Diet is key to the maintenance of health and crucial in the prevention and management of many diseases. Modified nutrient intake may become essential to prevent deficiency, optimise development and health or manage symptoms and disease progression. Adding to the complexity, disease and its treatment can also affect taste, appetite and ability to access and prepare foods. Coupled with this, individual requirements for energy, macronutrients and micronutrients are influenced by factors such as life stage (age, growth, pregnancy, etc.) and health status, which can affect the processes of consuming, digesting, absorbing, metabolising or excreting nutrients. First and foremost, dietary advice must be based on sound evidence if it is to achieve and maintain human health. Furthermore, the practice of nutrition and dietetics must integrate and apply the sciences of food, nutrition, biology, physiology, behaviour management, communication and must also recognise the context that society presents, including the plethora of often conflicting information on diet and health available via the internet and other media sources.

A new Position Paper (Hickson et al., 2024) from the Academy of Nutrition Sciences (ANS) provides a state-of-the-art summary of how evidence-based practice is used to inform nutrition interventions for individuals, with a particular emphasis on research evaluation and using examples taken from the treatment of existing, clinically diagnosed disease. It is the third in a series of papers by the ANS that describe the nature of the scientific evidence and frameworks that underpin nutrition recommendations for health. It builds on the first ANS Position Paper that focussed on how dietary recommendations are formulated for populations for the prevention of non-communicable diseases (Williams et al., 2021a) and the second ANS Position Paper that examined the evidence used to support health claims for specific foods (Ashwell et al., 2022). Editorials that summarise these Position Papers and their recommendations have also been published to widen dissemination (Stanner et al., 2022a, 2022b; Williams et al., 2021b, 2021c), as is the case here with this editorial summarising the ANS Position Paper in relation to nutrition interventions for individuals (Hickson et al., 2024).

CLINICAL PRACTICE GUIDELINES

A primary method through which research evidence is used to guide individualised nutrition interventions is the development of clinical practice guidelines, which are “systematically developed statements to assist practitioner and patient decisions about appropriate health care for specific clinical circumstances” (Institute of Medicine Committee to Advise the Public Health Service on Clinical Practice, 1990). Guidelines attempt to bridge the gap between research and clinical practice, guiding the practitioner and patient to implement treatments based on the best available evidence. Importantly, evidence-based practice recognises that research evidence is integrated with clinical expertise and patient preference, described as a ‘three-legged stool’ to emphasise that without one of these elements, evidence-based clinical decision-making collapses (Peterson et al., 2016). See Figure 1.

Of major importance to evidence-based nutrition and dietetic practice is the ability to critically appraise the quality and certainty of research evidence in terms of: (i) whether an appropriate study design has been used to answer the clinical question; (ii) the methodological quality of the study (i.e. specific aspects of the methods); and (iii) the overall quality and certainty of the evidence as a basis for deriving recommendations, by applying GRADE (GRADE, 2013) or a similar framework. The Position Paper provides examples of critical appraisal tools for use with different study designs, including tools to assess the risk of bias within the study.

There are a number of published guidelines that support the delivery of nutrition interventions by nutrition and dietetic professionals. The aim of a well-defined methodological process is to promote objectivity, transparency and reproducibility while minimising issues such as conflicts of interest. Examples include the Evidence Analysis Library (EAL) that is hosted and reviewed by the US Academy of Nutrition & Dietetics (Academy of Nutrition and Dietetics, 2022) and the Practice-based Evidence in Nutrition® (PEN), which is an online nutrition knowledge translation platform jointly managed by Dietitians of Canada, the British Dietetic Association and Dietitians Australia (Neale & Tapsell, 2019). The EAL and PEN illustrate different approaches in applying research evidence to individual clients, and the full Position Paper includes a useful table comparing the two clinical practice guideline development processes.

CHALLENGES IDENTIFIED

The Position Paper identifies several challenges that require attention. Perhaps the most obvious of these is that, in addition to the increasing quantity and quality of robustly performed research studies, there is an abundance of conflicting information and misinformation that has to be navigated from diverse sources, including non-qualified practitioners, social media influencers and celebrities, the proliferation of fad diets and health products, and the tendency to use sensational headlines to attract more clicks, views and sales. See Box 1 for a summary of the challenges identified in the Position Paper.

ACADEMY OF NUTRITION SCIENCES CONCLUSIONS AND RECOMMENDATIONS

A number of strengths are recognised in the progress made to date, including: (i) implementation of research through transparent guidelines; (ii) defined processes for the development of national and international guidelines; and (iii) developments and collaborations in the form of EAL and PEN.

To address the challenges identified in its Position Paper (Box 1), the ANS makes 10 consensus recommendations, addressed to three specific audiences. A summary of these 10 recommendations is provided in Boxes 2, 3, 4, but a detailed description of the recommendations, together with tools to support groups in the application of these (e.g. research glossary, list of critical appraisals etc) is available in the full paper (Hickson et al., 2024).