Research topic areas of interest were identified through various scoping activities and prioritised by the Dietary Guidelines Expert Committee (Expert Committee). In summary the priority topics are:
- dietary patterns (combinations and amounts of foods regularly consumed)
- nutritional needs across the life course
- protein-rich foods (meats and poultry, fish, eggs, tofu, nuts and seeds and legumes/beans)
- ultra-processed foods.
Sustainable diets (accessible, affordable and equitable diets with low environmental impacts) were also identified as a very high priority. Sustainability is being addressed via a separate process.
For more detail on the highest priority topics for review, see the full list of research questions.
More information about the scoping activities, prioritisation process and research question development is available in the Prioritisation Process Report and the Prioritisation Process Report for Older Australians.
Reviewing the evidence
Highest priority topics
To make efficient use of limited project resources, the evidence for the highest priority topics for review will be updated using:
- recent, high-quality published systematic reviews where available
- a limited number of newly commissioned evidence reviews where important evidence gaps are identified.
1. Mapping of existing systematic reviews
Evidence mapping activities were completed to make effective use of resources and avoid duplication of existing quality research.
The evidence map identified where recent, high-quality published systematic reviews could be used to address the highest priority research questions.
Relevant systematic reviews were identified through:
- literature searches undertaken by an independent evidence reviewer for systematic reviews (targeted database searches and identification of reviews published by key international groups)
- two public calls for systematic reviews to address priority research questions for all age groups (2023) and older adults (2024).
Following this, the independent evidence reviewer screened the identified systematic reviews against eligibility criteria and mapped eligible reviews to the highest priority research questions.
The Expert Committee used the evidence map to identify:
- the ‘most relevant’ existing reviews (based on scope, currency and risk of bias) to use to update the evidence underpinning the 2013 Guidelines, with the aim of achieving good coverage across highest priority questions. Expert Committee members were not provided with identifying information about each review until the reviews had been selected for potential use.
- critical gaps in the evidence where new evidence reviews may be required.
To select existing systematic reviews for consideration in the evidence review process and identify key gaps for new evidence reviews, the Expert Committee considered a range of factors including:
- whether the identified existing systematic reviews are likely to be appropriate for the research question
- whether the identified systematic reviews are likely to be sufficiently methodologically robust that their findings can be relied upon to answer the research question
- the impact on public health and wellbeing
- the likelihood that the evidence-base has changed enough to change recommendations since the development of the 2013 Guidelines.
Due to finite project resources, only a limited number of new reviews may be commissioned to address gaps in the priority research questions. Any priority research questions that remain unaddressed will be noted as evidence gaps to inform future reviews.
2. New evidence reviews
As important evidence gaps remain, the Expert Committee has requested new evidence reviews be commissioned.
New evidence reviews on diet and health outcomes in all age groups are on:
- Dietary patterns and new diagnoses of anxiety and depression in all ages (including pre/post-natal depression during pregnancy and breastfeeding).
- Ultra-processed food (UPF) consumption in children and adolescents and new diagnoses of anxiety and depression, asthma, dietary allergies, and neurocognitive development.
- Dietary factors (dietary patterns, source of protein or UPF consumption) associated with maternal and birth outcomes during pregnancy and breastfeeding.
- UPF consumption and all-cause mortality and new diagnoses of cardiovascular events, type 2 diabetes, cancer and anxiety/depression in adults.
New evidence reviews in the older adult population will look at:
- Sarcopenia (aged-related muscle wasting) and consumption of protein-rich food.
- Neurocognitive conditions (including dementia and Alzheimer disease) and consumption of protein-rich food.
Research questions for new evidence review on diet and sustainability were developed by the Dietary Guidelines Sustainability Working Group with guidance from the Expert Committee. They will be scoping reviews to identify Australian studies on the:
- Environmental impact of consuming different dietary patterns, protein-rich foods and ultra-processed foods (UPFs)
- Implications of different dietary patterns on sociocultural acceptability, accessibility, equity, cost and affordability of food.
Read more about the new evidence reviews.
Lower priority topics
Pragmatic considerations partly contributed to decisions about priority including whether a topic could be partially or indirectly addressed by an alternative research question of higher priority.
The topic areas prioritised for review do not necessarily reflect the priority of the recommendations to be updated. There will be topics that are critical for national dietary guideline recommendations which have not been identified as being the highest priority during scoping and evidence mapping for review.
Topics identified as lower priority but still considered to be critical for dietary guideline recommendations will be considered using:
- existing evidence from the 2013 Guidelines where the evidence is not likely to have changed enough to change the recommendations since their release
- evidence reviews published by recognised international groups.