M.I. Mesana

Overweight, obesity and body fat composition in spanish adolescents. The AVENA Study.

Objective: To describe the prevalence of overweight and obesity in the Spanish adolescent population and its relationship with the socioeconomic status, and to assess their body fat composition and compare these results with previous data from our own country. Design: Cross-sectional multicenter study conducted in five Spanish cities (Granada, Madrid, Murcia, Santander and Zaragoza) in 2000–2002. Subjects: 2,320 adolescents with complete set of anthropometric measurements, 1,192 boys and 1,128 girls. Measurements: Body mass index calculated from weight and height measurements, and body fat percentage calculated from skinfold thickness measurements. Results: Overweight + obesity prevalences were 25.69 and 19.13% in boys and girls, respectively. Overweight + obesity prevalence increased in boys from high to medium-low socioeconomic status categories (p = 0.015); meanwhile, there was not a significant effect of socioeconomic status in girls. In males, overweight + obesity prevalence changed from 1985 to 2000–2002 from 13 to 35% and in females from 16 to 32%. The rate of change in overweight + obesity prevalences seems to increase in the last years; from 0.88 (1985 to 1995) to 2.33%/year (1995 to 2000–2002) in males and from 0.5 (1985 to 1995) to 1.83%/year (1995 to 2000–2002) in females. The rate of body fat percentage increase was similar between 1980 and 1995 and between 1995 and 2000–2002: 0.26 and 0.23%/year, respectively, at 13 years of age, and 0.16 and 0.17%/year, respectively, at 14 years of age. Conclusion: We observed elevated overweight and obesity prevalences in Spanish adolescents, similar to those observed in other European countries. There is a significant inverse relationship between socioeconomic status and overweight + obesity, but only in boys. The rate of change in overweight prevalence in Spanish adolescents seems to increase, and the rate of increase of body fat percentage seems to be similar as in previous years.

Harmonization of Anthropometric Measurements for a Multicenter Nutrition Survey in Spanish Adolescents

OBJECTIVE Although the need for accurate anthropometric measurement has been repeatedly stressed, reports on growth and physical measurements in human populations rarely include estimates of measurement error. We describe the standardization process and reliability of anthropometric measurements carried out in a pilot study. METHODS For the intraobserver assessment of anthropometric measurements, we studied 101 adolescents (58 boys and 43 girls) from five cities. For interobserver assessment, we studied 10 adolescents from the same class in Zaragoza and different from those in the intraobserver sample. RESULTS For skinfold thickness, intraobserver technical errors of measurement (TEMs) in general were smaller than 1 mm; for circumferences, TEMs in general were smaller than 1 cm. Intraobserver reliability for skinfold thickness was greater than 95% for almost all cases; for circumferences, intraobserver reliability generally was greater than 95%. Interobserver TEMs ranged from 1 to 2 mm for the six skinfold thicknesses measured; for circumferences, TEMs were smaller than 1 cm for the arm, biceps, and waist and between 1 and 2 cm for the hip and thigh. Interobserver reliabilities for skinfold thickness and circumference were always greater than 90%, except for biceps skinfold. CONCLUSIONS Our results are in agreement with those recommended in the literature. Therefore, these anthropometric measures seem to be adequate to assess body composition in a multicenter survey in adolescents.

Quality assurance of ethical issues and regulatory aspects relating to good clinical practices in the HELENA Cross-Sectional Study

Rationale:Research involving humans is regulated by regulatory authorities through their specific requirements and controls. The Healthy Life Style in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS) is a multicenter biomedical research study of adolescents in several representative European cities, which requires satisfying medico-regulatory requirements including Independent Ethics Committee (IEC) approval and agreement by the national or local regulatory authorities. To achieve a high level of quality assurance relating to ethical issues, we followed the good clinical practices (GCP) described at the International Conference on Harmonisation (ICH), which we adapted to the national and local situations of each of the 11 participating cities in 10 European countries.Objective:The main objective of the HELENA-CSS is to evaluate reliable and comparable data of nutritional habits and lifestyle in a representative sample of European adolescents. The aim of this paper is to present the methods relating to the ethical and regulatory issues of this study and to describe the current state of the medico-regulatory requirements involved in conducting this kind of study in each country.Materials and Methods:Following the GCP–ICH guidelines, a protocol describing the HELENA-CSS was written and approved by all partners. In the pilot study, a case report form adapted to the study objectives and its manual of operation was constructed and used by all partners. All information letters to adolescents and their parents and consent forms were first written in English, then translated into the local language, and adapted to each local situation. All documents were then checked centrally for any deviation and corrected if required. An operation manual relating to ethical issues and other medico-regulatory requirements was also developed. This paper presents the current status of the medico-regulatory requirements from each HELENA-CSS participant country.Results:Before the beginning of the study, most centers had satisfied the medico-regulatory requirements of IEC approval and agreement with other national or local regulatory authorities/organizations. For a few centers, some problems were detected and corrective actions were taken to improve missing information to reach a high level of quality assurance of ethical issues.Conclusion:The GCP–ICH guidelines about nontherapeutic biomedical research are interpreted and applied differently across Europe. This study shows that high-quality nontherapeutic biomedical research can address the ethical issues included in the GCP–ICH regulations and can be harmonized among the HELENA European partners.

Body fat distribution reference standards in Spanish adolescents: the AVENA Study

Objective:To present body fat patterning reference standards to identify children with a predominant distribution of body fat in the abdominal or truncal region of the body.Design:Cross-sectional study in a representative sample of Spanish adolescents aged 13–18 years.Subjects:A total of 2160 adolescents with a complete set of anthropometric measurements (1109 males and 1051 females).Measurements:Weight, height, body mass index, skinfold thickness (biceps, triceps, subscapular, suprailiac, thigh, calf) and waist and hip circumferences.Results:In the majority of the age groups, subscapular/triceps skinfolds ratio, trunk-to-total skinfolds percent (TTS%)and waist circumference values were significantly higher in males than in females; hip circumference was higher in females than in males, except at 15.5 years. In males, age showed a significant effect for all the body fat distribution indices; however, in females, the effect was only significant for triceps skinfold, waist and hip circumferences and waist-to-hip ratio. Smoothed age- and sex-specific triceps skinfold, subscapular skinfold, subscapular/triceps skinfolds ratio, TTS%, waist circumference and hip circumference, waist-to-hip and waist-to-height ratio percentile values for male and female adolescents have been established.Conclusion:These reference data for waist circumference and the other fat patterning indices, together with data from other countries, will help to establish international central obesity criteria for adolescents. The presented percentile values will give the possibility to estimate the proportion of adolescents with high or low regional adiposity amounts.

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 (∑6 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, ∑6 skinfolds and BF% with the formulas described by Slaughter et al.Results:∑6 skinfolds and BF% in each age group were significantly higher in females than in males. In males, age showed a significant effect for BMI, ∑6 skinfolds and BF%; however, in females, the effect was only significant for BF%. The percentile distribution was more disperse towards higher ∑6 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).

Secular trends in health-related physical fitness in Spanish adolescents: The AVENA and HELENA Studies

We analysed the secular trends in health-related physical fitness in Spanish adolescents between 2001-2002 and 2006-2007. Two representative population studies were conducted 5 years apart in adolescents (12.5-17.5 years) from Zaragoza (Spain) that participated in the AVENA study in 2001-2002 and in the HELENA-CSS study in 2006-2007. Both studies used the same tests to assess physical fitness: the handgrip strength, bent arm hang, standing broad jump, 4×10m shuttle run and 20m shuttle run tests. Performance in 4×10m shuttle run and 20m shuttle run tests was higher in 2006-2007 (Cohens d ranging from 0.2 to 0.4, p<0.05), whereas performance in handgrip strength and standing broad jump tests was lower in 2006-2007 (Cohens d ranging from 0.3 to 1.1, p<0.001). Adjustment for age, pubertal status, fat mass, fat free mass and parental education did not alter the results. The odds ratio (OR) of meeting the FITNESSGRAM Standards for healthy cardiorespiratory fitness was higher in 2006-2007 in both boys (OR, 95% CI: 2.123, 1.157-3.908) and girls (OR, 95% CI: 2.420, 1.377-4.255). The results indicate that levels of both speed/agility and cardiorespiratory fitness were higher in 2006-2007 than in 2001-2002, whereas muscular strength components were lower in 2006-2007.

How to measure dietary intake and food habits in adolescence: the European perspective

AIM:This paper deals with some methodological aspects of data collection in the context of measuring dietary intake in individuals in their adolescence life stage.METHOD:Experiences from three partners of the HELENA project in dietary intake measurement in children and adolescents are presented in this paper with emphasis on characteristics of under-reporting, long-term diet measurement and food patterns (Dortmund DONALD group), influences of survey duration on under-reporting (Ghent group) and meal habits (Spanish AVENA group).RESULTS:Under-reporters in the DONALD Study, particularly female adolescents, had a significantly higher body mass index (BMI) than non-under-reporters; BMI could not be explained by different long-term dietary patterns during childhood and adolescence clustered according to fat consumption; consumers of fast food had higher BMI values than nonconsumers. In the Ghent experience, the decline in population mean energy intake as calculated over selected clusters of days is 184 kcal (6.5%) in boys and 116 (5.6%) in girls; the cluster of 1 recording day and the cluster of 3 recording days were not significantly different but they were both significantly different from the 7-day cluster; no significant interaction was observed between the effect of time and BMI. In the AVENA Study, the percentage of adolescents skipping breakfast was higher in females (8.6%) than in males (3.5%, P<0.001); higher BMI values were observed in those skipping breakfast than in those notskipping breakfast, but differences were statistically significant in males at 15 y and in females at 14 and 17 y; adolescents avoiding some food groups for breakfast had higher BMI values (carbohydrates, fruits and pastries in males and milk, fruits and pastries in females).CONCLUSION:Dietary and nutrient intake data in the HELENA project will be obtained by means of repeated 24-h dietary recalls. Data from HELENA might be a basis for developing complex approaches like Healthy Eating Indices.

Food and drink intake during television viewing in adolescents: the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study.

OBJECTIVE To compare food consumption during television (TV) viewing among adolescents who watched >2 h/d v. ≤2 h/d; and to examine the association between sociodemographic variables (age, gender and socio-economic status (SES)) and the consumption of energy-dense foods and drinks during TV viewing. DESIGN The data are part of the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) cross-sectional survey. Data on time watching TV, types of foods and drinks consuming during TV viewing and parental SES (parental education, parental occupation and family affluence) were measured by questionnaires completed by adolescents. Binary logistic regression tested the association between energy-dense foods and drinks and (i) sociodemographic variables and (ii) TV time. SETTING Ghent (Belgium), Heraklion (Greece), Pecs (Hungary) and Zaragoza (Spain). SUBJECTS Girls (n 699) and boys (n 637) aged 12·5-17·5 years. RESULTS Boys reported more frequent consumption of beer and soft drinks whereas girls selected more fruit juice, water, herbal infusions and sweets (all P ≤ 0·05). Watching TV for >2 h/d was associated with the consumption of energy-dense foods and drinks. Girls whose mothers achieved the lowest education level had an adjusted OR of 3·22 (95 % CI 1·81, 5·72) for the consumption of energy-dense drinks during TV viewing v. those whose mothers had the highest educational level. CONCLUSIONS Excessive TV watching may favour concurrent consumption of energy-dense snacks and beverages. Adolescents from low-SES families are more likely to consume unhealthy drinks while watching TV.

Physical fitness effect on bone mass is mediated by the independent association between lean mass and bone mass through adolescence: a cross-sectional study

We studied 278 adolescents (169 females) aged 13.0–18.5 years to elucidate whether an independent effect of physical fitness and lean mass in the differences between male and female bones can be detected. Lean and fat masses and bone mineral content (BMC) were measured with DXA. Physical fitness was evaluated with six different tests included in the EUROFIT test battery (flexibility, isometric, dynamic and endurance strength, speed, and cardiovascular fitness). To test the independent relationship between physical fitness and bone mass, multiple regression analysis was applied, including lean mass, age, and Tanner development as covariates. The males had a 43% lower fat mass and 40% and 16% higher lean mass and total BMC compared with the females (all P < 0.05). After adjustment for differences in body size and lean mass, the females exhibited a 7.4% higher BMC than the males (P < 0.05). The multiple regression analysis showed that lean mass had an independent relationship with bone mass (P < 0.001), explaining 67% of the total variance in whole-body BMC. In males, change in R2 was 0.658 for hand grip and 0.035–0.151 for the rest of physical fitness-related variables; but 0.019–0.042 in females (all P–0.001); however, the independent relationships between physical fitness and bone disappeared after controlling for lean mass. In conclusion, it is likely the differences between male and female in bone mass could be explained by differences in lean mass and physical fitness.

Independent and combined effect of nutrition and exercise on bone mass development.

Food intake provides the necessary components for adequate metabolic functions in bone. Calcium, phosphorus, vitamin D, magnesium, proteins, and fluoride are some of the most important nutrients in this regard. These have different effects on bone mass. Additionally, exercise has been shown to elicit osteogenic responses in bone development; indeed, it seems to potentiate, for example, the effect of calcium supplementation on bone mass. However, the nutrition-exercise-bone mass relationship is complex and needs further in-depth investigation. As a first step, therefore, we reviewed current knowledge about the role of nutrition on the development of bone tissue and how physical activity affects the nutrient-bone relationship.