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J Fleta

Publications and source records attributed to J Fleta.

At least 19 recordsLinked to original sources
PubMed2006

Anthropometric body fat composition reference values in Spanish adolescents. The AVENA Study.

OBJECTIVE: To determine reference values for body mass index (BMI), sum of six skinfolds (sigma6 skinfolds) and body fat percentage (BF%) in Spanish adolescents aged 13-18 years, included in the AVENA Study (Alimentación y Valoración del Estado Nutricional en Adolescentes: Food and Assessment of the Nutritional Status of Adolescents). DESIGN: Multicentre cross-sectional study. SETTING: Representative sample of Spanish adolescents. SUBJECTS: The population was selected by means of a multiplestep, simple random sampling. The final number of subjects included in the AVENA Study was 2859 adolescents; 2160 adolescents had a complete set of anthropometric measurements and were then included in this study (1109 males and 1051 females). INTERVENTIONS: Weight, height and six skinfold thicknesses were measured. As indices of total adiposity, we calculated BMI, summation sigma6 skinfolds and BF% with the formulas described by Slaughter et al. RESULTS: Sigma6 skinfolds and BF% in each age group were significantly higher in females than in males. In males, age showed a significant effect for BMI, sigma6 skinfolds and BF%; however, in females, the effect was only significant for BF%. The percentile distribution was more disperse towards higher sigma6 skinfolds and BF% values in males when compared with females. CONCLUSIONS: The presented percentile values will help us to classify adolescents in comparison with a well-established reference population, and to estimate the proportion of adolescents with high or low adiposity amounts. SPONSORSHIP: The AVENA-Study was supported by the Spanish Ministry of Health (FIS 00/0015), and grants from Panrico SA, Madaus SA and Procter and Gamble SA. This study was also supported by Instituto de Salud Carlos III (Spain), RCESP (C03/09) and Spanish Ministry of Education (AP2003-2128).

Adipose Tissue↗
PubMed2005

Body fat measurement in adolescents: comparison of skinfold thickness equations with dual-energy X-ray absorptiometry.

OBJECTIVE: To compare the most commonly used equations to predict body fatness from skinfold thickness, in male and female adolescents, with dual-energy X-ray absorptiometry (DXA) as a reference method of fatness measurement. DESIGN: Cross-sectional nutrition survey. SETTING: General adolescent population from Zaragoza (Spain). SUBJECTS AND METHODS: A total of 238 Caucasian adolescents (167 females and 113 males), aged 13.0-17.9 y, were recruited from 15 school groups in 11 public and private schools. The percentage fat mass (%FM) was calculated by using skinfold-thickness equations. Predicted %FM was compared with the reference %FM values, measured by DXA. The lack of agreement between methods was assessed by calculating the bias and its 95% limits of agreement. RESULTS: Most equations did not demonstrate good agreement compared with DXA. However, in male adolescents, Slaughter et al equations showed relative biases that were not dependent on body fatness and the limits of agreement were narrower than those obtained from the rest of equations. In females, Brook's equation showed nonsignificant differences against DXA and the narrowest 95% limits of agreement. Only biases from Brook and Slaughter et al equations were not dependent on body fatness in female adolescents. CONCLUSIONS: Accuracy of most of the skinfold-thickness equations for assessment of %FM in adolescents was poor at the individual level. Nevertheless, to predict %FM when a relative index of fatness is required in field or clinical studies, Slaughter et al equations may be used in adolescents from both sexes and the Brook equation in female adolescents.

Absorptiometry, Photon↗
PubMed2005

Secular trends in waist circumference in Spanish adolescents, 1995 to 2000-02.

Two studies, in 1995 and 2000-02, were compared to assess changes in waist circumference in adolescents. Between the two time periods, waist circumference increased significantly in males at 13 years and in females at 14 years. Significant changes in waist circumference were observed during the study period; the rates of change were 0.53 and 0.86 cm/y in boys and 0.67 and 0.87 cm/y in girls. Future morbidity in adolescents may be affected due to accumulation of excess central fat.

Adipose Tissue↗
PubMed2003

Psyllium fibre and the metabolic control of obese children and adolescents.

In children and adolescents from developed countries, obesity prevalence has strongly increased in the last decades and insulin resistance and impaired glucose tolerance are frequently observed. Some dietary components such as low glycemic index foods and dietary fibre could be used in order to improve glucose homeostasis in these children. Psyllium or ispaghula husk (the husk of the seeds of Plantago ovata) is a mixture of neutral and acid polysaccharides containing galacturonic acid with a ratio of soluble/insoluble fibre of 70/30. Some foods could potentially be enriched with psyllium, like breads, breakfast cereals, pasta and snack foods. The aim of this review was to assess the usefulness of psyllium in the management of obese children and adolescents with abnormalities of carbohydrate and lipid metabolism. After psyllium supplementation, the percentage change in postprandial glucose in type 2 diabetes patients, ranged from -12.2 to -20.2%. In hypercholesterolemic children, the effect of psyllium in LDL-cholesterol serum concentrations ranged from 2.78 to -22.8%; the effect in HDL-cholesterol from -4.16 to 3.05%; and the effect on triglycerides from 8.49 to -19.54%. The reviewed evidence seems to show that psyllium improves glucose homeostasis and the lipid and lipoprotein profile; however, more well controlled trials and further studies are needed to clarify it's effects and the mechanisms involved.

Adolescent↗
PubMed2002

Determinants of resting energy expenditure in obese and non-obese children and adolescents.

Resting energy expenditure (REE) is the largest component of total daily energy expenditure. Objectives of this study were to examine whether differences in REE exist after obesity develops in a group of children and adolescents, and to determine the effects of body composition, gender, age, pubertal development and parental obesity on REE. In 116 Caucasian children and adolescents (57 obese and 59 non-obese), aged 7.8 to 16.6 years, REE was assessed by open-circuit indirect calorimetry and different anthropometric variables and bioelectrical impedance were obtained (weight, height, skinfold thicknesses, waist and hip circumferences). Anthropometric indices and body compartments were calculated: the body mass index, surface area (SA), fat-free mass (FFM), fat-mass (FM) and percentage of FM. Differences between obese and non-obese subjects were tested and stepwise multiple regression analysis was performed with REE as dependent variable. Results show that REE was significantly higher in obese than in non-obese children and adolescents but REE/FFM ratio was not significantly different between these groups. In the non-obese group, FFM explained 73.1% of the variability in REE and gender, age and SA added 3.8%, 2.6%, and 2.6% to it, respectively. In the obese group, FFM was also the most powerful predictor of REE with 72.3%, followed by waist circumference and age with 2.5% and 2.1%, respectively. These results show that REE differences between obese and lean children do not seem to justify the maintenance of obesity. The main determinant of REE is FFM in both groups. No significant contribution of FM, pubertal development or parental obesity in REE was found in children and adolescents.

Adipose Tissue↗
PubMed2002

Resting energy expenditure in children and adolescents: agreement between calorimetry and prediction equations.

BACKGROUND AND AIMS: To assess the degree of agreement between indirect calorimetry and five equations commonly used to predict resting energy expenditure (REE) in obese and non-obese children and adolescents. METHODS: In 116 children and adolescents (57 obese and 59 non-obese) aged between 7.8 and 16.6 years, REE was measured (MREE) by open-circuit indirect calorimetry under standardized conditions. REE was predicted (PREE) in all subjects with equations from the Food and Agriculture/World Health Organization/United Nations University (FAO/WHO/UNU), Maffeis et al., Harris and Benedict, and two from Schofield: one using weight (W) and one using height and weight (H-W). Agreement between indirect calorimetry and equations was assessed following the Bland-Altman method. RESULTS: In the entire cohort group, only data from FAO/WHO/UNU, Schofield-W and Schofield-HW equations showed non-statistic differences against calorimetry results. When agreement between equations and calorimetry was tested, Schofield-HW equation showed the lowest mean MREE-PREE difference: 3.7 kcal/d (limits of agreement -293 and 300 kcal/d; 95% confidence interval for the bias -24.0 to 31.5 kcal/d) and the best agreement. Group by group, equations which obtained the best agreement were: FAO/WHO/UNU in girls, Schofield-HW in boys, Schofield-HW in obese, and Schofield-W in non-obese. CONCLUSIONS: Until more accurate prediction equations are developed, we recommend Schofield-HW equations for REE studies with a mixed population of obese and non-obese children and adolescents; however, FAO/WHO/UNU equation may also be useful in girls and Schofield-W equation in non-obese children.

Adolescent↗
PubMed2002

Leptin and metabolic syndrome in obese and non-obese children.

Metabolic syndrome is characterized by a clustering of metabolic abnormalities: insulin resistance - hyperinsulinemia, dyslipidemia (high triglycerides and low HDL - cholesterol serum concentrations), impaired glucose tolerance and/or type 2 diabetes, and hypertension. The aim of this study was to analyse the role of different variables of metabolic syndrome, including leptin, in 74 non-obese children and 68 children with non-syndromal obesity. As metabolic syndrome variables, we have included body mass index, waist circumference, trunk-to-total skinfolds (%), systolic blood pressure, diastolic blood pressure, glucose, uric acid, fasting insulin, triglycerides and high-density lipoprotein-cholesterol (HDL-C). Factor analysis showed 4 factors in each group. In non-obese children, waist circumference, BMI, fasting insulin, triglycerides, trunk-to-total skinfolds (%), leptin and uric acid loaded positively on factor 1, and HDL-C loaded negatively on this factor; systolic and diastolic blood pressure had high positive loadings in factor 2; HDL-C and leptin showed positive loadings and triglycerides and uric acid, negative loadings in factor 3; and, finally, glucose and insulin showed positive loadings in factor 4. These four factors explained 72.16 % of the total variance in the non-obese group. In obese children, BMI, waist circumference, leptin, diastolic blood pressure and systolic blood pressure loaded positively on factor 1; diastolic blood pressure, trunk-to-total skinfolds (%), uric acid and systolic blood pressure showed high positive loadings in factor 2; fasting insulin, glucose and triglycerides showed positive loadings in factor 3; and, finally, triglycerides showed positive loadings and HDL-C negative loadings in factor 4. These four factors explained 74.18 % of the total variance in the obese group. Our results point to a different homeostatic control of metabolic syndrome characteristics in obese and non-obese children. Leptin seems to play a key underlying role in metabolic syndrome, especially in the obese group.

Blood Glucose↗
PubMed2002

Waist circumference for the screening of the metabolic syndrome in children.

AIM: To identify the best anthropometric predictor of the metabolic syndrome in children. METHODS: Screening performance was evaluated in a clinical setting. The study included 140 children: 72 non-obese and 68 with non-syndromal obesity. Body mass index (BMI), waist circumference and triceps/subscapular skinfolds ratio were used as predictor variables, and systolic blood pressure, diastolic blood pressure, glucose, uric acid, fasting insulin, triglycerides and HDL-C as metabolic syndrome variables. RESULTS: The areas under the receiver operating characteristic (ROC) curves were 0.849 (95% CI: 0.780, 0.919) for BMI, 0.868 (95% CI: 0.801,0.934) for waist circumference and 0.834 (95% CI: 0.757,0.910) for the triceps/subscapular skinfolds ratio. No statistically significant differences were found for the three areas under the ROC curves. The point on the ROC curve closest to 1 corresponded to the 65th percentile for BMI, to the 70th percentile for waist, and to the 40th percentile for the triceps/subscapular skinfolds ratio. CONCLUSION: Waist circumference seems to be the best predictor of children with the metabolic syndrome in paediatric clinical settings.

Adipose Tissue↗
PubMed2001

Secular increases in body fat percentage in male children of Zaragoza, Spain, 1980-1995.

BACKGROUND: Data on temporal changes on total body fat percentage (TBF%) are scarce, and no such data are known to exist in Spain. The aim of our study was to describe secular increases in TBF% in male children and adolescents of Zaragoza, Spain, from 1980 to 1995. METHODS: The samples analyzed in the present study have been included in two cross-sectional surveys conducted in 1980 and 1995. The samples selected for the 1980 and 1995 surveys comprised 1553 and 701 male children with ages ranging from 6.0 to 14.9 years. Weight, height, and four skinfold thicknesses were measured. From these measurements we have calculated TBF%. RESULTS: Concerning body mass index (BMI), we have observed significant increases from 8.5 to 11.5 years, ranging in this age group from 0.80 to 1.45 kg/m(2). TBF% showed significant increases at all age groups, with percentage increases of 2.46% at 13.5 years and 6.03% at 11.5 years. CONCLUSIONS: We have shown a secular increase in TBF% in children aged 6.0 to 15.0 years that is greater than the increase in BMI. The similarity of our findings for both relative weight and skinfold thickness, even with less significant differences for BMI, suggests that, in children of Zaragoza, Spain, adiposity has increased during the 1980-1995 period.

Adipose Tissue↗
PubMed2001

Sociodemographic factors and trends on overweight prevalence in children and adolescents in Aragón (Spain) from 1985 to 1995.

From 1985 to 1995, the Aragón School Health Examination Surveys staff has surveyed the whole population of children (age 6-7 years) and adolescents (age 13-14 years). A total of 90,997 children (age 6-7 years) were examined in the nine cross-sectional surveys conducted between 1985 and 1995. A total of 106,284 adolescents (age 13-14 years) were also examined. We defined overweight when the body mass index was > or = 95th percentile. The measure of association between overweight and the other variables studied was the odds ratio, which was calculated by logistic regression. In the children and adolescents studied, the probability to be overweight was higher in the rural than in the urban areas. In the adolescents, the probability to be overweight was higher in the public than in the private schools. Our results also show a significant increase in the prevalence of overweight children in the region of Aragón (Spain) during the 1985-1995 decade, especially in males. Prevention of overweight in the populations at risk would help reduce social inequality in health, a major challenge for public health policy.

Adolescent↗
PubMed2001

Secular changes in body fat patterning in children and adolescents of Zaragoza (Spain), 1980-1995.

OBJECTIVE: To examine whether children and adolescents of Zaragoza (Spain) are becoming centrally obese to a greater extent than would be predicted by their relative body weights. DESIGN: Two cross-sectional surveys conducted in 1980 and 1995. SUBJECTS: The samples selected for the 1980 and 1995 surveys comprised 1553 and 701 male children, and 1311 and 659 female children, respectively, with ages ranging from 6.0 to 14.9 y. MEASUREMENTS: We measured four skinfold thicknesses (biceps, triceps, subscapular, suprailiac) and calculated some indices of fat patterning: triceps/subscapular skinfolds (T/SS), biceps+triceps/subscapular+suprailiac skinfolds (B+T/SS+SI), and (subscapular+suprailiac/biceps+triceps+subscapular+suprailiac skinfolds)x100 (trunk-to-total skinfolds %). RESULTS: In males, B+T/SS+SI, and trunk-to-total skinfolds % showed a significant trend to a central pattern of fat distribution from 1980 to 1995, at the ages of 6.5-11.5 y. In females, B+T/SS+SI and trunk-to-total skinfolds % showed a significant trend to a central pattern of fat distribution from 1980 to 1995, at the ages of 6.5 and 7.5 y. Similar results were obtained when we adjusted for BMI values. CONCLUSION: We have observed a trend to a central pattern of adipose tissue distribution, especially in males and at the youngest ages studied (6-11 y in males, and 6-7 y in females). These observations were independent of trends in BMI.

Adipose Tissue↗
PubMed2001

Body mass index, triceps skinfold and waist circumference in screening for adiposity in male children and adolescents.

UNLABELLED: Simple anthropometric measurements and indices are the most commonly used tools for assessing body composition. Only a few papers have examined the sensitivity and specificity of the body mass index (BMI) against total body fat percentage (TBF%) from underwater weighing in children and adolescents. The objective of the study was to evaluate the screening performance of BMI, triceps skinfold thickness and waist circumference for excess TBF%. A total of 175 healthy volunteer males, aged 7.0-16.9 y, participated in the study. TBF% was measured using underwater weighing as the reference method. Receiver operating characteristic (ROC) curves were constructed to assess the value of the three anthropometric measurements as a screening measure for total adiposity. Sensitivity and specificity were calculated at several percentile cut-offs for BMI, triceps skinfold and waist circumference. The areas under the ROC curves were also calculated, and were 0.86 for BMI, 0.90 for triceps skinfold and 0.88 for waist circumference. The point on the ROC curve closest to 1 corresponded to the 70th percentile for BMI, to the 75th percentile for triceps skinfold, and to the 70th percentile for waist circumference. CONCLUSION: BMI, triceps skinfold and waist circumference predicted total fat content well in male children and adolescents.

Adolescent↗
PubMed2001

Postprandial triglyceridemia in obese and non-obese adolescents. Importance of body composition and fat distribution.

BACKGROUND: It has recently been shown that obese adults have a disturbed metabolism of postprandial lipoproteins, resulting in postprandial hypertriglyceridemia. To the best of our knowledge, there are no data about postprandial triglyceridemia in obese and non-obese children and adolescents. SUBJECTS: 12 obese and 12 non-obese adolescents, aged 11.0 to 13.8 years. METHODS: Body composition and fat distribution (waist-to-hip circumference ratio and triceps/ subscapular skinfold thickness ratio) were assessed by anthropometry. An oral fat tolerance test was carried out, and fasting and postprandial lipid-lipoprotein serum concentrations were measured. RESULTS: We observed a significant increase in triglyceride serum concentrations 2 and 4 hours after the oral fat load, in both obese and non-obese adolescents. In obese and non-obese adolescents there were significant correlations between some variables of postprandial lipemia and the studied indices of body fat distribution. When we compare postprandial lipemia in adolescents having a central pattern of fat distribution with those having a peripheral pattern of fat distribution, we observed higher variables related to postprandial lipemia in those having a central pattern of fat distribution compared with those with a peripheral pattern (sum of serum triglyceride concentrations: 6.06 vs 4.41, p = 0.0243). CONCLUSIONS: We present a protocol to study postprandial lipemia in children and adolescents that allowed us to observe significant changes after an oral fat load. Results obtained indicate that the pattern of distribution of adipose tissue may be more important for lipid metabolism disturbances than total adipose tissue per se.

Adipose Tissue↗
PubMed2000

Trends in body mass index and overweight prevalence among children and adolescents in the region of Aragón (Spain) from 1985 to 1995.

OBJECTIVE: To analyse trends in body mass index (BMI) and overweight prevalence for children and adolescents in the region of Aragón (Spain), from 1985 to 1995. DESIGN: Nine cross-sectional examinations of schoolchildren conducted yearly from 1985 to 1995. SUBJECTS: A total of 90,997 children (45,970 males and 45,027 females) in the first school year (6-7 y of age); 106,284 scholars (52,772 males and 53,512 females) in the last school year (13-14 y of age). MEASUREMENTS: Heights and weights were measured and BMI (kg/m2) was calculated. RESULTS: We observed a trend to higher BMI values across the surveys, by sex and age. The secular trends in BMI showed the largest increases at the upper ends of the distribution, especially in males. In children in the first school year, prevalences of overweight were higher in females than in males (P<0. 001); however, in adolescents in the last school year, prevalences were higher in males than in females (P<0.001). We observed a significant trend in overweight prevalence from 1985 to 1995 in children from the first school year (P=0.0183, in males and P=0.0168, in females). In children in the last school year there was only a significant trend in males (P<0.0001). CONCLUSION: Significant changes in BMI occurred in the population studied during the period 1985-1995, but these changes differ by age and sex. The increasing skewness of BMI in the upper percentiles of the population, especially in boys, suggests that, not only is the pediatric population getting fatter, but the fatter members are becoming more obese. Our results also show a striking increase in the prevalence of overweight children in the region of Aragón (Spain) during the 1985-1995 decade.

Adolescent↗
PubMed2000

Assessment of nutritional status and body composition in children using physical anthropometry and bioelectrical impedance: influence of diurnal variations.

BACKGROUND: To observe whether there are diurnal variations when assessing children's body composition, using physical anthropometric and bioelectrical impedance (BI) methods. METHODS: In 32 children (18 females and 14 males) aged between 7.1 and 14.9 years, weight, height, arm circumference (AC), four skinfolds, and total body impedance (Z) were measured at 8 A.M., 12 noon, 4 P.M., and 8 P.M. on the same day. Body mass index (BMI), skinfolds sum (SS), total body water (TBW), fat-free mass (FFM), and fat mass (FM) were also calculated at these times. RESULTS: Height at 8 P.M. was 1.156 +/- 0.54 cm less than at 8 A.M. (P < 0.001) and BMI increased 0.434 +/- 0.29 kg/m2 at 8 P.M. (P < 0.001). Weight, SS and AC underwent no significant changes in the course of the day. Z was 5.83% less at 8 P.M. than at 8 A.M. (P < 0.001), yielding a TBW and FFM increase at 8 P.M. of 0.855 +/- 1.061 and 1.173 +/- 1.47 kg, respectively (P < 0.001). CONCLUSIONS: In children there is a diurnal decrease in height, impedance and FM, and an increase in BMI, TBW, and FFM. These factors must be taken into account when using such methods for assessing nutritional status in childhood.

Adipose Tissue↗
PubMed1999

Waist circumference values in Spanish children--gender related differences.

OBJECTIVE: To obtain reference values of the waist circumference in Spanish children, and to investigate their dependence on age and gender. DESIGN: Cross-sectional study. SETTING: General school-age population. SUBJECTS: A representative sample of the schools in Zaragoza, Spain, was drawn from seven schools. The population selected comprised 1728 children with ages ranging from 6.0-14.9y. Of the original sample, 368 children (21.29%) were excluded because of chronic diseases or refusal. Finally, 1360 children and adolescents: 701 boys and 659 girls, were studied. INTERVENTIONS: Waist and hip circumferences were measured with an unelastic tape. RESULTS: Waist circumference tended to be higher in males than in females and this difference was significant after 11.5y. In general, hip circumference was higher in females than in males (statistically significant differences at 7.5, 10.5, 12.5 and 13.5 y). In general, percentile values of waist circumference were higher in males than in females, especially after 12.5 y. Difference between males and females on percentile 95 at 14.5 y was 7.6 cm. Hip was greater than waist in both sexes, and the two curves run nearly parallel in males. In females, while hip enlarges continuously, waist shows the reverse tendency between 11.5 and 14.5 y. CONCLUSIONS: Waist circumference showed higher values in boys than in girls, especially after 11.5 y, and waist values increase with age both in males and females. These findings justify the use of age and gender specific reference standards.

Abdomen↗