Dietary assessment methods in surveillance systems targeted to adolescents: A review of the literature

AIMS

The present paper aims to identify ongoing multinational surveillance systems (SURSYSs) assessing diet and nutrition targeted to adolescents, including European surveys involving multiple countries and similar initiatives conducted in non-European countries with developed economies, and to describe the dietary assessment methods used.

DATA SYNTHESIS

A total of 13 SURSYSs conducted in Europe, USA, Canada, Australia and New Zealand were identified. Dietary assessment methods commonly used include 24-h recalls (24H-Rs) and questionnaires or interviews. Food frequency questionnaires (FFQs) are used in combination with 24H-Rs in six SURSYSs: only FFQs are used in four SURSYSs; 24H-Rs only in one system and a 24H-R in combination with a general questionnaire/interview in one SURSYS. Eleven systems collect information also on some dietary habits and ten systems on other nutritional indicators such as anthropometric and/or biochemical measures. The FFQs used are not homogeneous and often include limited food or beverage items such as fruits and vegetables or sugar-sweetened beverages. In seven systems, foods specifically consumed by adolescents, such as fast food or snacks, are not assessed; instead, a total of seven systems collect data on supplement intake and just in very few cases on fats, legumes and/or water.

CONCLUSIONS

This study detected considerable variability across the systems identified, suggesting the need for a SURSYS targeted to adolescents that gathers as much as possible complete dietary information, with standardised methodology and regular periodicity. The detailed information provided by this review could be useful to national authorities for the choice of protocols to be applied in their own national surveys.

Secondhand smoke exposure at home among one billion children in 21 countries: findings from the Global Adult Tobacco Survey (GATS)

OBJECTIVE

Children are vulnerable to secondhand smoke (SHS) exposure because of limited control over their indoor environment. Homes remain the major place where children may be exposed to SHS. Our study examines the magnitude, patterns and determinants of SHS exposure in the home among children in 21 countries (19 low-income and middle-income countries and 2 high-income countries).

METHODS

Global Adult Tobacco Survey (GATS) data, a household survey of people 15 years of age or older. Data collected during 2009-2013 were analysed to estimate the proportion of children exposed to SHS in the home. GATS estimates and 2012 United Nations population projections for 2015 were also used to estimate the number of children exposed to SHS in the home.

RESULTS

The proportion of children younger than 15 years of age exposed to SHS in the home ranged from 4.5% (Panama) to 79.0% (Indonesia). Of the approximately one billion children younger than 15 years of age living in the 21 countries under study, an estimated 507.74 million were exposed to SHS in the home. China, India, Bangladesh, Indonesia and the Philippines accounted for almost 84.6% of the children exposed to SHS. The prevalence of SHS exposure was higher in countries with higher adult smoking rates and was also higher in rural areas than in urban areas, in most countries.

CONCLUSIONS

A large number of children were exposed to SHS in the home. Encouraging of voluntary smoke-free rules in homes and cessation in adults has the potential to reduce SHS exposure among children and prevent SHS-related diseases and deaths.

Socioeconomic inequalities in childhood overweight: heterogeneity across five countries in the WHO European Childhood Obesity Surveillance Initiative (COSI-2008)

Background:

Excess risk of childhood overweight and obesity occurring in socioeconomically disadvantaged families has been demonstrated in numerous studies from high-income regions, including Europe. It is well known that socioeconomic characteristics such as parental education, income and occupation are etiologically relevant to childhood obesity. However, in the pan-European setting, there is reason to believe that inequalities in childhood weight status may vary among countries as a function of differing degrees of socioeconomic development and equity.

Subjects and Methods:

In this cross-sectional study, we have examined socioeconomic differences in childhood obesity in different parts of the European region using nationally representative data from Bulgaria, the Czech Republic, Lithuania, Portugal and Sweden that were collected in 2008 during the first round of the World Health Organization (WHO) European Childhood Obesity Surveillance Initiative.

Results:

Heterogeneity in the association between parental socioeconomic indicators and childhood overweight or obesity was clearly observed across the five countries studied. Positive as well as negative associations were observed between parental socioeconomic indicators and childhood overweight, with statistically significant interactions between country and parental indicators.

Conclusions:

These findings have public health implications for the WHO European Region and underscore the necessity to continue documenting socioeconomic inequalities in obesity in all countries through international surveillance efforts in countries with diverse geographic, social and economic environments. This is a prerequisite for universal as well as targeted preventive actions.

WHO European Childhood Obesity Surveillance Initiative: associations between sleep duration, screen time and food consumption frequencies

BACKGROUND

Both sleep duration and screen time have been suggested to affect children's diet, although in different directions and presumably through different pathways. The present cross-sectional study aimed to simultaneously investigate the associations between sleep duration, screen time and food consumption frequencies in children.

METHODS

The analysis was based on 10 453 children aged 6-9 years from five European countries that participated in the World Health Organization European Childhood Obesity Surveillance Initiative. Logistic multilevel models were used to assess associations of parent-reported screen time as well as sleep duration (exposure variables) with consumption frequencies of 16 food items (outcome variables). All models were adjusted for age, sex, outdoor play time, maximum educational level of parents and sleep duration or screen time, depending on the exposure under investigation.

RESULTS

One additional hour of screen time was associated with increased consumption frequencies of 'soft drinks containing sugar' (1.28 [1.19;1.39]; odds ratio and 99% confidence interval), 'diet/light soft drinks' (1.21 [1.14;1.29]), 'flavoured milk' (1.18 [1.08;1.28]), 'candy bars or chocolate' (1.31 [1.22;1.40]), 'biscuits, cakes, doughnuts or pies' (1.22 [1.14;1.30]), 'potato chips (crisps), corn chips, popcorn or peanuts' (1.32 [1.20;1.45]), 'pizza, French fries (chips), hamburgers'(1.30 [1.18;1.43]) and with a reduced consumption frequency of 'vegetables (excluding potatoes)' (0.89 [0.83;0.95]) and 'fresh fruits' (0.91 [0.86;0.97]). Conversely, one additional hour of sleep duration was found to be associated with increased consumption frequencies of 'fresh fruits' (1.11 [1.04;1.18]) and 'vegetables (excluding potatoes)' (1.14 [1.07;1.23]).

CONCLUSION

The results suggest a potential relation between high screen time exposure and increased consumption frequencies of foods high in fat, free sugar or salt whereas long sleep duration may favourably be related to children's food choices. Both screen time and sleep duration are modifiable behaviours that may be tackled in childhood obesity prevention efforts.

National physical activity recommendations: systematic overview and analysis of the situation in European countries

Background

Developing national physical activity (PA) recommendations is an essential element of an effective national approach to promote PA.

Methods

Systematic overview and analysis of national PA recommendations across the European Region of the World Health Organization (WHO). The WHO European national information focal points provided information which was complemented through online searches and input from other experts.

Results

Information received until summer 2012 from 37 countries was analyzed. Sixteen countries did not have national recommendations while 21 countries did. For 17 countries, the source document was accessible. Seventeen recommendations referred to adults, 14 to young people and 6 to older adults. Most national recommendations for children and young people are quite similar: 12 countries recommend at least 60 minutes of moderate- to vigorous-intensity PA each day, in line with the WHO global recommendation. Three countries recommend longer durations and one a lower one. In some countries, slight variations were found regarding the recommended intensity and minimum bouts. Only one country was fully in line with the WHO recommendations. Two countries have issued separate recommendations for pre-school children. For adults, most countries still follow the 1995 United States recommendations of “at least 30 minutes on 5 days a week”. Three countries were fully in line with the WHO recommendations. Four countries give specific recommendations on reducing weight, avoiding weight gain or continuing weight maintenance. The six identified national PA recommendations for older adults are mainly similar to those for adults but underline that particularly for this age group also less activity has important health benefits; four countries also recommend balance training.

Conclusions

About half of the countries for which information was available and likely less than 40% of all 53 countries in the WHO European Region have developed national PA recommendations. Further investment is needed to address this important step towards a comprehensive PA promotion approach. Much remains to be done for the 2010 WHO recommendations to be fully reflected in national documents across all parts of the Region and all age groups. In addition, avoiding extended periods of inactivity and overweight are only addressed by a minority of countries yet.

WHO European Childhood Obesity Surveillance Initiative: School nutrition environment and body mass index in primary schools

BACKGROUND

Schools are important settings for the promotion of a healthy diet and sufficient physical activity and thus overweight prevention.

OBJECTIVE

To assess differences in school nutrition environment and body mass index (BMI) in primary schools between and within 12 European countries.

METHODS

Data from the World Health Organization (WHO) European Childhood Obesity Surveillance Initiative (COSI) were used (1831 and 2045 schools in 2007/2008 and 2009/2010, respectively). School personnel provided information on 18 school environmental characteristics on nutrition and physical activity. A school nutrition environment score was calculated using five nutrition-related characteristics whereby higher scores correspond to higher support for a healthy school nutrition environment. Trained field workers measured children's weight and height; BMI-for-age (BMI/A) Z-scores were computed using the 2007 WHO growth reference and, for each school, the mean of the children's BMI/A Z-scores was calculated.

RESULTS

Large between-country differences were found in the availability of food items on the premises (e.g., fresh fruit could be obtained in 12%-95% of schools) and school nutrition environment scores (range: 0.30-0.93). Low-score countries (Bulgaria, Czech Republic, Greece, Hungary, Latvia and Lithuania) graded less than three characteristics as supportive. High-score (≥0.70) countries were Ireland, Malta, Norway, Portugal, Slovenia and Sweden. The combined absence of cold drinks containing sugar, sweet snacks and salted snacks were more observed in high-score countries than in low-score countries. Largest within-country school nutrition environment scores were found in Bulgaria, Czech Republic, Greece, Hungary, Latvia and Lithuania. All country-level BMI/A Z-scores were positive (range: 0.20-1.02), indicating higher BMI values than the 2007 WHO growth reference. With the exception of Norway and Sweden, a country-specific association between the school nutrition environment score and the school BMI/A Z-score was not observed.

CONCLUSIONS

Some European countries have implemented more school policies that are supportive to a healthy nutrition environment than others. However, most countries with low school nutrition environment scores also host schools with supportive school environment policies, suggesting that a uniform school policy to tackle the "unhealthy" school nutrition environment has not been implemented at the same level throughout a country and may underline the need for harmonized school policies.

WHO European Childhood Obesity Surveillance Initiative: body mass index and level of overweight among 6-9-year-old children from school year 2007/2008 to school year 2009/2010

Background

The World Health Organization (WHO) Regional Office for Europe has established the Childhood Obesity Surveillance Initiative (COSI) to monitor changes in overweight in primary-school children. The aims of this paper are to present the anthropometric results of COSI Round 2 (2009/2010) and to explore changes in body mass index (BMI) and overweight among children within and across nine countries from school years 2007/2008 to 2009/2010.

Methods

Using cross-sectional nationally representative samples of 6−9-year-olds, BMI, anthropometric Z-scores and overweight prevalence were derived from measured weight and height. Significant changes between rounds were assessed using variance and t-tests analyses.

Results

At Round 2, the prevalence of overweight (including obesity; WHO definitions) ranged from 18% to 57% among boys and from 18% to 50% among girls; 6 − 31% of boys and 5 − 21% of girls were obese. Southern European countries had the highest overweight prevalence. Between rounds, the absolute change in mean BMI (range: from −0.4 to +0.3) and BMI-for-age Z-scores (range: from −0.21 to +0.14) varied statistically significantly across countries. The highest significant decrease in BMI-for-age Z-scores was found in countries with higher absolute BMI values and the highest significant increase in countries with lower BMI values. The highest significant decrease in overweight prevalence was observed in Italy, Portugal and Slovenia and the highest significant increase in Latvia and Norway.

Conclusions

Changes in BMI and prevalence of overweight over a two-year period varied significantly among European countries. It may be that countries with higher prevalence of overweight in COSI Round 1 have implemented interventions to try to remedy this situation.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2458-14-806) contains supplementary material, which is available to authorized users.

WHO European Childhood Obesity Surveillance Initiative 2008: weight, height and body mass index in 6-9-year-old children

What is already known about this subject Overweight and obesity prevalence estimates among children based on International Obesity Task Force definitions are substantially lower than estimates based on World Health Organization definitions. Presence of a north-south gradient with the highest level of overweight found in southern European countries. Intercountry comparisons of overweight and obesity in primary-school children in Europe based on measured data lack a similar data collection protocol. What this study adds Unique dataset on overweight and obesity based on measured weights and heights in 6-9-year-old children from 12 European countries using a harmonized surveillance methodology. Because of the use of a consistent data collection protocol, it is possible to perform valid multiple comparisons between countries. It demonstrates wide variations in overweight and obesity prevalence estimates among primary-school children between European countries and regions.

BACKGROUND

Nutritional surveillance in school-age children, using measured weight and height, is not common in the European Region of the World Health Organization (WHO). The WHO Regional Office for Europe has therefore initiated the WHO European Childhood Obesity Surveillance Initiative.

OBJECTIVE

To present the anthropometric results of data collected in 2007/2008 and to investigate whether there exist differences across countries and between the sexes.

METHODS

Weight and height were measured in 6-9-year-old children in 12 countries. Prevalence of overweight, obesity, stunting, thinness and underweight as well as mean Z-scores of anthropometric indices of height, weight and body mass index were calculated.

RESULTS

A total of 168 832 children were included in the analyses and a school participation rate of more than 95% was obtained in 8 out of 12 countries. Stunting, underweight and thinness were rarely prevalent. However, 19.3-49.0% of boys and 18.4-42.5% of girls were overweight (including obesity and based on the 2007 WHO growth reference).The prevalence of obesity ranged from 6.0 to 26.6% among boys and from 4.6 to 17.3% among girls. Multi-country comparisons suggest the presence of a north-south gradient with the highest level of overweight found in southern European countries.

CONCLUSIONS

Overweight among 6-9-year-old children is a serious public health concern and its variation across the European Region highly depends on the country. Comparable monitoring of child growth is possible across Europe and should be emphasized in national policies and implemented as part of action plans.

Nutritional and pubertal status influences accuracy of self-reported weight and height in adolescents: the HELENA Study

BACKGROUND AND AIMS

The aim of this study was to assess factors that have an effect on the accuracy of self-reported weight and height in adolescents.

METHODS

Weight and height of 3,865 European adolescents aged 12.5 to 17.5 years were self-reported via specific questionnaire. Then real weight and height were measured using accurate equipment and standardized protocols. Differences (D) between self-reported and measured weight and height were calculated, and factors that could have influenced the accuracy of self-reported weight and height were assessed. Data were analyzed using ANOVA, Student's t test and multivariate regression.

RESULTS

Adolescents underestimated their weight (D = -0.81 kg; n = 2,968) and overestimated their height (D = +0.74 cm; n = 3,308). Obese girls underestimated their weight (D = -4.70 kg) and overestimated their height (D = +0.22 cm) to a greater extent (p < 0.05) than obese boys (D = -3.13 kg and +0.14 cm for weight and height, respectively). Underestimation of weight (D = -1.25 kg) and overestimation of height (D = +0.15 cm) were only significant for girls who had finished puberty (Tanner stage 5). Socioeconomic status, nutritional knowledge, physical fitness, physical activity level, food choice and preference, and healthy eating behaviour had no significant influence on the accuracy of self-reported weight and height.

CONCLUSION

Our data confirms that self-reports of weight and height made by adolescents are inaccurate and demonstrate that inaccuracy is strongly influenced by nutritional status, pubertal status and gender.

Prevalence of obesity among Portuguese children (6-8 years old) using three definition criteria: COSI Portugal, 2008

INTRODUCTION

Previous studies place Portugal among the five countries with the highest prevalence of childhood obesity in Europe. This paper describes the prevalence of thinness, overweight and obesity in Portuguese children of 6-8 years of age, based on the first data collection from Childhood Obesity Surveillance Initiative Portugal, which took place during the 2007/2008 school year.

METHODS

This study uses a semi-longitudinal design with repeated cross-sectional national representative samples. Specific prevalence of overweight (including obesity) and obesity was determined using three different diagnostic criteria. Across the seven geographic regions, 3765 children were enrolled from 181 schools; 50.3% of participants were males.

RESULTS

Using the International Obesity Task Force reference, the prevalence of thinness, overweight and obesity were 4.8%, 28.1% and 8.9%, respectively; using the Center for Disease Control and Prevention reference they were 2.1%, 32.2% and 14.6%, respectively; and according to the World Health Organization reference, they were 1.0%, 37.9% and 15.3%, respectively. Univariate analysis showed a higher risk of obesity in older children, in boys and in the Azores region. The islands of Madeira and the Azores were the regions with the highest prevalence of overweight at 39.4% and 46.6%, respectively, and Algarve was the one with the lowest (21.4%).

CONCLUSION

These findings demonstrate the need for urgent action in Portugal and provide policy-makers with comprehensive and detailed information to assist with this.

Age standardization in mapping adult overweight and obesity trends in the WHO European Region

This study aims to improve comparability of available data within the World Health Organization (WHO) European Region taking into account differences related to the aging of the population. Surveys were included if they were conducted on adults aged 25-64 years between 1985 and 2010 in the WHO European Region. Overweight/obesity prevalences were adjusted to the European standard population aged 25-64. Data were entered for each of the 5-year categories between 1981 and 2010. Measured height and weight data were available for males in 16 and females in 24 of the 53 countries. The 50-64-year-olds had higher prevalence of overweight and obesity as compared to the 25-49-year-olds. This pattern occurs in every country, by male and female, in almost all surveys. Age-standardized overweight prevalence was higher among males than females in all countries. Trend data showed increases in most countries. Age-standardized maps were based on self-reported data because of insufficient availability of measured data. Results showed more countries with available data as well as the higher category of obesity in the later surveys. Measured values are needed and age adjustment is important in documenting emerging overweight and obesity trends, independent of demographic changes, in the WHO European Region.

Worldwide practices in child growth monitoring

OBJECTIVE

To describe child growth monitoring practices worldwide in preparation for the construction and application of a new international growth reference.

STUDY DESIGN

A questionnaire was sent to Ministries of Health in 202 countries requesting information on growth charts used in national programs, reference populations, classification systems, problems encountered, and actions taken against growth faltering. Countries also provided hard copies of charts in current use. This information was entered and analyzed in Microsoft Access.

RESULTS

Responses were received from 178 (88%) countries, 154 of which included growth charts (n=806). Two thirds of the charts covered preschool age. All countries used weight-for-age, over half relying on this index alone. The reference most commonly used (68%) was the National Center for Health Statistics/World Health Organization population, with regional variations, where most European countries used local standards. Sixty-three percent of charts classified child growth on percentiles, whereas about one fifth used z scores. Problems reported were both conceptual (eg, interpreting growth trajectories) and practical (eg, lack of equipment).

CONCLUSIONS

The survey demonstrates that growth charts are used universally in pediatric care. The information gathered on current use and interpretation of growth charts provides important guidance for constructing and applying the new reference.