Food & health forum meeting: evidence-based nutrition

The essentiality of nutrients: a challenge to methodological monism in the scientific substantiation of health claims

This paper analyzes the way in which the EFSA has addressed the limitations that the essentiality of nutrients presents to the requirement of obtaining evidence from RCTs for the scientific substantiation of health claims. By redefining the requirements to affirm causality in the case of essentiality of nutrients, the EFSA has constrained the debate on the relevance of different methodologies in the field of nutrition research. However, avoiding this methodological debate does not settle the controversy as to whether the EFSA's evidentiary hierarchy is the best for both investigating causal relationships in nutrition and for achieving social objectives such as fostering innovation and public health.

Eating frequency and weight and body composition: a systematic review of observational studies

Objective

The present review aimed to examine the association of eating frequency with body weight or body composition in adults of both sexes.

Design

PubMed, EMBASE and Scopus databases were searched. PRISMA and MOOSE protocols were followed. Observational studies published up to August 2016 were included. The methodological quality of the studies was assessed with the Downs and Black checklist.

Setting

A systematic review of the literature.

Subjects

Adults (n 136 052); the majority of studies were developed in the USA and Europe.

Results

Thirty-one articles were included in the review: two prospective and twenty-nine cross-sectional studies. Thirteen per cent of the studies received quality scores above 80 %. The assessment of eating frequency and body composition or body weight varied widely across the studies. Potential confounders were included in 73 % of the studies. Fourteen studies reported an inverse association between eating frequency and body weight or body composition, and seven studies found a positive association. The majority of studies applied multiple analyses adjusted for potential confounders, such as sex, age, education, income, smoking, physical activity and alcohol intake. Six studies took into account under-reporting of eating frequency and/or energy intake in the analysis, and one investigated the mediation effect of energy intake.

Conclusions

There is not sufficient evidence confirming the association between eating frequency and body weight or body composition when misreporting bias is taken into account. However, in men, a potential protective effect of high eating frequency was observed on BMI and visceral obesity.

The role of metabonomics as a tool for augmenting nutritional information in epidemiological studies

Most chronic diseases have been demonstrated to have a link to nutrition. Within food and nutritional research there is a major driver to understand the relationship between diet and disease in order to improve health of individuals. However, the lack of accurate dietary intake assessment in free-living populations, makes accurate estimation of how diet is associated with disease risk difficulty. Thus, there is a pressing need to find solutions to the inaccuracy of dietary reporting. Metabolic profiling of urine or plasma can provide an unbiased approach to characterizing dietary intake and various high-throughput analytical platforms have been used in order to implement targeted and nontargeted assays in nutritional clinical trials and nutritional epidemiology studies. This review describes first the challenges presented in interpreting the relationship between diet and health within individual and epidemiological frameworks. Second, we aim to explore how metabonomics can benefit different types of nutritional studies and discuss the critical importance of selecting appropriate analytical techniques in these studies. Third, we propose a strategy capable of providing accurate assessment of food intake within an epidemiological framework in order establish accurate associations between diet and health.

Functional food and diabetes: a natural way in diabetes prevention?

Diabetes shows a wide range of variation in prevalence around the world and it is expected to affect 300 million by the year 2025. In a prevention framework where banning policies and educational strategies lead the interventions, functional foods (FFs) with their specific health effects could, in the future, indicate a new mode of thinking about the relationships between food and health in everyday life. Functional ingredients, such as stevioside, cinnamon, bitter melon, garlic and onion, ginseng, Gymnema sylvestre and fenugreek, have been addressed for their specific actions towards different reactions involved in diabetes development. New strategies involving the use of FF should be validated through large-scale population trials, considering validated surrogate end points to evaluate the effect of FF in prevention of chronic diseases such as type 2 diabetes mellitus.

Preparing dossiers: strength of the evidence and problems of proof

In Europe, for authorisation of a health claim, applicants must follow the procedures in the legislation and in the guidelines for submission of a dossier set out by the European Food Safety Authority. The Functional Foods in Europe (FUFOSE) and Process for the Assessment of Scientific Support for Claims on Foods (PASSCLAIM) projects underpinned the laws and provided criteria against which the quality of the totality of the available data could be judged. Whereas the regulations and PASSCLAIM require an assessment of the extent to which cause and effect can be demonstrated between a food category, a food or constituent and a health benefit, the European Food Safety Authority requires conclusive evidence of cause and effect. This latter standard of proof and a focus on randomised controlled trials done on isolated components and using validated physiological biomarkers may not always be appropriate to assess nutrition science. The aims of this paper are to address the strengths and weaknesses of different sources of evidence that contribute to the totality of the available data, to undertake a critical examination of the application of a drug-like assessment model in evidence-based nutrition and to encourage research on new biomarkers of health and homeostatic adaptability. There is a need for (a) a robust and pragmatic scientific framework for assessing the strength, consistency and biological plausibility of the evidence, and (b) consumer understanding research on claims that use qualifying language and/or graphics to reflect the weight of evidence. Such scientific, policy and communication approaches are proportionate and could help stimulate academic research, promote fair trade and product innovation and contribute to consumer education about food and health.