was conducted in November-December 2013 in 23 secondary schools. A total of 1,161 students aged 14 to 19 year olds were randomly selected using a multistage stratified cluster random sampling technique. Body weight, height and waist circumference (WC) were measured using standard protocol. The International Obesity Task Force (IOTF) age- and sex-specific body mass index (BMI) reference were used to define overweight and obesity. Abdominal obesity (AO) was defined by waist to height ratio (WHtR ≥ 0.5) and by sex- and age-specific WC cut-off values.FindingsThe prevalence of overweight and obesity among the study population was 20.6 and 20.7%, respectively. The highest rate of overweight and obesity was observed among boys, and the youngest age group. The rate of obesity defined by either WC/or WHtR was higher than that assessed by BMI. The prevalence of AO assessed by WC and WHtR was 48.8 and 46.9%, respectively. The rate of AO was significantly higher (p < 0.05) among boys compared to girls for both assessment criteria. The proportion of adolescents with AO (WHtR ≥ 0.5) according to BMI was 17.3%, 80.8% and 97.1% for adolescents with normal, overweight and obesity had AO, respectively. Being male was significantly associated with higher odds of having both general obesity and AO.Originality/valueThe study revealed a high prevalence of general and abdominal obesity in adolescents in Qatar. Waist measures appear to be an important indicator in identifying adolescents at risk and should be included as screening tools for cardiometabolic risk.

Is there a relationship between dairy products consumption and abdominal obesity in adolescents?

Is there a relationship between dairy products consumption and abdominal obesity in adolescents?

Abdominal obesity in adolescents: Development of age-specific waist circumference cut-offs linked to adult IDF criteria.

The purpose of this study was to develop age- and sex-specific waist circumference (WC) cut-off points, linked to older adolescent and adult criteria for abdominal obesity, to be applied to children in the clinical setting. A total of 16,788 adolescents aged 10 to 16 years were assessed for WC. Smoothed age and sex-specific WC curves were obtained using Cole's LMS method. Percentiles that corresponded to the International Diabetes Federation (IDF) recommendations used for older adolescents and adults (16+ years old) were the 97th percentile for boys and the 87th percentile for girls. Using these cutoffs, a total of 368 boys and 1138 girls were categorized as abdominally obese, in contrast to 1654 boys and 987 girls that were identified using the current IDF pediatric criteria (90th percentile). We provide age- and sex-specific cut-off points that can be used to identify abdominal obesity in adolescents. The present findings provide a tool that can be used in the clinical setting for the early detection and prevention of adult obesity. Population-specific cutoffs may be required for pediatric ages to diagnose children at risk.

Abstract P135: Abdominal Obesity is Associated With DNA Methylation in Cardiovascular Health Related Genes Among Adolescents

Background: Obesity, especially abdominal obesity, is a risk factor for coronary artery disease (CAD) in various populations. Little is known regarding the role of epigenetics in the association between abdominal obesity and cardiovascular health in adolescents. Hypothesis: Abdominal and especially visceral obesity is associated with DNA methylation in genes related to cardiovascular health among adolescents. Methods: We used data from a sample of 263 adolescents participating in the population-based Penn State Child Cohort follow-up exam (N=421). Dual-energy X-ray absorptiometry was used to measure visceral and subcutaneous fat areas (VAT; SAT, in cm 2 ) in each participant. We extracted DNA from peripheral leukocytes and subjected it to enhanced, reduced representation bisulfite sequencing. A high-throughput assay provided single nucleotide resolution of DNA methylation in cytosine-phosphate-guanine (CpG) sites and surrounding regions. We excluded bases with &lt; 10x coverage or available from &lt; 20 individuals. We analyzed a total of 1,609,424 methylation sites. We used linear regression models to assess the association between site-specific methylation level (expressed as %) and VAT and SAT. We adjusted all models for age, race, sex, and body mass index (BMI) percentile. We used Bonferroni-adjusted statistical tests to identify sites significantly related to VAT and separately, SAT. We mapped the VAT- and SAT-associated sites to the hg19 assembly and subjected them to Ingenuity Pathway Analysis (IPA) wherein mapped gene sets were examined for enrichment of downstream function and diseases. Results: On average, the sample was 55% male, 79% white and aged 16.7 (standard deviation = 2.2) years. VAT and SAT were significantly associated with methylation at 296 sites within 193 genes and 101 sites within 87 genes, respectively. Among them, seven genes related to VAT and five related to SAT were associated with CAD. IPA revealed that CAD-related genes were significantly enriched in both gene sets (for VAT: p=1.97x10 -2 ; SAT: p=9.67x10 -3 ). Genes related to VAT also were significantly enriched in endothelial activation (p=8.16x10 -3 ), fibrogenesis (p=5.01x10 -5 ), and dyslipidemia (p=7.99x10 -3 ). Indeed, higher VAT was associated with hypomethylation of CD14 and hypermethylation of GNMT , while higher SAT was associated with hypermethylation of ADRB1 and hypomethylation of TUBB4A . Conclusion: If externally validated, our data would suggest that (1) abdominal obesity in adolescence is associated with DNA methylation of genes related to cardiovascular health, independent of BMI; and (2) visceral adiposity has a more prominent association with cardiovascular health through DNA methylation of genes with roles in atherogenesis.

Tempo de tela como discriminador de excesso de peso, obesidade e obesidade abdominal em adolescentes

DOI: http://dx.doi.org/10.5007/1980-0037.2016v18n5p539 Many researches have concluded that the time spent in front of TV, computer and other screen-type devices is an important risk factor for overweight and obesity. The aim of this study was to identify the discriminatory power and to propose screen time cutoff points for overweight, obesity and abdominal obesity in adolescents. This household survey had cross-sectional design with sample of 613 adolescents aged 15-18 years living in a city in northeastern Brazil. The predictive power and cutoffs points of screen time for the outcomes of interest were identified by receiver operating characteristic curves (ROC). The study adopted 95% confidence interval (CI). Screen time during one day on the weekend was a good discriminator for the presence of overweight only among girls, area under the curve ROC = 0.59 (0.51 to 0.65). There were no areas under the ROC curve with statistical significance to discriminate obesity and abdominal obesity. Remain sitting for accumulated four hours per day during the weekend discriminates presence of overweight among girls (sensitivity = 60.9%, specificity = 52%). The long time spent in front of TV, computer and other screen-type devices on the weekend discriminate overweight in girls.

Prevalence of abdominal obesity in adolescents: association between sociodemographic factors and lifestyle

ObjectiveTo estimate the prevalence of abdominal obesity and verify the association with sociodemographic factors (gender, school shift, ethnicity, age, maternal education and economic status) and lifestyle (alcohol consumption, sleep, soft drink consumption, level of physical activity and sedentary behavior) in adolescents in Southern Brazil. MethodsThis was a cross-sectional epidemiological study of 930 adolescents (490 girls) aged 14–19 years, living in the city of São José, SC, Brazil. A self-administered questionnaire was used to collect sociodemographic and lifestyle data. Abdominal obesity was measured through the waist circumference and analyzed according to gender and age. Descriptive statistics (absolute and relative frequency, mean and standard deviation) and binary logistic regression, expressed as Odds Ratios (OR) and 95% confidence interval (95%CI) were employed, with p<0.05 being considered statistically significant; the SPSS 17.0 software was used for the statistical analyses. ResultsThe prevalence of abdominal obesity was 10.6% for the total sample (10.5% male, 10.8% female). Adolescents that watched television daily for two or more hours (OR=2.11, 95%CI 1.08–4.13) had a higher chance of having abdominal obesity and adolescents whose mothers had fewer than eight years of schooling (OR=0.56; 95%CI from 0.35 to 0.91) had a lower chance of having abdominal obesity. ConclusionsApproximately one in 10 adolescents had abdominal obesity; the associated factors were maternal schooling (≥8 years) and television screen time (≥2h/day).

Abdominal obesity and its association with socioeconomic factors among adolescents from different living environments.

Socioeconomic status has been associated with obesity in children and adolescents. This association may be dependent according with where adolescents lives. The aim of this study was to evaluate the association between different socioeconomic indicators such as parental education and occupation and socioeconomic status with abdominal obesity in adolescents from two observational studies: the Healthy Lifestyle in Europe by Nutrition in Adolescence cross-sectional study (HELENA-CSS) and the Brazilian Cardiovascular Adolescent Health (BRACAH) study. European (n = 3192, aged 12.5-17.5 years, with 53.1% girls from HELENA-CSS) and Brazilian (n = 991, aged 14-18 years, with 54.5% girls from BRACAH study) adolescents from two cross-sectional studies were included in this analysis. Complete data on waist circumference (WC), height, socioeconomic status indicators and several confounders were collected. Socioeconomic indicators were measured using a self-reported questionnaire in order to assess the family social status of the adolescents. Multilevel linear regression models were used to examine associations, and results were adjusted for potential confounders. Adjusted results showed inverse associations between mother's and father's education levels (p < 0.001) and father's occupation level (p < 0.001) with waist-to-height ratio (WHtR) and WC in HELENA-CSS girls. Similarly in European girls, socioeconomic indicators by socioeconomic status and maternal occupation level were associated with WHtR. In HELENA-CSS boys, the same significant association was found between WHtR and WC with maternal occupation level. Moreover, in European boys WHtR was also associated with parental education. In Brazilian adolescents, both indicators of abdominal obesity did not remain associated with the independents variables, after adjustment for potential confounders. Abdominal obesity was associated with socioeconomic indicators in higher-income countries, but this association was not observed in a lower-middle-income country.

Snacking Behavior and Obesity among Female Adolescents in Isfahan, Iran

Background and Objective: The high prevalence of obesity in the pediatric age groups draws attention to lifestyle factors including diet and physical activity. Data on obesity in adolescents and their snacking behavior are conflicting. This study aimed to assess the association of snacking behavior and obesity among female adolescents in Isfahan, Iran.Subjects and Design: This cross-sectional study was carried out on 265 female Isfahanian students who were chosen by systematic cluster random sampling. Dietary intake was assessed using a validated self-administered semiquantitative food frequency questionnaire that included 53 food items. Snacking behavior was defined by healthy snack score in combination with the frequency of snack intake.Results: Individuals who consumed more healthy snacks and those with snacking frequency of 4 times a day or more had significantly lower weight, body mass index (BMI), and waist circumference (p < 0.001). Decreased consumption of healthy snacks was significantly associated with a greater chance of being overweight, generally obese, and abdominally obese among adolescents (odds ratio [OR] = 1.98; 95% confidence interval [CI], 1.00–3.14, ptrend = 0.04 and OR = 2.10; 95% CI, 1.01–3.13, ptrend = 0.04, respectively). Frequency of snack intake was inversely related to overweight, general obesity, and abdominal obesity (OR = 3.23; 95% CI, 1.73–5.61, ptrend = 0.03 and OR = 1.84; 95% CI, 1.05–3.20, ptrend = 0.04, respectively). Healthy snack score in combination with frequency of snacking showed that those in the lowest tertile of snacking who consumed snacks less than 4 times/day had the highest risk of obesity compared to other categories (OR = 2.09, 95% CI, 1.11–3.20, p < 0.001).Conclusion: More frequent consumption of healthy snacks is associated with decreased prevalence of overweight, general obesity, and abdominal obesity in adolescents. Further studies, in particular of a prospective nature, are required to examine this association in other populations.

Habitual sleep variability, mediated by nutrition intake, is associated with abdominal obesity in adolescents

ObjectiveTo investigate habitual sleep duration (HSD) and habitual sleep variability (HSV) in relation to abdominal obesity and nutrient intake as mediating factors in adolescents. MethodsWe analyzed data from 305 adolescents who participated in the Penn State Child Cohort follow-up examination. An actigraphy device was used for seven consecutive nights to calculate HSD and HSV. Abdominal obesity was assessed by dual-energy x-ray absorptiometry. The Youth/Adolescent Food Frequency Questionnaire was used to obtain daily total caloric, protein, fat, and carbohydrates intakes. Linear regression models were used to associate HSD and HSV with abdominal obesity and to qualitatively identify mediating factors. The mediating effect was quantitatively estimated by mediation models. ResultsAfter adjusting for major covariates and HSD, higher HSV was significantly associated with abdominal obesity measures. For example, with 1-hour increase in HSV, android/gynoid fat ratio and visceral fat area increased by 0.02 cm2 (standard error = 0.01, p = 0.03) and 6.86 cm2 (standard error = 2.82, p = 0.02), respectively. HSD was not associated with abdominal obesity in HSV-adjusted models. Total caloric, fat, and carbohydrate intakes were significant mediating factors. For instance, 20% of the association between HSV and visceral fat can be attributed to carbohydrate intake. ConclusionsHigher HSV, not HSD, is significantly associated with abdominal obesity, which can be partially explained by increased caloric intake, especially from carbohydrate, in adolescents. This study suggests that more attention should be paid to establish and maintain regular sleep patterns in adolescents.

The effects of phthalate and nonylphenol exposure on body size and secondary sexual characteristics during puberty

Some phthalic acid esters (PAEs) and nonylphenol (NP) are endocrine-disrupting chemicals (EDCs) that are widely used in consumer products. Consequently, the general population is exposed simultaneously to both groups of chemicals. To investigate the single- and co-exposure effects of PAEs (DMP, DEP, DnBP, DiBP, BBzP, and DEHP) and NP on obesity and pubertal maturity to compare the body sizes of general adolescents with the complainants of the phthalate-tainted foods scandal that occurred in Taiwan. This study included 270 general adolescents aged 6.5-15.0 years and 38 complainants aged 6.5-8.5 years. Nine metabolites of the five PAEs and of NP were measured in urine. We used a questionnaire to evaluate pubertal maturity, measured anthropometric indices (APs) to assess body size, and collected urine samples to measure the two groups of chemicals. We found that urinary PAE metabolite concentrations (specifically, metabolites of DEP, DnBP, DiBP, and DEHP) were positively associated with the APs for abdominal obesity (including skinfold thickness, waist circumference, waist-to-height ratio, and waist-to-hip) and indicated a dose-response relationship. Mono-methyl phthalate (MMP) exposure was inversely associated with pubarche among boys. The daily intake of DEHP in general adolescents exceeded the reference doses (RfD-20 μg/kgbw/day) and tolerable daily intake (TDI-50 μg/kgbw/day) by 3.4% and 0.4%, respectively. No associations were observed between NP exposure or co-exposure and the APs or pubertal maturity. No significant differences were observed between general adolescents and the complainants with regard to weight, height, or BMI. The study suggests that PAE (specifically, DEP, DnBP, DiBP, and DEHP) exposure is associated with abdominal obesity in adolescents and that the APs for abdominal obesity are more sensitive than BMI for measuring obesity among adolescents. We suggest that the RfD and TDI for PAEs should be revised to provide sufficient protection.

Abstract MP70: Habitual Sleep Variability, Mediated by Energy Intake, is Associated with Abdominal Obesity in Adolescents

Introduction: Although self-reported sleep duration has been associated with obesity, study of the association between objectively-measured habitual sleep pattern and the more metabolically relevant abdominal obesity, and the mediation factors for such an association, is limited. Hypothesis: We assessed the hypothesis that objectively-measured variability, mediated by excessive energy intake, is associated with abdominal obesity in adolescents. Methods: We used data from 421 adolescents in the Penn State Child Cohort follow-up examination. Actigraphy was used for 7 consecutive nights to calculate each participant’s mean sleep duration as habitual sleep duration (HSD) and the standard deviation of the mean as habitual sleep variability (HSV). Abdominal obesity was assessed by dual-energy x-ray absorptiometry as Android/Gynoid Fat Ratio and visceral fat area . Youth/Adolescents Food Frequency Questionnaire was used to obtain daily caloric, fat, carbohydrate, and protein intakes one year prior to the study. The R-based Mediation Effect Models were used to assess the association between sleep pattern and abdominal obesity, and quantitatively estimate the mediation effects of caloric intake and of other factors not analyzed in this report. Results: As shown in the table, after controlling for major confounders and BMI percentile, HSV was significantly and consistently associated with both abdominal obesity measures. The Mediation analysis consistently indicated a significant mediation effect of caloric intake, especially carbohydrate intake. For example, 20% of the association between HSV and visceral fat could be attributed to carbohydrate intake, while 80% by other factors not analyzed. HSD was not associated with abdominal obesity. Conclusions: Higher HSV, not HSD, is associated with abdominal obesity, which can be partially explained by increased caloric intake, especially from carbohydrate, in adolescents. More studies are needed to identify other mediation factors in the association.

Body weight dissatisfaction and its correlates among Brazilian adolescents

OBJECTIVE: This study examined the prevalence of body weight dissatisfaction and its relationship to physical activity and nutritional status in adolescents. METHOD: The study enrolled 2,288 adolescents. The dependent variable was body weight dissatisfaction. The independent variables were physical activity and nutritional status. The confounders were gender, and economic condition. Associations between dependent and independent variables were analyzed through the chi-square test and the magnitude of the associations was estimated by Poisson regression. RESULTS: A total of 56.6% of adolescents were not satisfied with their weight, with 17.9% wanting to increase it, while 37.7% wanted to decrease their weight. In boys and girls, body weight dissatisfaction was associated with nutritional status, abdominal obesity and physical activity in crude analyses. After adjustments, nutritional status and abdominal obesity remained significantly associated to body weight dissatisfaction in both sexes. CONCLUSION: A high prevalence of body weight dissatisfaction was identified, which was associated with the nutritional status and abdominal obesity in adolescents.

Associação entre insatisfação com a imagem corporal e indicadores antropométricos em adolescentes

O objetivo foi verificar a associação entre a insatisfação com a imagem corporal, o índice de massa corporal (IMC), a adiposidade corporal e a obesidade abdominal em adolescentes. Participaram 637 adolescentes (11-17 anos) de ambos os sexos. Foram medidos massa corporal, estatura, perímetro do abdômen, dobras cutâneas do tríceps e perna medial e, coletadas informações referentes a imagem corporal. O IMC, a obesidade abdominal e a adiposidade corporal foram usados como referência em relação ao desfecho. A prevalência de insatisfação com a imagem corporal foi de 60% (rapazes = 54,3%, moças = 65,2%; p &lt; 0,05). Os rapazes com IMC baixo e obesidade abdominal apresentaram, respectivamente, 4,31 e 4,93 vezes mais chance de insatisfação corporal. As moças com IMC alto e adiposidade corporal alta apresentaram, respectivamente, 6,81 e 1,95 vezes mais chance de insatisfação corporal. Enquanto nos rapazes o IMC baixo e a obesidade abdominal apresentaram associação com a insatisfação corporal; nas moças o IMC e a adiposidade corporal elevados estiveram associados.

Relationship of milk intake and physical activity to abdominal obesity among adolescents

What is already known about this subject Diet and physical activity (PA) are recognized as important factors to prevent abdominal obesity (AO). Studies have found an inverse relationship between milk intake or milk products and body weight and/or body fat in children and adolescents. Evidence suggests that low levels of PA are associated with AO in youth. What this study adds Our study explored the combined association of milk intake and PA on AO in adolescents, which are most often studied in isolation. Our findings suggested that adolescents with high milk intakes, regardless of whether they were active or low active, were less likely to have AO. Our findings could have a great epidemiological interest and bring important evidence in the field of AO management among adolescents. Diet and physical activity (PA) are recognized as important factors to prevent abdominal obesity (AO), which is strongly associated with chronic diseases. Some studies have reported an inverse association between milk consumption and AO. This study examined the association between milk intake, PA and AO in adolescents. A cross-sectional study was conducted with 1209 adolescents, aged 15-18 from the Azorean Archipelago, Portugal in 2008. AO was defined by a waist circumference at or above the 90th percentile. Adolescent food intake was measured using a semi-quantitative food frequency questionnaire, and milk intake was categorized as 'low milk intake' (<2 servings per day) or 'high milk intake' (≥2 servings per day). PA was assessed via a self-report questionnaire, and participants were divided into active (>10 points) and low-active groups (≤10 points) on the basis of their reported PA. They were then divided into four smaller groups, according to milk intake and PA: (i) low milk intake/low active; (ii) low milk intake/active; (iii) high milk intake/low active and (iv) high milk intake/active. The association between milk intake, PA and AO was evaluated using logistic regression analysis, and the results were adjusted for demographic, body mass index, pubertal stage and dietary confounders. In this study, the majority of adolescents consumed semi-skimmed or skimmed milk (92.3%). The group of adolescents with high level of milk intake and active had a lower proportion of AO than did other groups (low milk intake/low active: 34.2%; low milk intake/active: 26.9%; high milk intake/low active: 25.7%; high milk intake/active: 21.9%, P = 0.008). After adjusting for confounders, low-active and active adolescents with high levels of milk intake were less likely to have AO, compared with low-active adolescents with low milk intake (high milk intake/low active, odds ratio [OR] = 0.412, 95% confidence intervals [CI]: 0.201-0.845; high milk intake/active adolescents, OR = 0.445, 95% CI: 0.235-0.845). High milk intake seems to have a protective effect on AO, regardless of PA level.