Nutritional status and lifestyles of adolescents from a public health perspective. The HELENA Project—Healthy Lifestyle in Europe by Nutrition in Adolescence

New indices in predicting cardiometabolic risk and its relation to endothelial dysfunction in adolescents: The HELENA study

BACKGROUND AND AIMS

Blood pressure (BP) changes and insulin resistance (IR) are important cardiometabolic risk (CMR) factors; their early identification can contribute to the reduction of cardiovascular events in adulthood. This necessitates the search for more accessible and easily applied indicators for their prediction. Therefore, this study aimed to evaluate the predictive power of the indices, TyG, TG/HDL-c, height-corrected lipid accumulation product (HLAP), and visceral adiposity index (VAI), in identifying the CMR obtained by high BP and IR and to verify their relationship with biomarkers of endothelial dysfunction (ED) in European adolescents.

METHODS AND RESULTS

The anthropometric data and blood biomarkers of 744 adolescents (343 boys and 401 girls) from the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS), with a mean age of 14.67 (SD 1.15) years, were assessed. The adolescents were then classified according to the presence or absence of high BP and IR. The cut-off points of the indices evaluated for the identification of CMR were determined. The relationship between CMR diagnosed using these indices and ED biomarkers was tested. The HLAP and TG/HDL-c were fair predictors of CMR obtained by IR in male adolescents. These indices showed association with hsCRP in sVCAM-1 in boys, but it lost significance after adjusting for age and body mass index.

CONCLUSION

TG/HDL-c and HLAP indices showed a fair performance in predicting CMR, obtained by IR, in male adolescents. ED showed no association with the CMR identified by the indices.

Food portion sizes and their relationship with energy, and nutrient intakes in adolescents: The HELENA study

OBJECTIVES

This study aimed to investigate the associations between portion sizes (PSs) from different food groups and energy, as well as nutrient intakes in European adolescents.

METHODS

A sample of 1631 adolescents (54.2 % girls) were included from the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional (HELENA) study. Mean food PS was calculated by dividing the total intake of the items by the number of eating occasions of these consumed items. To determine the key items for analysis, foods were ranked by frequency of consumption. A one-way between-groups analysis of covariance was used to test for significant differences in means across tertiles. A multivariable linear regression analysis was carried out, adjusting for age, sex, maternal education, body mass index, and using country as a level.

RESULTS

Energy intake increased with elevated intakes of energy-dense foods. Large portions of rice and other grains, starch roots and potatoes, and meat substitutes, nuts, and pulses were associated with increased carbohydrate and fiber intake. Larger portions of cheese and butter and animal fat were significantly associated with a higher fat intake. Lower intakes of some vitamins and micronutrients were noticed with consumption of larger portions of high energy-dense foods, such as desserts and pudding, margarine and vegetable oil, and butter and animal fat.

CONCLUSIONS

Large food PSs may be associated with positive energy, as well as macro- and micronutrient intake. Moreover, the findings from this study may help the future development of dietary guidance in general and specific to PSs, and support targeted strategies to address intakes of certain nutrients in European adolescents.

Associations between food portion sizes, insulin resistance, VO2 max and metabolic syndrome in European adolescents: The HELENA study

BACKGROUND AND AIMS

This study aims to examine the associations of food portion size (PS) with markers of insulin resistance (IR) and clustered of metabolic risk score in European adolescents.

METHODS

A total of 495 adolescents (53.5% females) from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study were included. The association between PS from food groups and homeostasis model assessment of insulin resistance (HOMA-IR) index, VO2 max, and metabolic risk score was assessed by multilinear regression analysis adjusting for several confounders. Analysis of covariance (ANCOVA) was used to determine the mean differences of food PS from food groups by HOMA-IR cutoff categories by using maternal education as a covariable.

RESULTS

Larger PS from vegetables in both gender and milk, yoghurt, and milk beverages in males were associated with higher VO2 max, while larger PS from margarines and vegetable oils were associated with lower VO2 max (p < 0.05). Males who consumed larger PS from fish and fish products; meat substitutes, nuts, and pulses; cakes, pies, and biscuits; and sugar, honey, jams, and chocolate have a higher metabolic risk score (p < 0.05). Males with lower HOMA-IR cutoff values consumed larger PS from vegetables, milk, yoghurt, and milk beverages (p < 0.05). Females with lower HOMA-IR cutoff values consumed larger PS from breakfast cereals, while those with higher HOMA-IR cutoff values consumed larger PS from butter and animal fats (p = 0.018).

CONCLUSION

The results show that larger PS from dairy products, cereals, and high energy dense foods are a significant determinant of IR and VO2 max, and larger PS from food with higher content of sugar were associated with higher metabolic risk score.

Breakfast Dietary Pattern Is Inversely Associated with Overweight/Obesity in European Adolescents: The HELENA Study

Obesity in children and adolescents is a public health problem and diet can play a major role in this condition. We aimed to identify sex-specific dietary patterns (DP) and to evaluate the association with overweight/obesity in European adolescents. We conducted a cross-sectional analysis with 2327 adolescents aged between 12.5 to 17.5 years from a multicenter study across Europe. The body mass index was categorized in “normal weight” and “overweight/obesity”. Two non-consecutive 24-h dietary recalls were collected with a computerized self-reported software. Principal component factor analysis was used to identify DP. Mixed-effect logistic regression models were used to evaluate the association between the sex-specific DP and overweight/obesity outcome. As a result, we found three DP in boys (snacking and bread, Mediterranean diet, and breakfast) and four DP in girls (convenience, plant-based and eggs, Western, and breakfast). The association between DP and overweight/obesity highlights that those adolescents with higher adherence to the breakfast DP had lower odds for overweight/obesity, even after the inclusion of covariables in the adjustments. In European adolescents, the breakfast DP positively characterized by breakfast cereals, fruit, milk, and dairy and negatively characterized by sugar-sweetened beverages in boys and negatively characterized by cereals (pasta, rice, and others) in girls, was inversely associated with overweight/obesity.

The Association between Portion Sizes from High-Energy-Dense Foods and Body Composition in European Adolescents: The HELENA Study

Obesity prevalence has been simultaneously increasing with high consumption of large food portion sizes (PS). However, there is scarce information on PS of energy-dense (ED) foods as a potential risk factor of obesity in adolescents. In the present study, we investigate the association between the PS of the most ED foods and body composition. A sample of 1889 adolescents (54.4% females) from the Healthy Lifestyle in Europe by Nutrition in Adolescence cross-sectional multicenter study (HELENA-CSS) study were included. Most ED foods (e.g., cheese) were selected according to higher fat and/or sugar content and low fiber and water. Linear and ordinal logistic regression models were adjusted for age, physical activity, total energy intake (TEI), and socioeconomic status (SES). Analysis was performed both in those adolescents reporting plausible energy intake according to the approach of Goldberg et al. and in the whole sample. In male plausible reporters, PS from "breakfast cereals" showed a significant and positive association with BMI (β = 0.012; 0.048). PS from "carbonated soft drinks" in males (OR = 1.001; 95% CI 1.000; 1.002) and "bread and rolls" in females (OR = 1.002; 95% CI 1.000; 1.004) were associated with higher probability of having obesity, while "sweet bakery products" were associated with lower probability of having obesity (OR = 0.996; 95% CI 0.991; 0.999) in females. The present study suggests association between PS of ED foods and obesity in European adolescents. Prospective studies are needed to examine the effect of prolonged exposure to large PS and obesity development.

Free Sugar Consumption and Obesity in European Adolescents: The HELENA Study

Few studies have evaluated the association between dietary free sugars intake (FSI) and obesity in adolescents. We examined the relation between FSI and their contributors from the main food groups and obesity in European adolescents. We included 843 adolescents (51.6% male) from the cross-sectional HELENA study with two completed 24 h recalls and anthropometric data. Linear mixed models were applied to investigate the relation between FSI and different anthropometric indices. Odds ratios for having a high body mass index (BMI) were also estimated by multilevel ordinal regression. Total FSI was higher in males than females (102.60 g and 87.58 g, respectively, p < 0.001). No effect was observed between free sugar from the main food groups and BMI. Consumers of FSI from "cakes, pies and biscuits" in males (odd ratio (OR) = 0.455; 95% Confidence interval (CI) 0.251, 0.824) and from "breakfast cereals" in females had a lower probability of having obesity (OR = 0.423; 95%CI 0.204, 0.878), whereas females consuming FSI from 'fruit and vegetables juices' had a higher probability of obesity (OR= 2.733; 95% CI 1.286, 5.810). This study provides no evidence that increased FSI is associated with obesity in adolescents. Further studies are needed to assess the longitudinal exposure to FSI and their effect on obesity development.

Health-Related Factors in Rural and Urban Mexican Adolescents from the State of Jalisco: The HELENA-MEX Study

Mexico shows a high prevalence of obesity in children and adolescents. Geographical location and cultural environment could play a role in the promotion of healthy lifestyles in terms of physical activity (PA), sedentary behavior (SB) and nutrition. The purpose of this study was to assess rural and urban differences in body composition (BC), physical fitness (PF), PA and nutritional status of adolescents from the state of Jalisco (Mexico). The study involved 469 students aged 13–17 years (55.0% girls) from eight high schools. BC was analyzed by bioimpedance and PF by standardized field tests. Objective measurements of PA and SB were taken in a subsample (n = 240). Energy intake (EI) was calculated from two 24h recalls. Rural residents presented a higher prevalence of overweight, waist circumference, trunk fat mass, regional fat free mass and muscle handgrip strength (all p < 0.05, η2p < 0.06). Cardiorespiratory fitness was similar among participants, whereas urban adolescents showed higher muscle power, speed-agility and flexibility scores (all p < 0.05, η2p < 0.07). Overall lifestyle behavior in urban adolescents was more sedentary (p < 0.05, η2p = 0.11). EI was similar in both locations. In conclusion, rural Mexican adolescents presented a generally lower sedentary behavior and a lower fitness and fatness profile than their urban peers.

Evaluation of nutritional status of foreign students at King Saud University, Kingdom of Saudi Arabia

OBJECTIVE

The current study was conducted to assess the nutritional status and associated risk factors among foreign students residing at King Saud University for different periods and to explore its correlations.

DESIGN

A cross-sectional study was conducted during the spring semester of 2018. A total of 400 male students aged 18-35 years had participated in the current study after signing a written consent form according to Helsinki Declaration.

SETTING

A structural questionnaire was used to collect data on daily food intake and habits and socio-economic characteristics. Nutrients of food intake were assessed using the Esha programme and compared with that of dietary requirement intake (DRI). A body composition analyser was used to measure body fat (BF), visceral fat (VF) and BMI. Spearman correlation coefficients and simple regression analysis were performed to determine associations between variables.

PARTICIPANTS

Foreign students residing for different periods (<6 months: 200 students and >6 months: 200 students) were used as subjects.

RESULTS

The students who stayed <6 months consumed lower level of some nutrients than that of the DRI compared with those stayed >6 months. Overweight and obesity were more common among students who stayed >6 months with high values of BF and VF. Several risk factors were positively or negatively correlated with the students' nutrition proxies.

CONCLUSION

Most of the students who stayed >6 months are suffered from overweight. Some independent variables were found to be significantly correlated with the students' nutrition proxies either positively or negatively.

Gym Members Show Lower Nutrition Knowledge than Youth Engaged in Competitive Sports

OBJECTIVE

Adolescents may be vulnerable to misleading nutritional information and adopt unhealthy food habits. In addition, specific features related to physical training, either aimed to improve fitness or to comply with sport demands, may influence food habits of the youth. This cross-sectional study was aimed to compare nutrition knowledge, food habits and adherence to Mediterranean diet in youth engaged in fitness training, competitive sports or inactive.

METHODS

Three questionnaires, the General and Sport Nutrition Knowledge (GeSNK) questionnaire, a food habit questionnaire and the KIDMED were administered to gym members, athletes engaged in volleyball, long-distance swimming, and gymnastics, and inactive adolescents.

RESULTS

The total sample included 211 youth (age 16.8 ± 1.7 years). Gym members, like the inactive youth, had lower general and sport-related nutrition knowledge compared to athletes (p = 0.001). In the whole sample, general nutrition knowledge was positively associated with healthy food habits (p < 0.01) and adherence to the Mediterranean diet pattern (p < 0.02).

CONCLUSIONS

Gym members had a level of nutrition knowledge lower than young athletes and similar to inactive youth. Healthy food habits were related with nutrition knowledge among adolescents. Specific nutritional education programs are needed to address food habits in fitness settings.

Dietary sources of sugars in adolescents' diet: the HELENA study

OBJECTIVE

To report dietary sugars consumption and their different types and food sources, in European adolescents.

METHODS

Food consumption data of selected groups were obtained from 1630 adolescents (45.6% males, 12.5-17.5 years) from the HELENA study using two nonconsecutive 24-h recalls. Energy intake, total sugars and free sugars were assessed using the HELENA-DIAT software. Multiple regression analyses were performed adjusting for relevant confounders.

RESULTS

Total sugars intake (137.5 g/day) represented 23.6% and free sugars (110.1 g/day), 19% of energy intake. Girls had significantly lower intakes of energy, carbohydrates, total sugars and free sugars. 94% of adolescents had a consumption of free sugars above 10% of total energy intake. The main food contributor to free sugars was 'carbonated, soft and isotonic drinks,' followed by 'non-chocolate confectionary' and 'sugar, honey, jam and syrup.' Older boys and girls had significantly higher intakes of free sugars from 'cakes, pies and biscuits.' Free sugars intake was negatively associated with low socioeconomic status for 'non-chocolate confectionary' and 'sugar, honey and jam' groups; with low maternal educational level for carbonated and 'soft drinks,' 'sugar, honey and jam,' 'cakes and pies' and 'breakfast cereals' groups; and with high paternal educational level for 'carbonated and soft drinks' and 'chocolates' group.

CONCLUSIONS

The majority (94%) of studied adolescents consumed free sugars above 10% of daily energy intake. Our data indicate a broad variety in foods providing free sugars. Continued efforts are required at different levels to reduce the intake of free sugars, especially in families with a low educational level.

[Dietary habits of adolescents and associated cardiovascular risk factors: a systematic review]

The scope of this study was to conduct a systematic review to establish the major dietary habits of adolescents and the corresponding association with cardiovascular risk factors. Research was performed in the LILACS, SciELO, PubMed, Scopus and Web of Science databases in addition to a manual search for original articles published between 2005 and 2014. Of the 371 entries identified; 26 fulfilled the inclusion criteria and were covered in the review. The main dietary habits observed were Western (61%) Healthy (42%) and Traditional (38%). Western dietary habits were positively associated with total cholesterol and SM, while Healthy dietary habits were inversely associated with fasting glycaemia, DBP and SM and positively with HDL-C, all of the aforementioned associations with very low (D) quality of evidence in accordance with the GRADE rating. The Traditional dietary habits were considered a risk factor for hyperglycemia, hyperinsulinemia and hypertriglyceridemia and protection for physical activity and eutrophic BMI. Although these results need to be analyzed with caution, due to the low quality of evidence, there is a clear need for actions aimed at promoting healthy dietary habits in adolescents in order to contribute to the prevention of cardiovascular risk factors.

Dietary intake of adolescents compared with the Brazilian Food Guide and their differences according to anthropometric data and physical activity

OBJECTIVE

To assess the dietary intake of adolescents compared with the Brazilian Food Guide and to explore their differences according to anthropometric data and physical activity.

METHODS

A total of 476 adolescents from public schools of Piracicaba, SP, Brazil participated in this study. A semi-quantitative food frequency questionnaire was used to estimate food group intake of adolescents. Height, weight and waist circumference of all participants were measured. Physical activity pattern was determined by questioning about participation in regular sport activities.

RESULTS

The prevalence of overweight was 36.1% and 60% were not physically active. 7.8, 7.1, 6.3, and 0.2% of adolescents consumed vegetables, fruits, milk and derivatives, and cereals, respectively, according to recommendations. About 55 and 79% of adolescents consumed excessively oils/fats and sugar/sweets, respectively. Physically active adolescents consumed more cereals, fruits, vegetables, milk and derivatives, and meats and eggs.

CONCLUSION

Most adolescents did not follow the food group recommendations and those who were physically active have healthier food habits.

Fruit and vegetables consumption is associated with higher vitamin intake and blood vitamin status among European adolescents

BACKGROUND/OBJECTIVES

Current research in adults indicates that fruit and vegetable (FAV) consumption increases serum levels of vitamins C, E and folate of β-carotene and reduces homocysteine concentrations. The aim of the present study was to examine the association of FAV consumption on vitamin intakes and their impact on blood vitamin concentrations in European adolescents.

SUBJECT/METHODS

This multi-center cross-sectional study included 702 (53.7% females) adolescents, aged 12.50-17.49 years, from 10 European cities. Two independent self-administered 24 h dietary recalls were used to estimate the adolescent's diet. The total energy, vitamins and FAV consumption were calculated. Adolescents were categorized into three groups: (i) very low FAV intake (<200 g/day); (ii) low FAV consumption (200-399 g/day) and (iii) adequate FAV consumption (⩾400 g/day). Adolescent's fasted blood samples were taken for their analysis on vitamin concentrations.

RESULTS

The main results showed that those adolescents meeting the FAV recommendation, classified as FAV adequate consumers, presented higher intake of energy and some vitamins as B6, total folic acid, C, E and β-carotene compared with FAV very low consumers (P<0.05). Regarding their blood status, male adolescents who had a very low FAV consumption presented lower plasma folate, RBC folate blood concentrations compared with adequate FAV consumers (P<0.05). Female adequate FAV consumers had higher concentrations of pyridoxal phosphate (PLP), plasma folate, RBC folate, vitamin C, β-carotene and α-tocopherol compared with very low and low consumers (P<0.05).

CONCLUSIONS

Having a FAV dairy intake above 400 g/day is associated with higher vitamin intake and blood vitamin concentrations, especially for antioxidant and B-vitamins concentrations.

Regular breakfast consumption is associated with higher blood vitamin status in adolescents: the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study

Objective

The present study aimed to examine the association between different breakfast consumption patterns and vitamin intakes and blood vitamin concentrations in European adolescents.

Design

Breakfast consumption was assessed by a questionnaire. Vitamin intake was calculated from two 24 h recalls. Blood vitamin and total homocysteine (tHcy) concentrations were analysed from fasting blood samples.

Setting

The European Commission-funded HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study.

Subjects

Participants were 1058 (52·8 % females) European adolescents (aged 12·5–17·5 years) from ten cities.

Results

Lower vitamin D and vitamin C concentrations were observed in male and female breakfast skippers than in consumers (P<0·05). Female breakfast consumers presented higher holo-transcobalamin and lower tHcy (P<0·05), while males had higher cobalamin concentrations, compared with skippers (P<0·05). Higher vitamin D and total folate intakes were observed in adolescents who consumed breakfast compared with skippers (P<0·05). Likewise, female consumers had higher intakes of vitamin B6and vitamin E than occasional consumers (P<0·05).

Conclusions

Regular breakfast consumption is associated with higher blood vitamin D and cobalamin concentrations in males and with higher vitamin D and holo-transcobalamin and lower tHcy concentrations in females. Moreover, breakfast consumption is associated with high intakes of vitamin D and total folate in both sexes, and with high intakes of vitamin B6and vitamin E in females.

Fruit and vegetable intake among college students in nitra - comparative study

The aim of the study was to collect and analyse the frequency of fruit (fresh, dried, canned and nuts) and vegetable (fresh, tinned, legumes, soya) consumption in the group of 242 respondents aged 19 - 22 years-students of Constantine the Philosopher University in Nitra; to evaluate differences according to field of study and language in which they study (Hungarian or Slovak) by questionnaire method. On the base of collected data it can be concluded that in general the consumption of fresh fruits and vegetables can be considered as very low (only once a day) together with canned and dried fruit (nuts) and tinned vegetable (rarely). Furthermore, the majority of respondents took legumes only 1 - 3 times a week or rarely and soya had never been consumed. The statistically significant differences between college students of PEEH and the rest of assayed group of students had not been confirmed so the higher level of knowledge in health has not been connected with the higher consumption of fruits and vegetables. On the other hand, statistically significant differences have been proved between the following assayed groups of university students: RTH ↔ RTS (χ 7.90, p <0.05), J ↔ RTH (χ 9.99, p <0.05), J ↔ RTS (χ 10.00, p <0.05), J ↔ PEES - SK (χ 9.91, p <0.05). Statistically significant differences were assayed also in consumption of dried fruits or nuts among the following field of study: J ↔RTS (χ 9.48, p <0.01), RTH ↔ RTS (χ 12.57, p <0.05), RTS↔PEES (χ 8.19, p <0.01). Consumption of fresh vegetables was statistically different between the students J↔RTS (χ 9.95, p <0.05) and RTS ↔PEES (χ 8.19, p <0.01).

Choice architecture interventions for increased vegetable intake and behaviour change in a school setting: a systematic review

Aims:

The primary objective of this review is to assess the prevalence and quality of published studies on the effect of choice architectural nudge interventions promoting vegetable consumption among adolescents. Additionally, this review aims to identify studies estimating adolescents’ attitude towards choice architectural nudge interventions.

Methods:

Web of Science, Scopus and PubMed were searched systematically for experimental studies with a predefined search strategy in the period November–December 2013. Publications were included following predetermined inclusion criteria. Studies were evaluated as of high, moderate or weak quality. Finally, studies were grouped by the type of intervention and underwent a narrative synthesis.

Results:

The search showed that only very few studies investigated the effects of choice architectural nudging interventions on vegetable consumption, and none of them had attitude towards behavioural interventions as an outcome measure. Twelve studies met the inclusion criteria. The results of the 12 studies were inconclusive, and the majority of studies were of weak or moderate quality.

Conclusion:

This review uncovers a gap in knowledge on the effect of choice architectural nudge interventions aiming to promote the intake of vegetables among adolescents in a school context. It also highlights that no previous studies have considered the attitudes towards choice architectural nudge interventions as a potential factor for their success – or lack thereof – in achieving the desired goal of increased vegetable consumption.

Impact of physical activity and cardiovascular fitness on total homocysteine concentrations in European adolescents: The HELENA study

We examined the association of physical activity (PA), cardiovascular fitness (CVF) and fatness with total homocysteine (tHcy) concentrations in European adolescents. The present study comprised 713 European adolescents aged 14.8 ± 1.2 y (females 55.3%) from the multicenter HELENA cross-sectional study. PA was assessed through accelerometry, CVF by the 20-m shuttle run test, and body fat by skinfold thicknesses with the Slaughter equation. Plasma folate, cobalamin, and tHcy concentrations were measured. To examine the association of tHcy with PA, CVF, and fatness after controlling for a set of confounders including age, maturity, folate, cobalamin, creatinine, smoking, supplement use, and methylenetetrahydrofolate reductase 677 genotype (CC 47%, CT 43%, TT 10%), bivariate correlations followed by multiple regression models were performed. In the bivariate correlation analysis, tHcy concentrations were slightly negatively correlated (p<0.05) with CVF in females (measured both by stages: r=-0.118 and by VO2max: r=-0.102) and positively with body mass index (r=0.100). However, daily time spent with moderate and vigorous PA showed a weak positive association with tHcy in females (p<0.05). tHcy concentrations showed a tendency to decrease with increasing CVF and increase with increasing BMI in female European adolescents. However, tHcy concentrations were positively associated with moderate and vigorous PA in female European adolescents.

Comparison of different approaches to calculate nutrient intakes based upon 24-h recall data derived from a multicenter study in European adolescents

PURPOSE

The European "Healthy Lifestyle in Europe by Nutrition in Adolescence" (HELENA) project evaluated two different approaches to harmonize the matching procedures between 24-h recall data and food composition databases. In the first approach, the 24-h recall data were linked to the local/national food composition databases using standardized procedures, while in the second approach, the 24-h recall data were linked to the German BLS database which includes a larger food list. The aim of this paper was to compare the intakes of energy and eight nutrient components calculated via both approaches.

METHODS

Two non-consecutive 24-h recalls were performed in 1268 adolescents. Energy, carbohydrates, proteins, fat, fiber, water, alcohol, calcium and vitamin C were calculated via the two approaches at individual level. Paired samples t test and Pearson's correlations were used to compare the mean intakes of energy and the eight mentioned nutrients and to investigate the possible associations between the two approaches.

RESULTS

Small but significant differences were found between the intakes of energy and the eight food components when comparing both approaches. Very strong and strong correlations (0.70-0.95) were found between both methods for all nutrients.

CONCLUSION

The dietary intakes obtained via the two different linking procedures are highly correlated for energy and the eight nutrients under study.

Dietary lipid intake only partially influences variance in serum phospholipid fatty acid composition in adolescents: impact of other dietary factors

The present study aimed to assess the correlation between food and fatty acid (FA) intake and the serum phospholipid (PL) FA status in European adolescents and explored the percentage of variation in serum PL FA that could be attributed to dietary habits. Participants included 528 adolescents recruited in the HELENA Study. Dietary intake was assessed by two, self-administered, non-consecutive 24-h recalls. PL FA concentrations were measured in fasting venous serum samples. Reduced rank regressions were applied to examine the combined effect of food intakes. Results indicated that the variance in serum PL FA in adolescents, that could be explained by diet varied from 7.0% for MUFA to 14.2% for n-3FA. The variance in the long-chain n-3FA was mainly explained by fish intake but also by coffee and tea consumption. In conclusion this study indicated that dietary intake influences the serum PL FA status to a limited amount but that also other factors interfere. However, dietary intake is important as it is among those factors that could be modified. Furthermore, the results suggest that the overall dietary habits should be considered instead of only the consumption of single foods or nutrients, as the medium of the food or concomitant intake of foods and nutrients might interact and as such influence absorption or metabolism.

Health inequalities in urban adolescents: role of physical activity, diet, and genetics

OBJECTIVE

Coordinated European projects relying on standardized methods are needed to identify health inequalities across Europe. This study aimed to compare fitness, fatness, and cardiometabolic risk between urban adolescents from the south and center-north of Europe and to explore whether physical activity (PA) and other factors might explain these differences.

METHODS

The Healthy Lifestyle in Europe by Nutrition in Adolescence cross-sectional project comprised 3528 adolescents from the south (4 cities) and central-north (6 cities) of Europe, 1089 of whom provided blood samples for analysis. Fitness (strength, speed-agility, and cardiorespiratory fitness), total and abdominal fatness (anthropometry and bioelectrical impedance), and cardiometabolic risk (z scores including fitness, fatness, blood lipids, insulin resistance, and blood pressure) were assessed. The analyses were adjusted for socioeconomic factors, objectively measured PA (accelerometry), total energy intake and diet quality, and genetic variants of the FTO rs9939609 polymorphism.

RESULTS

Adolescents from southern Europe were less fit and fatter according to all markers (P < .001). Differences in cardiometabolic risk scores were not consistent. Adolescents from the south were less active and this would largely explain the differences observed in speed-agility and cardiorespiratory fitness. Differences in total and abdominal fatness could not be explained by PA, energy intake, diet quality, or FTO rs9939609 polymorphism.

CONCLUSIONS

Fitness and fatness levels indicate that urban adolescents from the south are less healthy than those from central-northern Europe. Our data suggest that differences in PA might explain differences in important health-related fitness components, yet factors explaining the differences in fatness encountered remain unknown.

Lunch at school, at home or elsewhere. Where do adolescents usually get it and what do they eat? Results of the HELENA Study

Considering the lack of uniformity regarding school meals in Europe, information on adolescents' school lunch patterns is of public health importance. Thus, the aim of this analysis was to describe and evaluate lunchtime energy and food intake of European adolescents at different lunch locations. Data on nutritional and health-related parameters were derived from the HEalthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS). A sub-sample of 891 adolescents (47% male) with plausible data on total and lunchtime energy intake (2 × 24 h recall) as well as usual lunch location was considered. Food intake was compared to lunch of the Optimized Mixed Diet (OMD) for children and adolescents. Although energy intake was nearly in line with the recommendations, food intake was suboptimal compared to the OMD regardless of usual lunch location. Adolescents had more potatoes and less sweets at school, and more drinks (water, coffee and tea) and vegetables at home when each compared with the other locations. Food intake of adolescents getting their lunch elsewhere was characterized by the smallest amounts of potatoes and the highest amounts of sweets. Although lunch patterns may differ among countries, schools in Europe do not seem to reveal all their potential to offer access to a healthy lunch for adolescents yet.

Intake and serum profile of fatty acids are weakly correlated with global dietary quality in European adolescents

OBJECTIVE

The present study assessed whether compliance with the Food-Based Dietary Guidelines is related to habitual fatty acid (FA) intake and blood lipid parameters.

METHODS

Dietary information was collected by two non-consecutive 24-h recalls in 1804 European adolescents. Compliance with the Food-Based Dietary Guidelines was expressed by calculating the Diet Quality Index for Adolescents (DQI-A). Blood samples were collected in a randomly selected subset (n = 552). Relations between FA intake/serum concentrations and DQI-A were tested with multilevel regression analysis to correct for the study design (clustering within cities). Analyses were stratified for gender; age was entered as a covariate.

RESULTS

Better DQI-A scores were related to increased proportional intakes of energy from total fat, saturated FA, monounsaturated FA, and cholesterol (P < 0.001), whereas no significant association was observed with polyunsaturated FA intakes. In adolescents with higher compared with lower DQI-A scores, dairy products contributed more (21.0% versus 12.7%) and low-nutrient, energy-dense items contributed less (17.2% versus 26.3%) to the intake of total fat. A positive association was observed between the DQI-A scores and serum concentrations of eicosapentaenoic acid and docosahexaenoic acid (all P < 0.005). The latter, however, was significant only in girls. In boys, higher DQI-A scores were inversely associated with serum cholesterol concentrations (P < 0.05).

CONCLUSION

Although compliance with the Food-Based Dietary Guidelines was not always associated with a favorable FA intake pattern, a significant favorable association with some serum biomarkers was observed. This outcome underlines the importance of considering dietary habits instead of single-nutrient intakes.

Association between self-reported sleep duration and dietary quality in European adolescents

Evidence has grown supporting the role for short sleep duration as an independent risk factor for weight gain and obesity. The purpose of the present study was to examine the relationship between sleep duration and dietary quality in European adolescents. The sample consisted of 1522 adolescents (aged 12.5-17.5 years) participating in the European multi-centre cross-sectional ‘Healthy Lifestyle in Europe by Nutrition in Adolescence’ study. Sleep duration was estimated by a self-reported questionnaire. Dietary intake was assessed by two 24 h recalls. The Diet Quality Index for Adolescents with Meal index (DQI-AM) was used to calculate overall dietary quality, considering the components dietary equilibrium, dietary diversity, dietary quality and a meal index. An average sleep duration of ≥ 9 h was classified as optimal, between 8 and 9 h as borderline insufficient and < 8 h as insufficient. Sleep duration and the DQI-AM score were positively associated (β = 0.027, r 0.130, P< 0.001). Adolescents with insufficient (62.05 (sd 14.18)) and borderline insufficient sleep (64.25 (sd 12.87)) scored lower on the DQI-AM than adolescents with an optimal sleep duration (64.57 (sd 12.39)) (P< 0.001; P= 0.018). The present study demonstrated in European adolescents that short sleep duration was associated with a lower dietary quality. This supports the hypothesis that the health consequences of insufficient sleep may be mediated by the relationship of insufficient sleep to poor dietary quality.

Can differences in physical activity by socio-economic status in European adolescents be explained by differences in psychosocial correlates? A mediation analysis within the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study

OBJECTIVE

Socio-economic status (SES) has been positively associated with physical activity (PA) levels in adolescents. In order to tackle these social inequalities, information is needed about the underlying mechanisms of this association. The present study aimed to investigate the potential mediating role of psychosocial correlates of PA on the relationship between SES and PA in European adolescents.

DESIGN

Cross-sectional study testing the mediating role of psychosocial correlates in the SES-PA association using the product-of-coefficients test of MacKinnon.

SETTING

Ten European cities in nine different countries, the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study.

SUBJECTS

Adolescents (n 2780) aged 12·5-17·49 years self-reported on PA (moderate-to-vigorous intensity PA and total PA), SES indicators (education of the mother and Family Affluence Scale) and psychosocial correlates of PA (stage of change, attitudes, awareness, modelling, social support, self-efficacy, benefits, barriers and environmental correlates).

RESULTS

SES (Family Affluence Scale) was significantly associated with moderate-to-vigorous intensity PA. According to single-mediator models, this association was significantly mediated by stage of change (t = 3·6, P ≤ 0·001), awareness (t = 2·7, 0·001 < P ≤ 0·01), modelling (t = 4·8, P ≤ 0·001), self-efficacy (t = 2·5, 0·01

CONCLUSIONS

Adolescents with low family wealth scored lower on stage of change, awareness, modelling, self-efficacy and environmental correlates of PA, and higher on PA barriers, which in turn resulted in lower levels of moderate-to-vigorous PA. Future interventions should target these individual and environmental constructs in order to tackle and intervene on social inequalities in PA among adolescents.

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Key Words

• adolescence
• mediating effect
• europe
• family wealth

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MESH Headings

• Adolescent
• Awareness
• Child
• Cross-Sectional Studies
• Europe
• Exercise/psychology
• Female
• Health Behavior
• Humans
• Intention
• Life Style
• Male
• Self Efficacy
• Self Report
• Social Class
• Social Support
• Socioeconomic Factors

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Affiliation(s)

Katrien De Cocker Department of Movement and Sports Sciences, Ghent University, Watersportlaan 2, Ghent, Belgium.
Enrique G Artero
Stefaan De Henauw
Sabine Dietrich
Frédéric Gottrand
Laurent Béghin
Maria Hagströmer
Michael Sjöström
Maria Plada
Yannis Manios
Beatrice Mauro
Dénes Molnár
Luis A Moreno
Charlene Ottevaere
Jara Valtueña
Lea Maes
Ilse De Bourdeaudhuij

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Validation of the Diet Quality Index for Adolescents by comparison with biomarkers, nutrient and food intakes: the HELENA study

Food-based dietary guidelines (FBDG) aim to address the nutritional requirements at population level in order to prevent diseases and promote a healthy lifestyle. Diet quality indices can be used to assess the compliance with these FBDG. The present study aimed to investigate whether the newly developed Diet Quality Index for Adolescents (DQI-A) is a good surrogate measure for adherence to FBDG, and whether adherence to these FBDG effectively leads to better nutrient intakes and nutritional biomarkers in adolescents. Participants included 1804 European adolescents who were recruited in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) Study. Dietary intake was assessed by two, non-consecutive 24 h recalls. A DQI-A score, considering the components' dietary quality, diversity and equilibrium, was calculated. Associations between the DQI-A and food and nutrient intakes and blood concentration biomarkers were investigated using multilevel regression analysis corrected for centre, age and sex. DQI-A scores were associated with food intake in the expected direction: positive associations with nutrient-dense food items, such as fruits and vegetables, and inverse associations with energy-dense and low-nutritious foods. On the nutrient level, the DQI-A was positively related to the intake of water, fibre and most minerals and vitamins. No association was found between the DQI-A and total fat intake. Furthermore, a positive association was observed with 25-hydroxyvitamin D, holo-transcobalamin and n-3 fatty acid serum levels. The present study has shown good validity of the DQI-A by confirming the expected associations with food and nutrient intakes and some biomarkers in blood.

Main characteristics and participation rate of European adolescents included in the HELENA study

Background

Participation rate and response rate are key issues in a cross sectional large-scale epidemiological study. The objective of this paper is to describe the study population and to evaluate participation and response rate as well as the key nutritional status variables in male and female adolescents involved in the HELENA study.

Methods

A multi-stage random cluster sampling with a target sample of 3000 adolescents aged [12.5 to 17.5] years, stratified for geographical location and age, was carried out. Information for participants and non-participants (NP) was compared, and participation and response rates to specific questionnaires were discussed.

Results

3,865 adolescents aged [12.5 to 17.5] years (1,845 females) participated in the HELENA study, of whom 1,076 (568 females) participated in the blood sampling. 3,528 (1,845 females) adolescents were finally kept for statistical analysis. Participation rates for the schools and classes differed importantly between countries. The participation rate of pupils within the participating classes also differed importantly between countries. Sex ratio, mean age and BMI were similar between NP and participating adolescents within each centre, and in the overall sample. For all the questionnaires included in the database, the response rate of questionnaires was high (more than 80% of questions were completed).

Conclusion

From this study it could be concluded that participation rate differed importantly between countries, though no bias could be identified when comparing the key study variables between participants and non-participants. Response rate for questionnaires was very high. Future studies investigating lifestyle and health in adolescents can optimize their methods when considering the opportunities and barriers observed in the HELENA study.

Dietary fatty acid intake, its food sources and determinants in European adolescents: the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study

Dietary fatty acids (FA) play a role in several (patho)physiological processes at any age, and different FA have different effects on lipid status and health outcome. The present study aims to describe the FA intake and its main food sources in a population of healthy European adolescents and to assess the variation in intake as a function of non-dietary factors. FA intake was assessed with 24 h recall interviews in 1804 adolescents aged 12·5-17·5 years. Usual intakes were calculated using the multiple source method. Multilevel analyses, adjusting for study centre, were used to investigate the influence of non-dietary factors. The mean total fat intake was 33·3 (sd 1·2) % of total energy intake (%E). The mean SFA intake was 13·8 (sd 1·2) %E, with 99·8 % of the population exceeding the recommendations. SFA was mainly delivered by meat and cake, pies and biscuits. In most adolescents, the PUFA intake was too low, and 35·5 % of the population did not achieve the minimum recommended intake for α-linolenic acid (ALA). The main determinants of FA intake in the present study population were age and sex, as well as physical activity in the male subgroup. No contributions of body composition, socio-economic status or sexual maturation to the variance in FA intake were observed. In conclusion, the most important public health concerns regarding FA intake in this adolescent population were the low intake of ALA and the high intake of SFA, mainly seen in the younger-aged boys. In this group the major contributor to SFA was meat.

The effect of ponderal index at birth on the relationships between common LEP and LEPR polymorphisms and adiposity in adolescents

This study examined the effect of ponderal index (PI) at birth on the relationships between eight common polymorphisms of the leptin (LEP) and leptin receptor (LEPR) genes and adiposity in adolescents. A total of 823 European adolescents (45.4% girls) aged 14.8 ± 1.4 years were genotyped for the LEP (rs2167270, rs12706832, rs10244329, rs2071045, and rs3828942) and LEPR (rs1137100, rs1137101, and rs8179183) polymorphisms. The PI was calculated from parental reports of birth weight and length. Fat mass index (FMI) was calculated. Analyses were adjusted for relevant confounders. An "adiposity-risk-allele score" based on genotypes at the three single-nucleotide polymorphisms (SNPs) associated with adolescents' FMI in adolescents within the lower tertile of PI was calculated. The LEP rs10244329 and rs3828942 polymorphisms were associated with higher FMI only in adolescents within the lower PI tertile (+0.55 kg/m(2) per minor T allele, P = 0.040, and +0.58 kg/m(2) per major G allele, P = 0.028, respectively). The LEPR rs8179183 polymorphism was significantly associated with higher FMI in adolescents within the lower PI tertile (+0.87 kg/m(2) per minor C allele, P = 0.006). After correction for multiple comparisons, only the association between the LEPR rs8179183 and FMI persisted. However, each additional risk allele conferred 0.53 kg/m(2) greater FMI in adolescents within the lower tertile of PI (P = 0.008). In conclusion, our results suggest that those adolescents born with lower PI could be more vulnerable to the influence of the LEP rs10244329 and rs3828942 polymorphisms and LEPR rs8179183 polymorphism on total adiposity content. Due to the relatively small sample size, these findings should be replicated in further larger population samples.

Beverage consumption among European adolescents in the HELENA study

BACKGROUND/OBJECTIVES

Our objective was to describe the fluid and energy consumption of beverages in a large sample of European adolescents.

SUBJECTS/METHODS

We used data from 2741 European adolescents residing in 8 countries participating in the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS). We averaged two 24-h recalls, collected using the HELENA-dietary assessment tool. By gender and age subgroup (12.5-14.9 years and 15-17.5 years), we examined per capita and per consumer fluid (milliliters (ml)) and energy (kilojoules (kJ)) intake from beverages and percentage consuming 10 different beverage groups.

RESULTS

Mean beverage consumption was 1611 ml/day in boys and 1316 ml/day in girls. Energy intake from beverages was about 1966 kJ/day and 1289 kJ/day in European boys and girls, respectively, with sugar-sweetened beverages (SSBs) (carbonated and non-carbonated beverages, including soft drinks, fruit drinks and powders/concentrates) contributing to daily energy intake more than other groups of beverages. Boys and older adolescents consumed the most amount of per capita total energy from beverages. Among all age and gender subgroups, SSBs, sweetened milk (including chocolate milk and flavored yogurt drinks all with added sugar), low-fat milk and fruit juice provided the highest amount of per capita energy. Water was consumed by the largest percentage of adolescents followed by SSBs, fruit juice and sweetened milk. Among consumers, water provided the greatest fluid intake and sweetened milk accounted for the largest amount of energy intake followed by SSBs. Patterns of energy intake from each beverage varied between countries.

CONCLUSIONS

European adolescents consume an average of 1455 ml/day of beverages, with the largest proportion of consumers and the largest fluid amount coming from water. Beverages provide 1609 kJ/day, of which 30.4%, 20.7% and 18.1% comes from SSBs, sweetened milk and fruit juice, respectively.

Food intake of European adolescents in the light of different food-based dietary guidelines: results of the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study

Objective

Since inadequate food consumption patterns during adolescence are not only linked with the occurrence of obesity in youth but also with the subsequent risk of developing diseases in adulthood, the establishment and maintenance of a healthy diet early in life is of great public health importance. Therefore, the aim of the present study was to describe and evaluate the food consumption of a well-characterized sample of European adolescents against food-based dietary guidelines for the first time.

Design

The HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study is a cross-sectional study, whose main objective was to obtain comparable data on a variety of nutritional and health-related parameters in adolescents aged 12·5–17·5 years.

Setting

Ten cities in Europe.

Subjects

The initial sample consisted of more than 3000 European adolescents. Among these, 1593 adolescents (54 % female) had sufficient and plausible dietary data on energy and food intakes from two 24 h recalls using the HELENA-DIAT software.

Results

Food intake of adolescents in Europe is not optimal compared with the two food-based dietary guidelines, Optimized Mixed Diet and Food Guide Pyramid, examined in this study. Adolescents eat half of the recommended amount of fruit and vegetables and less than two-thirds of the recommended amount of milk (and milk products), but consume much more meat (and meat products), fats and sweets than recommended. However, median total energy intake may be estimated to be nearly in line with the recommendations.

Conclusion

The results urge the need to improve the dietary habits of adolescents in order to maintain health in later life.

Vitamin D status among adolescents in Europe: the Healthy Lifestyle in Europe by Nutrition in Adolescence study

An adequate vitamin D status is essential during childhood and adolescence, for its important role in cell growth, skeletal structure and development. It also reduces the risk of conditions such as CVD, osteoporosis, diabetes mellitus, infections and autoimmune disease. As comparable data on the European level are lacking, assessment of vitamin D concentrations was included in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study. Fasting blood samples were obtained from a subsample of 1006 adolescents (470 males; 46·8 %) with an age range of 12·5-17·5 years, selected in the ten HELENA cities in the nine European countries participating in this cross-sectional study, and analysed for 25-hydroxycholecalciferol (25(OH)D) by ELISA using EDTA plasma. As specific reference values for adolescents are missing, percentile distribution were computed by age and sex. Median 25(OH)D levels for the whole population were 57·1 nmol/l (5th percentile 24·3 nmol/l, 95th percentile 99·05 nmol/l). Vitamin D status was classified into four groups according to international guidelines (sufficiency/optimal levels ≥ 75 nmol/l; insufficiency 50-75 nmol/l; deficiency 27·5-49·99 nmol/l and severe deficiency < 27·5 nmol/l). About 80 % of the sample had suboptimal levels (39 % had insufficient, 27 % deficient and 15 % severely deficient levels). Vitamin D concentrations increased with age (P < 0·01) and tended to decrease according to BMI. Geographical differences were also identified. Our study results indicate that vitamin D deficiency is a highly prevalent condition in European adolescents and should be a matter of concern for public health authorities.

Nutritional knowledge in European adolescents: results from the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study

OBJECTIVE

To build up sufficient knowledge of a 'healthy diet'. Here, we report on the assessment of nutritional knowledge using a uniform method in a large sample of adolescents across Europe.

DESIGN

A cross-sectional study.

SETTING

The European multicentre HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study conducted in 2006-2007 in ten cities in Austria, Belgium, France, Germany, Greece (one inland and one island city), Hungary, Italy, Spain and Sweden.

SUBJECTS

A total of 3546 adolescents (aged 12·5-17·5 years) completed a validated nutritional knowledge test (NKT). Socio-economic variables and anthropometric data were considered as potential confounders.

RESULTS

NKT scores increased with age and girls had higher scores compared with boys (62% v. 59%; P < 0·0001). Scores were approximately 10% lower in 'immigrant' adolescents or in adolescents with 'immigrant' mothers. Misconceptions with respect to the sugar content in food or in beverages were found. Overall, there was no correlation between BMI values and NKT scores. After categorization according to BMI, scores increased significantly with BMI group only in boys. These differences disappeared after controlling for socio-economic status (SES). Smoking status and educational level of the mother influenced the NKT scores significantly in boys, as well as the educational levels of both parents in girls.

CONCLUSIONS

Nutritional knowledge was modest in our sample. Interventions should be focused on the lower SES segments of the population. They should be initiated at a younger age and should be combined with environmental prevention (e.g. healthy meals in school canteens).

Short sleep duration is associated with increased obesity markers in European adolescents: effect of physical activity and dietary habits. The HELENA study

BACKGROUND

Adequate sleep is a critical factor for adolescent's health and health-related behaviors.

OBJECTIVE

(a) to describe sleep duration in European adolescents from nine countries, (b) to assess the association of short sleep duration with excess adiposity and (c) to elucidate if physical activity (PA), sedentary behaviors and/or inadequate food habits underlie this association.

DESIGN

A sample of 3311 adolescents (1748 girls) aged 12.5-17.49 years from 10 European cities in Austria, Belgium, France, Germany, Greece, Hungary, Italy, Spain and Sweden was assessed in the Healthy Lifestyle in Europe by Nutrition in Adolescence Study between 2006 and 2008. We measured anthropometric data, sleep duration, PA (accelerometers and questionnaire), television watching and food habits (Food Frequency Questionnaire).

RESULTS

Average duration of daily sleep was 8 h. Shorter sleepers showed higher values of BMI, body fat, waist and hip circumferences and fat mass index (P<0.05), particularly in females. Adolescents who slept <8 h per day were more sedentary, as assessed by accelerometry, and spent more time watching TV (P<0.05). The proportion of adolescents who eat adequate amounts of fruits, vegetables and fish was lower in shorter sleepers than in adolescents who slept ≥8 h per day, and so was the probability of having adequate food habits (P<0.05). Correlation analysis indicated that short sleep is associated with higher obesity parameters.

CONCLUSIONS

In European adolescents, short sleep duration is associated with higher adiposity markers, particularly in female adolescents. This association seems to be related to both sides of the energy balance equation due to a combination of increased food intake and more sedentary habits.

The International Fitness Scale (IFIS): usefulness of self-reported fitness in youth

BACKGROUND

We examined: (i) the usefulness of the International Fitness Scale (IFIS) to correctly rank adolescents into physical fitness levels; (ii) the capacity of the IFIS for predicting cardiovascular disease (CVD) risk; and (iii) the reliability of the IFIS in adolescents.

METHODS

The study comprised 3059 adolescents (aged 12.5-17.5 years) from nine European countries (HELENA study). Blood samples were collected in one-third of the participants (randomly selected, n = 981). Test-retest reliability of the IFIS was studied in a separate sample of 277 adolescents. Physical fitness-cardiorespiratory fitness (CRF), muscular fitness (MF), speed-agility (SP-AG), flexibility and overall fitness-was self-reported using 5-point Likert-scale questions (1 = very poor, 5 = very good) and measured using standard field-based tests. The CVD risk factors measured included total/central adiposity indices and mean arterial pressure, total and high density lipoprotein cholesterol, triglycerides, insulin resistance (HOMA) and C-reactive protein.

RESULTS

Analysis of covariance showed that adolescents reporting better fitness had higher measured fitness levels for all the variables studied (all P < 0.001), regardless of gender, age and weight status. Adolescents reporting very good overall fitness, CRF and SP-AG had a healthier cardiovascular profile in eight out of nine CVD risk factors studied. Perfect agreement (same test-retest answer) was observed in 65% of the adolescents and perfect-acceptable agreement (same answer or ±1) in 97% of the adolescents.

CONCLUSIONS

(i) The IFIS is able to correctly rank adolescents according to their measured physical fitness levels; (ii) adolescents reporting a good/very good overall fitness, CRF or SP-AG have a more favorable cardiovascular profile; and (iii) The IFIS is reliable in adolescents.

Pilot evaluation of the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Food-O-Meter, a computer-tailored nutrition advice for adolescents: a study in six European cities

OBJECTIVE

To investigate the feasibility and impact of the Food-O-Meter, an Internet-based computer-tailored nutrition intervention in adolescents.

DESIGN

Participants in the intervention condition received the computer-tailored advice at baseline and at 1 month, those in the control condition received standardised advice. Effects were evaluated at 1 month (n 621) and at 3 months (n 558) using multi-level modelling.

SETTING

Secondary schools in six European cities. Adolescents accessed the intervention in the school computer room under the supervision of teachers.

SUBJECTS

Classes with students aged 12-17 years in the schools participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) cross-sectional study were randomised into intervention and control schools.

RESULTS

In most participating centres the intervention was feasible and generally well appreciated, especially by girls. Technical problems and lack of motivation of the teachers hindered implementation in some centres. Overweight adolescents had higher scores for reading and using the advice than normal weight adolescents. After 1 month adolescents receiving the standardised advice reported an increase in fat intake, while fat intake in the intervention condition was stable (F = 4·82, P < 0·05). After 3 months, there was a trend in the total group for an intervention effect of the tailored advice on fat intake (F = 2·80, P < 0·10). In the overweight group there was a clear positive effect (F = 5·76, P < 0·05).

CONCLUSIONS

The Food-O-Meter should be developed further. The results were modest but clear for percentage energy from fat, specifically in the overweight group. Adaptations based on new research are needed to enhance the reliability and effectiveness of the intervention.

Availability of data assessing the prevalence and trends of overweight and obesity among European adolescents

OBJECTIVE

To review recent data on objectively measured overweight/obesity in national representative samples of European adolescents (aged 10-18 years), as well as availability of studies assessing trends in overweight/obesity in this target group. Attention was paid to the ability of the data to describe the obesity epidemic, especially in sociodemographic subgroups.

DESIGN/SETTING/SUBJECTS

Data on prevalence and trends in overweight/obesity among adolescents in the twenty-seven European Community member states, Iceland, Norway and Switzerland, available as scientific publications as well as reports or unpublished data by the end of 2009, were retrieved. Reports on the most recent objectively measured data from national representative samples were selected and described with regard to the years of data collection, sample sizes, response rates, age ranges included, trends by age, type of measures of overweight/obesity, sociodemographic variables and the sources of information.

RESULTS

Objectively measured data on national representative samples were identified for only half of the countries, and the trend studies were mainly conducted applying subnational samples. Most studies used the criteria from the International Obesity Task Force (IOTF) to define overweight/obesity, but the age ranges studied and the years of data collection varied, and information on sample sizes and response rates were often not presented. Data on trends of overweight/obesity over time are increasing, and the most recent studies indicate that the prevalence rate of overweight/obesity has stabilized. Few studies reported data by sociodemographic subgroups other than gender and age.

CONCLUSIONS

Objectively measured data on national representative samples of adolescents appear scattered, and there is a large heterogeneity with respect to the quality and comparability of available data. Increasing use of the IOTF criteria for overweight/obesity contributes to improved comparability across studies. Data by sociodemographic subgroups, and in particular by socio-economic status, are scarce.

Association between the FTO rs9939609 polymorphism and leptin in European adolescents: a possible link with energy balance control. The HELENA study

We examined the association between the FTO rs9939609 polymorphism and serum leptin concentrations in adolescents. The FTO rs9939609 polymorphism was genotyped, and fasting serum leptin and insulin were measured in 655 European adolescents (365 females) aged 14.6 ± 1.2 years. We measured weight, height, triceps and subscapular skinfolds and waist circumference, and body fat percentage was calculated. Sex, pubertal status, center, physical activity (accelerometry), total or central adiposity and serum insulin concentrations were entered as confounders in the analyses. The minor A allele of the FTO rs9939609 was significantly associated with higher serum leptin concentrations independently of potential confounders including adiposity (+3.9 ng ml(-1) per risk allele (95% confidence interval: 2.0, 5.9); adjusted P < 0.001). These findings could link the FTO gene with serum leptin and consequently with the control of energy balance. Leptin could be a possible intermediary contributing to the association between the FTO rs9939609 polymorphism and adiposity.

Evaluation of a computer-tailored physical activity intervention in adolescents in six European countries: the Activ-O-Meter in the HELENA intervention study

PURPOSE

The present study investigates the effect of the Activ-O-Meter, an internet-based computer-tailored physical activity intervention in adolescents in six European centers involved in the HELENA study.

METHODS

Adolescents (12-17 years old) from Vienna, Ghent, Heraklion, Dortmund, Athens, and Stockholm were randomized into intervention and control schools. Participants in the intervention condition received the computer-tailored advice at baseline and after 1 month. Participants in the control condition received a generic standard advice. Effects were evaluated after 1 (n = 675) and 3 months (n = 494) using multi-level modeling. Physical activity levels were measured using the International Physical Activity Questionnaire for adolescents (IPAQ-A).

RESULTS

After 1 month, the intervention group reported higher levels of moderate (beta = -32.8, 95% CI (confidence interval): -64.2 to -1.4) and vigorous (beta = -28.0, 95% CI: -50.7 to -5.3) physical activity in leisure time, as well as higher levels of cycling for transport (beta = -19.1, 95% CI: -34.4 to -7.6) compared to the control group. After 3 months, when the intervention group had received the tailored feedback twice, intervention effects were even stronger. Favorable changes in physical activity levels of all intensities and in different contexts were found in the tailored group compared to the control group. Among adolescents not reaching the physical activity recommendations at baseline similar effects as in the total sample were found.

CONCLUSIONS

The data indicated that the computer-tailored physical activity intervention had positive effects on physical activity levels among the adolescents. However, the implementation of the computer-tailored intervention in the schools was not feasible in all countries.

Self-reported physical activity in European adolescents: results from the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study

OBJECTIVE

To describe self-reported physical activity (PA) patterns in the various domains (school, home, transport, leisure time) and intensity categories (walking, moderate PA, vigorous PA) in European adolescents. Furthermore, self-reported PA patterns were evaluated in relation to gender, age category, weight status category and socio-economic status (SES).

DESIGN

Cross-sectional study.

SETTING

Ten European cities.

SUBJECTS

In total, 3051 adolescents (47·6 % boys, mean age 14·8 (sd 1·2) years) completed an adolescent-adapted version of the validated International Physical Activity Questionnaire.

RESULTS

The total sample reported most PA during leisure time (485 min/week) and least PA at home (140 min/week). Boys reported significantly more school-based PA (P < 0·001), leisure-time PA (P = 0·003), vigorous PA (P < 0·001) and total PA (P = 0·002) than girls, while girls reported more home-based PA (P < 0·001) and walking (P = 0·002) than boys. Self-reported PA at school (P < 0·001), moderate PA (P < 0·001), vigorous PA (P < 0·001) and total PA (P < 0·001) were significantly higher in younger age groups than in older groups. Groups based on weight status differed significantly only in leisure-time PA (P = 0·004) and total PA (P = 0·003), while groups based on SES differed in all PA domains and intensities except transport-related PA and total PA.

CONCLUSIONS

The total sample of adolescents reported different scores for the different PA domains and intensity categories. Furthermore, patterns were different according the adolescents' gender, age, weight status and SES.

Biomarker evaluation of Greek adolescents' exposure to secondhand smoke

Exposure to secondhand smoke (SHS) is a significant threat to public health, and represents a danger for both the development and health status of children and adolescents. Taking the above into account, our aim was to quantify Greek adolescents' exposure to SHS using serum cotinine levels. During 2006, 341 adolescents aged 13-17 were randomly selected from high schools in Heraklion and agreed to participate as part of the European Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study. Blood samples were drawn from a random sample of 106 adolescents, while serum cotinine/nicotine concentrations were measured by Gas Chromatography-Mass Spectrometry (GC-MS). The mean levels of serum cotinine and nicotine were calculated at 1.60 +/- 2.18 ng/mL and 4.48 +/- 4.00 ng/mL, respectively, while 97.7% of the non-smoker adolescents were found to have measureable levels of serum cotinine indicating exposure to SHS. The analysis revealed that their paternal (p = .001) and maternal smoking habits (p = .018) as also the existence of a younger brother or sister (p = .008) were the main modifiers of SHS exposure during adolescence. Conclusively, almost all of the measured Greek adolescents were exposed to SHS, even when their parents were non-smokers. This finding indicates the need for both community and school-based educational programmes as also the implementation of a comprehensive ban on smoking in public places.

Chronic stress and obesity in adolescents: scientific evidence and methodological issues for epidemiological research

AIMS

This review describes the role of chronic stress in the development of obesity and available methodologies for the assessment of chronic stress in humans, in particular adolescents, with the aim of developing a feasible methodology to implement in an epidemiological study.

DATA SYNTHESIS

Chronic stress seems to be associated with the aetiology of obesity by interacting with both mechanisms of energy intake (increase of appetite and energy intake) and expenditure (decrease of physical activity) and by stimulating visceral fat accumulation in favour of abdominal obesity. However, more research is necessary to unravel the underlying mechanisms of the obesity-inducing effects of chronic stress, especially in adolescents. In addition to experimental research, epidemiological observational studies, in particular cohort studies, are appropriate given their non-intervening character, lower budgetary costs and natural setting. In practice, stress can be assessed by means of either a subjective approach using stressor checklists or interviews, or an objective approach measuring biomarkers of stress. In epidemiological research in adolescents, a combination of both strategies is recommended, with a preference for a general stressor checklist for adolescents and measurement of salivary cortisol, one of the most used and well-characterized biomarkers of stress.

CONCLUSION

This review provides basic evidence for the positive association between chronic stress and obesity, but also points out the need for more research in adolescents to further elucidate the role of chronic stress in the aetiology of obesity in this crucial life period. Good, well-standardized epidemiological surveys could be of great benefit in this research area.

Design and implementation of the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study

OBJECTIVE

To provide an overview of the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS) design, with particular attention to its quality control procedures. Other important methodological aspects are described in detail throughout this supplement.

DESIGN

Description of the HELENA-CSS sampling and recruitment approaches, standardization and harmonization processes, data collection and analysis strategies and quality control activities.

RESULTS

The HELENA-CSS is a multi-centre collaborative study conducted in European adolescents located in urban settings. The data management systems, quality assurance monitoring activities, standardized manuals of operating procedures and training and study management are addressed in this paper. Various quality controls to ensure collection of valid and reliable data will be discussed in this supplement, as well as quantitative estimates of measurement error.

CONCLUSION

The great advantage of the HELENA-CSS is the strict standardization of the fieldwork and the blood analyses, which precludes to a great extent the kind of immeasurable confounding bias that often interferes when comparing results from isolated studies.