The revision to the 2013 Australian Dietary Guidelines is underway. To make efficient use of resources, high-quality published systematic reviews are being used to update the evidence for the highest priority research questions where possible.
Information about the identification and mapping of existing systematic reviews is available on Reviewing the evidence.
Systematic reviews were screened against eligibility criteria below before being considered for inclusion in the revision. Eligible citations were checked to ensure that the studies have not been redacted. Redacted studies will be excluded.
Information about the identification and mapping of existing systematic reviews is available on Reviewing the evidence.
Systematic reviews were screened against eligibility criteria below before being considered for inclusion in the revision. Eligible citations were checked to ensure that the studies have not been redacted. Redacted studies will be excluded.
Broad research questions for highest priority topics
To be considered for use in the review, a systematic review must relate to one of the priority research questions. The prioritised research questions can be categorised according to 2 broad types of question:
- Diet and health outcomes: research questions that explore the relationship between different diets or eating behaviours and health outcomes; or
- Contextual factors: research questions that explore the relationship between contextual factors (for example, food security) and achievement of diets consistent with guideline recommendations.
Each research question comprises a population of interest, an intervention /exposure of interest, a comparator of interest, and one or more outcomes of interest. Collectively, these parameters are known as the ‘PI/ECO’ criteria.
The PI/ECO criteria for research questions focused on diet and health outcomes are listed at Table 1. PI/ECO criteria for research questions exploring contextual factors are listed at Table 2.
The Expert Committee advised that the research questions identified for the broader review remain relevant for older Australians. However, additional outcomes specific to older Australians were identified. These are included in Table 1 and 2.
To be eligible for consideration, systematic reviews must address the PI/ECO criteria listed in Table 1 or Table 2, including:
- one of the priority Intervention/Exposure and Comparison pairs (for example, high versus low intake of plant foods) OR contextual factors (for example, food security) AND
- at least one of the associated Populations (for example, children) AND
- at least one of the in-scope Outcomes (for example, child development).
| Populations At least one of the following: | Outcomes At least one of the following outcomes: | Intervention / Exposure and Comparison Pair At least one of the following: |
|---|---|---|
Includes:
AND/OR
AND/OR
Excludes populations exclusively selected on the basis of disease (e.g. diabetes, cardiovascular disease) | All populations:
Chronic condition risk factors
Healthy Aging
Outcomes prioritised for children and adolescents only:
Outcomes prioritised for pregnant & breastfeeding people only:
Breastfeeding specific outcomes
Birth outcomes
Outcomes in the infant/child
| Dietary patterns* and health outcomes:
Intake of animal vs plant sources of protein and health outcomes:
Ultra-processed food intake and health outcomes:
Meal patterns (eating behaviour) - Frequency of eating occasions and health outcomes:
Meats, poultry, fish, eggs, nuts and seeds, legumes/beans (including pulses and tofu):
|
* Dietary patterns must be relevant at a population level, for example Mediterranean diet, food patterns high in fat sources with high omega 3/PUFA/MUFA, plant-based diets.
Eligibility criteria for existing systematic reviews considered in the evidence review process
To be considered suitable for use, systematic reviews identified must:
- be a peer-reviewed systematic review (with or without a meta-analysis) of primary studies in humans
- address, or partially address, one or more of the priority research questions and its associated populations, interventions/exposures, comparators and outcomes
- have been published in the last 5 years (2018–2023), or 6 years (2018–2024) for older Australians evidence, with literature searches conducted no earlier than 1 January 2017
- be published in English (not translated)
- assessed and reported on quality or risk of bias of included studies, including identifying the tool used to assess each study design.
The following have been excluded:
- systematic reviews of nutritional supplements or nutrient-specific interventions. Nutritional (or dietary) supplements are products added to the diet, usually in the form of a pill, capsule, tablet, powder or liquid. They contain one or more dietary ingredients such as vitamins, minerals, herbs, amino acids and enzymes.
- systematic reviews addressing micronutrients
- systematic reviews of systematic reviews (also called umbrella reviews or overviews).
Eligible systematic reviews were mapped against the research questions above. This allowed the Expert Committee to consider options for addressing each priority research question and identify gaps in the underlying evidence base, that may be targeted by a commissioned review. The outcomes of the scoping and mapping work will be published on the NHMRC website when available.
