Draft Australian Dietary Guidelines (PDF, 3MB) - Eat For Health

seek evidence on the relationship between foods, dietary patterns and health outcomes. TheWorking Committee determined that the revised guidelines would be an evolution from theprevious versions and build upon their evidence and science base.In 2009, the Dietitians Association of Australia was commissioned through an open Request forTender process to systematically review the literature.The Working Committee, with the assistance of a NHMRC Guideline Assessment Register PanelConsultant, Ms Skye Newton of Adelaide Health Technology Assessment, developed 27 complexsearch questions for the literature review in areas emerging in the literature and areas included inthe 2003 Dietary Guidelines where the evidence base may have changed. A number of establishedfood, diet and health relationships covered in the 2003 Dietary Guidelines, where the evidencebase was unlikely to have changed substantially, were identified as not needing specific searchquestions to be asked. For example, the relationship between diets high in saturated fat andincreased risk of high cholesterol.The 27 search questions for the literature review were prioritised to 12 complex questions inconsideration of time and financial constraints. These formed the basis of questions for three typesof review: systematic literature review (the systematic review of the primary literature); umbrellareview (the systematic review of systematic reviews); and narrative reviews (the comprehensivereview of the literature to answer more qualitative questions, for example, such as that concerningnature and scope of international food guides and practices promoting food safety).The final questions for systematic and umbrella reviews were transcribed into PICO format.Detailed definitions and search terms were developed for each component of the final complexsearch questions and a number of specific search questions for each variable arising from variouspermutations were formulated for each complex question.Standardised processes were used to review the literature [34, 39-41]. Databases searchedincluded CINAHL, MEDLINE, DARE, Cochrane, ScienceDirect, PsychLit and ERIC. For eachspecific search question, the identified articles were retrieved and reviewed for relevance by ateam of reviewers. Papers published before 2002 were excluded. Duplicates, papers not within thescope of the search questions and papers that were already included in meta-analyses, describedcross-sectional studies or were not research studies (for example, letters and editorials) were alsoexcluded.The evidence was assessed according to NHMRC levels and grades for recommendations fordevelopers of guidelines [41] which allowed each article to be critically appraised and assigned a levelof evidence based on a hierarchy according to the type of research question. As this reviewlooked at causality and intervention research questions the following hierarchy was used:• Level I - A systematic review of level II studies• Level II - A randomised controlled trial• Level III-1 - A pseudorandomised controlled trialDRAFT Australian Dietary Guidelines- December 2011 158