Assessing, understanding and modifying nutritional status, eating habits and physical activity in European adolescents: The HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study

Objectives

To identify the main knowledge gaps and to propose research lines that will be developed within the European Union-funded ‘Healthy Lifestyle in Europe by Nutrition in Adolescence’ (HELENA) project, concerning the nutritional status, physical fitness and physical activity of adolescents in Europe.

Design

Review of the currently existing literature.

Results

The main gaps identified were: lack of harmonised and comparable data on food intake; lack of understanding regarding the role of eating attitudes, food choices and food preferences; lack of harmonised and comparable data on levels and patterns of physical activity and physical fitness; lack of comparable data about obesity prevalence and body composition; lack of comparable data about micronutrient and immunological status; and lack of effective intervention methodologies for healthier lifestyles.

Conclusions

The HELENA Study Group should develop, test and describe harmonised and state-of-the-art methods to assess the nutritional status and lifestyle of adolescents across Europe; develop and evaluate an intervention on eating habits and physical activity; and develop and test new healthy food products attractive for European adolescents.

Dietary exposure to chemicals within the process of risk assessment: possible applications to substances that may cause allergic reactions

Exposure assessment is one of the key parts of the risk assessment process. This task is crucial when evaluating substances for which only intake of toxicologically-important amounts can lead to adverse health effects. Ideally, dietary exposure to hazardous substances can be assessed by combining data on concentration in all food products with data on their consumption. However, it is considered to be neither cost-effective nor necessary to collect detailed data for every substance, and a stepwise procedure is commonly used to focus resources on the most important issues. Screening methods, designed to look for 'worst case' situations, are first used to target chemicals that might be of health concern for the general population or for certain at-risk groups. The quality of the dietary exposure assessments not only depends on the quality of the data collected, but also on the integration tools used for initial screening or for the eventual more precise estimations. A particular challenge is the evaluation of food allergens and components causing other forms of intolerances, since no reliable data seem to be currently available on the type of exposure (amounts and duration) required to induce a food allergy. A different approach from that used for dietary exposure to other hazardous substances has to be adopted. However, the methodologies (such as those used to collect food consumption data) and databases (in particular, information about food labels) developed in such a context could be useful to investigate the exposure conditions leading to the development of food allergies.

Assessment of dietary intake of flavouring substances within the procedure for their safety evaluation: advantages and limitations of estimates obtained by means of a per capita method

The procedure for the safety evaluation of flavourings adopted by the European Commission in order to establish a positive list of these substances is a stepwise approach which was developed by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and amended by the Scientific Committee on Food. Within this procedure, a per capita amount based on industrial poundage data of flavourings, is calculated to estimate the dietary intake by means of the maximised survey-derived daily intake (MSDI) method. This paper reviews the MSDI method in order to check if it can provide conservative intake estimates as needed at the first steps of a stepwise procedure. Scientific papers and opinions dealing with the MSDI method were reviewed. Concentration levels reported by the industry were compared with estimates obtained with the MSDI method. It appeared that, in some cases, these estimates could be orders of magnitude (up to 5) lower than those calculated considering concentration levels provided by the industry and regular consumption of flavoured foods and beverages. A critical review of two studies which had been used to support the statement that MSDI is a conservative method for assessing exposure to flavourings among high consumers was performed. Special attention was given to the factors that affect exposure at high percentiles, such as brand loyalty and portion sizes. It is concluded that these studies may not be suitable to validate the MSDI method used to assess intakes of flavours by European consumers due to shortcomings in the assumptions made and in the data used. Exposure assessment is an essential component of risk assessment. The present paper suggests that the MSDI method is not sufficiently conservative. There is therefore a clear need for either using an alternative method to estimate exposure to flavourings in the procedure or for limiting intakes to the levels at which the safety was assessed.

Dietary estimated intake of intense sweeteners by Italian teenagers. Present levels and projections derived from the INRAN-RM-2001 food survey

In a previous study, Italian female teenagers regular consumers of sugar free soft drinks and table-top sweeteners were suggested to have a higher intake of intense sweeteners than other teenagers. A food frequency questionnaire designed to identify adolescents who were high consumers of these food products was filled in by a randomly extracted sample of teenagers (n=3982) living in the District of Rome (Italy) in year 2000. A consumer survey was then carried out in a randomly extracted sub-sample of males and females and in all females who reported high consumption of sugar-free soft drinks and/or table-top sweeteners. A total of 362 subjects participated in a detailed food survey by recording, at brand level, all foods and beverages ingested over 12 days. For each sugar-free product, producers provided the concentration of intense sweeteners (saccharin, aspartame, acesulfame K and cyclamate). No intake in excess of the Acceptable Daily Intake (ADI) was observed. Also medicines and supplements were taken into account and these did not result in a large impact on chronic exposure to intense sweeteners. The intake levels did not exceed the ADI even under a worst case scenario which was performed to take into consideration a hypothetical future substitution of all regular food products with their sugar-free version. It can be concluded that, with the observed current consumption patterns and occurrence levels, the risk of an excessive intake of intense sweeteners by Italian teenagers is extremely low.

Development of databases for use in validation studies of probabilistic models of dietary exposure to food chemicals and nutrients

The data currently available in the European Union in terms of food consumption and of food chemical and nutrient concentration data present many limitations when used for estimating intake. The most refined techniques currently available were used within the European Union FP5 Monte Carlo project to estimate, as accurately as possible, the intake of food additives, pesticide residues and nutrients. Databases of 'true' intakes of food additives (based on brand level food consumption records and additive concentration data), pesticide residues (based on duplicate diet studies) and nutrients (based on biomarker studies) have thus been generated. These kind of estimates are rarely repeatable because the databases generated and used to calculate them require an extraordinary expenditure of time and resources. The databases created served the purpose of estimating as accurately as possible 'true' chemical intakes for assessing the validity of additive, nutrient and pesticide probabilistic models.

Probabilistic modelling of human exposure to intense sweeteners in Italian teenagers: validation and sensitivity analysis of a probabilistic model including indicators of market share and brand loyalty

For the assessment of exposure to food-borne chemicals, the most commonly used methods in the European Union follow a deterministic approach based on conservative assumptions. Over the past few years, to get a more realistic view of exposure to food chemicals, risk managers are getting more interested in the probabilistic approach. Within the EU-funded 'Monte Carlo' project, a stochastic model of exposure to chemical substances from the diet and a computer software program were developed. The aim of this paper was to validate the model with respect to the intake of saccharin from table-top sweeteners and cyclamate from soft drinks by Italian teenagers with the use of the software and to evaluate the impact of the inclusion/exclusion of indicators on market share and brand loyalty through a sensitivity analysis. Data on food consumption and the concentration of sweeteners were collected. A food frequency questionnaire aimed at identifying females who were high consumers of sugar-free soft drinks and/or of table top sweeteners was filled in by 3982 teenagers living in the District of Rome. Moreover, 362 subjects participated in a detailed food survey by recording, at brand level, all foods and beverages ingested over 12 days. Producers were asked to provide the intense sweeteners' concentration of sugar-free products. Results showed that consumer behaviour with respect to brands has an impact on exposure assessments. Only probabilistic models that took into account indicators of market share and brand loyalty met the validation criteria.

Stochastic modelling of human exposure to food chemicals and nutrients within the "Montecarlo" project: an exploration of the influence of brand loyalty and market share on intake estimates of intense sweeteners from sugar-free soft drinks

To get a more realistic view of exposure to food chemicals, risk managers are getting more interested in stochastic modelling as an alternative to deterministic approaches based on conservative assumptions. It allows to take into account all the available information in the concentration of the chemical present in foods and in food consumption patterns. Within the EC-funded "Montecarlo" project, a comprehensive set of mathematical algorithms was developed to take into account all the necessary components for stochastic modelling of a variety of food chemicals, nutrients and ingredients. An appropriate computer software is being developed. Since the concentration of food chemicals may vary among different brands of the same product, consumer behaviour with respect to brands may have an impact on exposure assessments. Numeric experiments were carried out on different ways of incorporating indicators of market share and brand loyalty in the mathematical algorithms developed within the stochastic model of exposure to intense sweeteners from sugar-free beverages. The 95th percentiles of intake were shown to vary according to the inclusion/exclusion of these indicators. The market share should be included in the model especially if the market is not equitably distributed between brands. If brand loyalty data are not available, the model may be run under theoretical scenarios.

The relationship between frequency of carbohydrates intake and dental caries: a cross-sectional study in Italian teenagers

OBJECTIVE

To propose an approach for investigation of the relationship between the frequency of carbohydrates intake and dental caries in real-life conditions.

DESIGN

The frequency of separate eating events (with the exclusion of lunch and dinner) and their sugars and starch content were assessed on the basis of diaries collected for seven consecutive days. The total number of decayed, missing and filled teeth (DMFT) was assessed through clinical examination. The interrelation between DMFT and frequency of eating events was analysed through Pearson correlation coefficient and stepwise forward linear regression analysis.

SETTING

Italy.

SUBJECTS

One hundred and ninety-three students (males and females, mean age 16 years) of a secondary school.

RESULTS

Individual DMFT varied between 0 (24% of subjects) and 12, with a mean of 3. Once lunch and dinner were excluded, the mean number of separate eating events was 2.9. A statistically significant relationship was found between DMFT and eating frequency thus defined. Correlations were calculated considering only eating events containing a proportion of sugars or starch higher than different cut-off levels. In a stepwise multiple regression model for DMFT, the frequency of 'high sugars and high starch events' accounted for 8% of the DMFT variance. Overall frequency of separate eating events defined according to their content of both sugars and starch accounted for 18% of the DMFT variance. A stronger correlation was found among males only.

CONCLUSIONS

The precise characterisation of eating events in terms of their sugars and starch content allows us to explain a consistent percentage of the variability in DMFT.

Correlation analyses as a step to identify foods that are sources of inter-individual variability in nutrients; their use for the development of food based dietary guidelines

Food Based Dietary Guidelines (FBDG), in order to be attainable, should take into account the cultural context of the population for which they are developed. They need to focus on foods that actually determine the intake of nutrients for which desirable changes have been identified. Inter-individual variability of nutrient intakes--a measure of the heterogeneity of intakes--is determined by the variability in the consumption of its food sources among the population. The foods that determine a high proportion of inter-individual variability in nutrient intake can be identified on the basis of data banks that describe food and nutrient intakes in the population. The experience accumulated to design Food Frequency Questionnaire through selection of key foods suggests that high quantitative contributors to a specific nutrient may not be important determinants of its intake. On the other hand, the Pearson correlation between the intake of each food source and the total nutrient intake allows quantification of the percentage of variability explained by each item and takes into account the possibility of correlations between different food sources. Once a key food is identified, several strategies are available to modify its intake in the population: through changes in the percentage of consumers/in the mean portion size/in the frequency of intake. The anticipated level of change can be predicted according to the strategy adopted.

Dietary intake exposure to sulphites in Italy--analytical determination of sulphite-containing foods and their combination into standard meals for adults and children

The theoretical risk of exceeding the Acceptable Daily Intake (ADI) for sulphites has mostly been examined on the basis of a worst-case scenario. In order to examine the real situation the determination of residue sulphite levels in ready-to-consume foods is required. The aim of this paper is to assess the actual sulphite content of diets obtained from a combination of realistic meals high in sulphite-containing foods. Food products available in Italy containing added sulphites were identified. Overall, 211 samples of foods and beverages (including 85 samples of wine) were collected. The determination of sulphite residues was carried out on the foods which were prepared according to normal domestic practice. It was shown that the diets obtained from these foods would lead to an intake of 23 mg/day in children and 50 mg/day in adults (both slightly above the ADI for respectively a 30 kg child and a 60 kg adult). Among all sulphite-containing foods, the highest contributors to the intake were dried fruit and wine, both ingested without further treatment. The analysis of specific consumption data confirmed the existence of a risk of exceeding the ADI related to sulphite residue levels in wine.

Estimates of the theoretical maximum daily intake of erythorbic acid, gallates, butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) in Italy: a stepwise approach

The three recent EU directives which fixed maximum permitted levels (MPL) for food additives for all member states also include the general obligation to establish national systems for monitoring the intake of these substances in order to evaluate their use safety. In this work, we considered additives with primary antioxidant technological function for which an acceptable daily intake (ADI) was established by the Scientific Committee for Food (SCF): gallates, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and erythorbic acid. The potential intake of these additives in Italy was estimated by means of a hierarchical approach using, step by step, more refined methods. The likelihood of the current ADI to be exceeded was very low for erythorbic acid, BHA and gallates. On the other hand, the theoretical maximum daily intake (TMDI) of BHT was above the current ADI. The three food categories found to be main potential sources of BHT were "pastry, cake and biscuits", "chewing gums" and "vegetables oils and margarine"; they overall contributed 74% of the TMDI. Actual use of BHT in these food categories is discussed, together with other aspects such as losses of this substance in the technological process and percentage of ingestion in the case of chewing gums.