Dietary intake and nutritional status of children and adolescents in Europe.

The objective of this project was to collect and evaluate data on nutrient intake and status across Europe and to ascertain whether any trends could be identified. Surveys of dietary intake and status were collected from across Europe by literature search and personal contact with country experts. Surveys that satisfied a defined set of criteria -- published, based on individual intakes, post-1987, adequate information provided to enable its quality to be assessed, small age bands, data for sexes separated above 12 years, sample size over 25 and subjects representative of the population -- were selected for further analysis. In a small number of cases, where no other data for a country were available or where status data were given, exceptions were made. Seventy-nine surveys from 23 countries were included, and from them data on energy, protein, fats, carbohydrates, alcohol, vitamins, minerals and trace elements were collected and tabulated. Data on energy, protein, total fat and carbohydrate were given in a large number of surveys, but information was very limited for some micronutrients. No surveys gave information on fluid intake and insufficient gave data on food patterns to be of value to this project. A variety of collection methods were used, there was no consistency in the ages of children surveyed or the age cut-off points, but most surveys gave data for males and females separately at all ages. Just under half of the surveys were nationally representative and most of the remainder were regional. Only a small number of local surveys could be included. Apart from anthropometric measurements, status data were collected in only seven countries. Males had higher energy intakes than females, energy intake increased with age but levelled off in adolescent girls. Intakes of other nutrients generally related to energy intakes. Some north-south geographical trends were noted in fat and carbohydrate intakes, but these were not apparent for other nutrients. Some other trends between countries were noted, but there were also wide variations within countries. A number of validation studies have shown that misreporting is a major problem in dietary surveys of children and adolescents and so all the dietary data collected for this project should be interpreted and evaluated with caution. In addition, dietary studies rely on food composition tables for the conversion of food intake data to estimated nutrient intakes and each country uses a different set of food composition data which differ in definitions, analytical methods, units and modes of expression. This can make comparisons between countries difficult and inaccurate. Methods of measuring food intake are not standardised across Europe and intake data are generally poor, so there are uncertainties over the true nutrient intakes of children and adolescents across Europe. There are insufficient data on status to be able to be able to draw any conclusions about the nutritional quality of the diets of European children and adolescents.

PASSCLAIM - Diet-related cardiovascular disease.

Cardiovascular disease (CVD) has a multifactorial aetiology and many potential risk markers are known. As it was not feasible to discuss all markers and their possible interactions in relation to all aspects of CVD, selections had to be made in this paper. In the context of claims and functional foods, emphasis was placed on those aetiological processes and risk markers that have been shown previously to be modified by diet: lipid and lipoprotein metabolism, haemostatic function, oxidative damage, homocysteine metabolism, and blood pressure. Except for methodological and biological characteristics of these biomarkers, their relationships with the risk of CVD are discussed. For LDL and HDL cholesterol, fasting triacylglycerol, homocysteine, and blood pressure well-validated, easy applicable, and generally accepted biomarkers exist. For haemostatic function and oxidative damage validation of markers with respect to CVD or intermediate clinical markers is recommended. For diet-related CVD, however, the ultimate question is whether changes in the biomarker are truly related to changes in risk. Only for LDL cholesterol and blood pressure does consensus exist among scientists for a possible application as enhanced function claims. For HDL, triacylglycerol, and homocysteine, and in particular for haemostatic function and oxidative damage, however, formal proof is lacking that diet-induced changes in these biomarkers alter the risk of CVD. At the same time, it should be emphasised that CVD is multifactorial. Therefore it does not seem justified that a change in one particular biomarker is enough evidence to substantiate a claim. There are examples of food components or drugs that one biomarker is changed in a favourable way, but at the same time another biomarker is changed in an unfavourable way. Therefore, studies to further validate generic predictors for the CVD risk should be initiated.

PASSCLAIM - Bone health and osteoporosis.

BACKGROUND: The EC Concerted Action PASSCLAIM aims to produce a generic tool for assessing the scientific support for health-related claims for foods and food components. AIM: The task of the ITGB Working Group was to critically evaluate the categories of scientific evidence needed to support claims in relation to bone health and osteoporosis. METHODS: A framework was developed to describe the chain of evidence that is required to link the consumption of a food or food component to bone health outcomes. Techniques available for interrogating each link in the chain were identified and their strengths and weaknesses considered. This framework was used to determine intermediate markers of health outcome with respect to osteoporosis and to debate the level of evidence that would be required to substantiate claims of enhanced function or reduced disease risk. RESULTS: Use of this framework with osteoporotic fracture as the health endpoint resulted in the following judgements based on current knowledge: 1) bone mineral density (BMD) is an intermediate marker of bone health which, for people of any age and sex, can provide evidence of enhanced function; 2) for people over 50 years living in populations with a high incidence of fracture, BMD is an intermediate marker of osteoporotic fracture risk which can provide evidence of an increased probability of reduced disease risk; 3) because osteoporosis is defined as a state of increased fracture risk due to low bone mass and deterioration in bone microarchitecture, a claim of a definite reduction in osteoporosis or fracture risk requires similar substantiation to claims that fractures are prevented or treated, including clinical trials and animal studies; 4) data from lower in the chain of evidence, such as bone turnover and calcium bioavailability, are not, by themselves, sufficiently strongly related to bone health endpoints to provide evidence of enhanced function or reduced disease risk but can provide supporting information. CONCLUSIONS: In the light of existing scientific knowledge, a framework has been developed as a tool for considering the scientific support for claims relating to bone health and osteoporosis. To provide a working example, the framework has been used to assess the current position with osteoporotic fracture as the health endpoint. This experience will contribute to the formulation under PASSCLAIM of a generic tool for assessing the scientific support of health claims on foods.

PASSCLAIM - Physical performance and fitness.

OBJECTIVE: The aim of the EC Concerted Action PASSCLAIM was to develop a set of methods and procedures for assessing the scientific support for function-enhancing and health-related claims for foods and food components. This paper presents a critical review of the existing methods to evaluate the different aspects of physical performance and fitness needed to support claims on foods and food ingredients intended to enhance specific physiological functions. DESIGN AND RESULTS: Based on an inventory of labelling claims on available sport nutrition products, seven physiological functions in the field of physical performance and fitness were identified: 1) strength and power, 2) endurance, energy supply and recovery, 3) hydration/re-hydration, 4) flexibility, 5) tissue growth, 6) free radical scavenger capacity and 7) immune function. For each function the existing methodology was reviewed critically and judged on suitability to generate scientific support for physiological function claims on foods. CONCLUSIONS: A database of methods including advantages and disadvantages of use has been generated for considering the scientific support of claims on foods and food ingredients relating to physical performance and fitness. It will contribute to the formulations of guidelines for assessing the scientific support of enhanced function or reduced disease risk claims on foods.

PASSCLAIM - Synthesis and review of existing processes.

Several approaches to the use of health claims on foods have been made around the world, and the common theme is that any health claim will require scientific validation and substantiation. There is also broad consensus that any regulatory framework should protect the consumer, promote fair trade and encourage innovation in the food industry.This paper is based on a critical evaluation of existing international approaches to the scientific substantiation of health claims, with a view to identifying common new ideas, definitions, best practice and a methodology to underpin current and future developments. There is a clear need to have uniform understanding, terminology and description of types of nutrition and health claims. Two broad categories were defined: Nutrition Claims, i. e. what the product contains, and Health Claims, i. e. relating to health, well-being and/or performance, including well-established nutrient function claims, enhanced function claims and disease risk reduction claims. Such health claims relate to what the food or food components does or do. The categories of health claims are closely and progressively related and are, in practice, part of a continuum. Provision is also made for "generic" or well-established, generally accepted claims and for "innovative" or "product-specific" claims. Special attention was paid to reflect the health-promoting properties of a food or food component in such a way as to facilitate the making of risk reduction claims outside the medical scope of the term prevention. The paper sets out basic principles and guidelines for communication of health claims and principles of nutritional safety. The main body of the work examines the process for the assessment of scientific support for health claims on food and emphasises an evidence-based approach consisting of: Identification of all relevant studies exploring the collection of evidence, data searches, the nature of the scientific evidence, sources of scientific data (including human intervention studies, human observational studies, animal studies and in vitro studies, and the use of biomarkers in human studies. Evaluation of the quality of individual studies to ensure good experimental design and interpretation. Interpretation of the totality of evidence to apply scientific judgement to interpret the weight of evidence as a whole. Assessment of significant scientific agreement on a case-by-case basis to agree within the relevant scientific community that an association between a food or a food component and a health benefit is valid. Annexes include an international comparison of regulatory approaches to health claims, suggestions for the documentation and presentation of evidence, and a procedure for reviewing the evidence.

Energy and nutrient dietary reference values for children in Europe: methodological approaches and current nutritional recommendations.

The Expert Group on the Methodological Approaches and Current Nutritional Recommendations in Children and Adolescents was convened to consider the current situation across Europe with regard to dietary recommendations and reference values for children aged 2-18 years. Information was obtained for twenty-nine of the thirty-nine countries in Europe and a comprehensive compilation was made of the dietary recommendations current up to September 2002. This report presents a review of the concepts of dietary reference values and a comparison of the methodological approaches used in each country. Attention is drawn to the special considerations that are needed for establishing dietary reference values for children and adolescents. Tables are provided of the current dietary reference values for energy and for the macronutrients, vitamins, minerals, trace elements and water. Brief critiques are included to indicate the scientific foundations of the reference values for children and to offer, where possible, an explanation for the wide differences that exist between countries. This compilation demonstrated that there are considerable disparities in the perceived nutritional requirements of European children and adolescents. Although some of this diversity can be attributed to real physiological and environmental differences, most is due to differences in philosophy about the best methodological approach to use and in the way the theoretical approaches are applied. The report highlights the main methodological and technological issues that will need to be resolved before harmonization can be fully considered. Solving these issues may help to improve the quality and consistency of dietary reference values across Europe. However, there are also considerable scientific and political barriers that will need to be overcome and the question of whether harmonization of dietary reference values for children and adolescents is a desirable or achievable goal for Europe requires further consideration.

PASSCLAIM--body weight regulation, insulin sensitivity and diabetes risk.

BACKGROUND: Insulin sensitivity is a key function in human metabolism because it has a crucial role in the development of disease that are increasingly common in modern society. Impaired insulin sensitivity is an important determinant of type 2 diabetes; moreover, it has been proposed as an independent risk factor for cardiovascular disease. Thus, reduced insulin sensitivity is strongly associated with the metabolic syndrome, which represents a cluster of metabolic abnormalities and cardiovascular risk factor. Insulin sensitivity can be modulated by different environmental factors, including dietary habits. Obesity, especially if associated with abdominal adiposity, impairs insulin-sensitivity while physical activity can improve it; however, the composition of the habitual diet is clearly an important regulator of this function. AIM: To evaluate methodologies and markers that can be used to substantiate existing and potential claims of beneficial effects of foods on relevant functions connected with body fat deposition, insulin sensitivity and blood glucose regulation. RESULTS: We have reviewed the scientific basis for existing and potential claims, based not only on modifications of the target functions (body fat deposition, insulin sensitivity and blood glucose regulation) but also on modifications of other relevant associated functions (energy intake, energy expenditure, fat storage and oxidation, lipotoxicity, body fat composition, inflammation, oxidative stress, vascular function, glucose production and utilization). In this context we have identified a number of markers and evaluated appropriate method to measure and validate them. CONCLUSIONS: Relevant functions contributing to overweight, the metabolic syndrome and diabetes have been identified. The evidence reviewed indicates that in this field the link between nutrition, biological responses and diseases is clearly established. Therefore, there is a strong potential to develop functional food science. The major gap in the evidence continues to be the lack of diet based intervention trials of sufficient duration to be relevant for affecting the natural history of these conditions.

PASSCLAIM--mental state and performance.

BACKGROUND: The intake of food and drink can influence brain functions, which in turn may have effects on mental state and performance. Therefore, in principle claims to improve mood or specific aspects of cognitive performance by the consumption of functional foods are possible and indeed are currently found on the market. AIM: The paper reviews existing methodologies, which may be used to substantiate and validate such claims of desirable effects of foods on mental state and performance. RESULTS: Mood, arousal, activation, vigilance, attention, sleep, motivation, effort, perception, memory and intelligence have been identified as relevant aspects of mental state and performance. The basic scientific concepts within this field as well as the methodologies to measure these concepts have been reviewed and described. CONCLUSIONS: From this review it is concluded that, in principle, the phenomena in these fields are no different to those in other fields of life science. The scientific methods and protocols described in this report can positively demonstrate the effects of foods on mental state and performance in a scientifically valid way. A claim on mental state and performance like other claims must be based on scientific evidence. This report confirms that methodologies do exist to generate sound scientific evidence in this area. Therefore, claims on the enhancement of specific mental functions can and should be substantiated and validated using the methodologies described in this review.

PASSCLAIM--diet-related cancer.

BACKGROUND: The role of dietary factors in the aetiology of human cancer is an area, which has attracted intense interest in recent years. The suggestion that approximately one third of all cancers may be caused by an 'inappropriate' balance of food components has led to the attractive contention that we can significantly decrease cancer incidence through dietary recommendations and a change in dietary habits in populations. Thus, a key issue must be to establish clear criteria, which must be met in order to be able to make 'cancer risk reduction' claims for food components. In this area, the one true marker is the malignant human tumour, which for practical reasons is usually not accessible to claims. In its absence, we must rely on alternative markers--biomarkers/surrogate endpoints. This paper mainly deals with the link of these biomarkers to the endpoint tumour and their usefulness for making claims. Some claims have been made based on epidemiological studies. AIM: Can we identify targets/ biomarkers in the chain of events from initial 'exposure' to overt malignant tumour, whose modification can be used to make 'anticancer' claims for food components? RESULTS: We identified 18 targets/markers in the above chain of events whose modification 'have the potential' to be used for 'reduction of cancer risk' claims for food components. These targets/markers fall under 5 broad headings: tumours and preneoplastic changes; cellular targets/markers; gut luminal markers; angiogenesis and metastasis; carcinogen metabolising enzymes; genetic events. CONCLUSIONS: The strongest markers presently available are precancerous lesions (e. g. polyps or aberrant crypt foci) in humans and precancerous lesions and tumours in animal models. The only marker that presently can be used for a 'reduction of disease risk' claim (type B) for food components is 'polyp recurrence'. Type B claims cannot be made on the basis of results in animal models. All of the other biomarkers examined presently lack validation against the 'true endpoint', the tumour, and thus cannot be used for type B claims. 'Reduction of disease risk' claims in the area of 'diet-related cancer' should be based primarily on human intervention studies using relevant/acceptable endpoints. An important area for future research will be the validation of these surrogate endpoints.

PASSCLAIM--gut health and immunity.

BACKGROUND: The gut and immune system form a complex integrated structure that has evolved to provide effective digestion and defence against ingested toxins and pathogenic bacteria. However, great variation exists in what is considered normal healthy gut and immune function. Thus, whilst it is possible to measure many aspects of digestion and immunity, it is more difficult to interpret the benefits to individuals of variation within what is considered to be a normal range. Nevertheless, it is important to set standards for optimal function for use both by the consumer, industry and those concerned with the public health. The digestive tract is most frequently the object of functional and health claims and a large market already exists for gut-functional foods worldwide. AIM: To define normal function of the gut and immune system and describe available methods of measuring it. RESULTS: We have defined normal bowel habit and transit time, identified their role as risk factors for disease and how they may be measured. Similarly, we have tried to define what is a healthy gut flora in terms of the dominant genera and their metabolism and listed the many, varied and novel methods for determining these parameters. It has proved less easy to provide boundaries for what constitutes optimal or improved gastric emptying, gut motility, nutrient and water absorption and the function of organs such as the liver, gallbladder and pancreas. The many tests of these functions are described. We have discussed gastrointestinal well being. Sensations arising from the gut can be both pleasant and unpleasant. However, the characteristics of well being are ill defined and merge imperceptibly from acceptable to unacceptable, a state that is subjective. Nevertheless, we feel this is an important area for future work and method development. The immune system is even more difficult to make quantitative judgements about. When it is defective, then clinical problems ensure, but this is an uncommon state. The innate and adaptive immune systems work synergistically together and comprise many cellular and humoral factors. The adaptive system is extremely sophisticated and between the two arms of immunity there is great redundancy, which provides robust defences. New aspects of immune function are discovered regularly. It is not clear whether immune function can be "improved". Measuring aspects of immune function is possible but there is no one test that will define either the status or functional capacity of the immune system. Human studies are often limited by the ability to sample only blood or secretions such as saliva but it should be remembered that only 2% of lymphocytes circulate at any given time, which limits interpretation of data. We recommend assessing the functional capacity of the immune system by: measuring specific cell functions ex vivo. measuring in vivo responses to challenge, e. g. change in antibody in blood or response to antigens. determining the incidence and severity of infection in target populations during naturally occurring episodes or in response to attenuated pathogens.

Combined ingestion of protein and carbohydrate improves protein balance during ultra-endurance exercise.

The aims of this study were to compare different tracer methods to assess whole body protein turnover during 6 h of prolonged endurance exercise when carbohydrate was ingested throughout the exercise period and to investigate whether addition of protein can improve protein balance. Eight endurance-trained athletes were studied on two different occasions at rest (4 h), during 6 h of exercise at 50% of maximal O2 uptake (in sequential order: 2.5 h of cycling, 1 h of running, and 2.5 h of cycling), and during subsequent recovery (4 h). Subjects ingested carbohydrate (CHO trial; 0.7 g CHO.kg(-1.)h(-1)) or carbohydrate/protein beverages (CHO + PRO trial; 0.7 g CHO.kg(-1).h(-1) and 0.25 g PRO.kg(-1).h(-1)) at 30-min intervals during the entire study. Whole body protein metabolism was determined by infusion of L-[1-13C]leucine, L-[2H5]phenylalanine, and [15N2]urea tracers with sampling of blood and expired breath. Leucine oxidation increased from rest to exercise [27 +/- 2.5 vs. 74 +/- 8.8 (CHO) and 85 +/- 9.5 vs. 200 +/- 16.3 mg protein.kg(-1).h(-1) (CHO + PRO), P < 0.05], whereas phenylalanine oxidation and urea production did not increase with exercise. Whole body protein balance during exercise with carbohydrate ingestion was negative (-74 +/- 8.8, -17 +/- 1.1, and -72 +/- 5.7 mg protein.kg(-1).h(-1)) when L-[1-13C]leucine, L-[2H5]phenylalanine, and [15N2]urea, respectively, were used as tracers. Addition of protein to the carbohydrate drinks resulted in a positive or less-negative protein balance (-32 +/- 16.3, 165 +/- 4.6, and 151 +/- 13.4 mg protein.kg(-1).h(-1)) when L-[1-13C]leucine, L-[2H5]phenylalanine, and [15N2]urea, respectively, were used as tracers. We conclude that, even during 6 h of exhaustive exercise in trained athletes using carbohydrate supplements, net protein oxidation does not increase compared with the resting state and/or postexercise recovery. Combined ingestion of protein and carbohydrate improves net protein balance at rest as well as during exercise and postexercise recovery.