This study investigated how the belief systems and interests of policy actors shaped their framing of the causes and solutions to obesity and how this influenced policy recommendations.

Submissions to the Select Committee on Obesity Epidemic in Australia (SCOEA) were collected, and actors were classified according to their interests in commercial and non-commercial groups. A framework grounded in social constructionism was used to code frames and underlying belief systems. The SCOEA report was analysed to identify the representative distribution of belief systems in recommendations.

Australia.

None.

150 submissions were collected and analysed. 120 submitters were actors with non-commercial interests, including governments (n 13), non-government organisations (n 49), civil society groups and citizens (n 24) and academia (n 34). Thirty submitters were actors with commercial interests including food industry representatives (n 23) and health enterprises (n 7). Conflicting belief systems in the framing of obesity were identified among policy actors, particularly between commercial and non-commercial groups. Non-commercial actors framed obesity in biomedical, lifestyle and socio-ecological terms, whereas commercial actors exclusively framed obesity as an issue of individual choices and proposed behavioural change interventions. A broad range of belief systems expressed by the submitters was represented in the SCOEA final report.

These findings illustrate how policy actors’ beliefs and interests shaped their frames and influenced the development of a key policy report. Policymakers seeking to advance obesity prevention policy must critically evaluate strategic framing by various actors and ensure that policy decisions are evidence-based and aligned with health, equity and ecological perspectives.

Ultra-processed beverages (UPB) have known adverse impacts on health, but their impact on the environment is not well understood across different environmental indicators. This study aimed to quantify the environmental impacts of water-based UPB and bottled waters sold in Australia and assess the impacts of various scenarios which may reduce such impacts in the future.

This study presents a quantitative environmental impact assessment of a major sub-category of UPB (water-based UPB, including soft drinks, energy drinks, cordials and fruit drinks) and non-UPB (bottled waters) in Australia. Alternative mitigation scenarios based on existing health and environmental targets were also modelled using sales projections for 2027. Sales data from Euromonitor International were matched with environmental impact data from peer-reviewed lifecycle assessment databases. Environmental impact indicators included greenhouse gas emissions, land use, eutrophication potential, acidification potential, water scarcity and plastic use.

The Australian beverage supply in 2022 and projected sales for 2027.

N/A

Environmental impacts of UPB were higher than bottled waters. UPB accounted for 81–99 % of total environmental impacts, partly driven by the volume of sales. Reformulation, reducing UPB consumption and increasing recycling all led to meaningful reductions in environmental impacts but with diverse effects across different environmental indicators. The largest reductions occurred when policy scenarios were combined to represent a suite of policy actions which aimed to meet health and environmental targets (30–82 % environmental savings).

The results indicate that implementing a suite of policies which act to target multiple drivers of environmental harm are likely to lead to the most environmental benefits.

Despite commitment by many countries to promote food system transformation, Australia has yet to adopt a national food policy. This study aimed to evaluate Australian Federal Government’s (AFG) food policies and policy actions potential to promote healthy and sustainable food systems.

This study is a desk-based policy mapping followed by a theoretically guided evaluation of policy actions. This involved three steps: (1) identification of government departments and agencies that could influence Australia’s food system; (2) identification of food policies and policy actions within these departments and (3) use of a conceptual framework to evaluate policy actions’ potential of changing the food system as adjust (first-order change), reform (second-order change) or transform (third-order change).

Australia.

None.

Twenty-four food policies and sixty-two policy actions were identified across eight AFG departments and the Food Regulation System and evaluated based on the order of change they represented. Most policies were led by individual departments, reflecting the absence of a joined-up approach to food policy in Australia. Most policy actions (n 25/ 56·5 %) were evaluated as having adjust potential, whereas no transformative policy action was identified.

These findings suggest that Australia is likely to proceed incrementally towards achieving food system change through adjustments and reforms but lacking transformative impact. To promote transformative change, all three orders of change must be strategically implemented in a coherent and coordinated matter. A comprehensive national food policy and a national coordinating body are needed to ensure a cohesive approach to policy.

Neuronal dysfunction of the locus coeruleus (LC), the primary producer of norepinephrine, has been identified as a biomarker of early Alzheimer's disease (AD) pathophysiology. Norepinephrine has been implicated in attentional control, and its reduced cortical circulation in AD may be associated with selective attentional difficulties. Additionally, greater pupil dilation indicates greater effort needed to perform a cognitive task, and greater compensatory effort to perform the digit span task has been found in individuals at risk for AD. In this study, we examined associations between a neuroimaging biomarker of the LC and pupil dilation during the Stroop task as a sensitive measure of attentional control.

64 older adults without dementia were recruited from the San Diego community (mean [SD] age = 74.3 [6.3]; 39 cognitively unimpaired and 25 with mild cognitive impairment). All participants underwent magnetic resonance imaging of the LC and generated behavioral data from a computerized Stroop task that included 36 incongruent trials (e.g., GREEN presented in red ink), 36 congruent trials (e.g., GREEN presented in green ink), and 32 neutral trials (e.g., LEGAL presented in green ink) in a randomized presentation. Mean pupil dilation for each trial (change relative to baseline at the start of each trial) was measured at 30 Hz using the Tobii X2-30 system (Tobii, Stockholm, Sweden) and averaged within each Stroop condition. Paired t-tests assessed for differences in mean pupil dilation across incongruent and congruent Stroop conditions. Iterative re-weighted least squares regression was used to assess the association between a rostral LC contrast ratio measure derived from manually marked ROIs and mean pupil dilation during incongruent trials divided by congruent trials, adjusting for age, sex, and education. Follow-up analyses also assessed the association of these variables with mean reaction time (RT) for incongruent trials divided by congruent trials.

Mean pupil dilation significantly differed across conditions (t = 3.74, mean difference = .13, 95% CI [.06, .20]) such that dilation was higher during the incongruent condition (mean [SD] dilation = .18 [.38] mm) relative to the congruent condition (mean [SD] dilation = .05 [.35] mm). A significant association was observed between pupil dilation and LC contrast ratio, such that increased levels of mean dilation during incongruent trials relative to congruent trials were observed at lower levels of LC contrast ratio (i.e., lower LC integrity; r = -.37, 95% CI [-.55, -.13]). This association was not observed for mean dilation during only congruent trials (r = -.08, 95% CI [-.31, .18]). Additionally, neither LC contrast ratio [r = .24, 95% CI [-.02, .46]) nor mean incongruent/congruent pupil dilation (r = .14, 95% CI [-.13, .37]) were associated with incongruent/congruent RT.

Findings suggest that increased pupil dilation during a demanding attentional task is indicative of increased compensatory effort needed to achieve the same level of performance for individuals with reduced LC biomarker integrity. Pupillometry assessment offers a low-cost, non-invasive, and scalable biomarker of LC dysfunction that may be indicative of preclinical AD.

The locus coeruleus (LC) plays a key role in cognitive processes such as attention, executive function, and memory. The LC has been identified as an early site of tau accumulation in Alzheimer’s disease (AD). LC neurons are thought to survive, albeit with limited functionality, until later stages of the disease, though how exactly this limited functionality impacts cognition through the course of AD is still poorly understood. We investigated the interactive effects of an imaging biomarker of the LC and AD-related cerebrospinal fluid (CSF) biomarkers on attention, executive function, and memory.

We recruited 67 older adults from the San Diego community (mean age=74.52 years; 38 cognitively normal, 23 with mild cognitive impairment, and 6 with probable AD). Participants had LC-sensitive magnetic resonance imaging (MRI) used to obtain a measure of LC signal relative to surrounding tissue, with lower LC signal possibly indicating limited functionality. Participants also underwent a lumbar puncture to obtain CSF measurements of amyloid-beta 42 (Ab42) and phosphorylated tau (p-tau). We calculated the p-tau/Ab42 ratio, which is positively correlated with AD progression. Finally, participants were administered a comprehensive neuropsychological battery, and cognitive composites were created for attention (Digit Symbol, Digit Span Forward, Trails A), executive function (Digit Span Backward, Trails B, Color-Word Inhibition Switching), and two measures of verbal memory [learning (CVLT List A 1-5, Logical Memory Immediate Recall) and delay (CVLT Long Free Recall, Logical Memory Delayed Recall)]. Four multiple linear regressions modeled the relationship between each composite with age, gender, education, p-tau/Ab42, average LC contrast, and interactions between average LC contrast and p-tau/Ab42. For models that were statistically significant, additional regressions were assessed to determine which segment of the LC (caudal, middle, rostral) contributed to the relationship.

Our model predicted attention (p=.001, R2=.298) with main effects of average LC signal, p-tau/Ab42, and LC by p-tau/Ab42 interaction. Follow-up regressions revealed that each LC segment contributes to this relationship. Our model predicted executive function (p=.006, R2=.262) with a main effect of average LC signal and LC by p-tau/Ab42 interaction. Follow-up regressions revealed that this relationship was limited to the caudal and middle LC. Our models predicted both verbal learning (p<.001, R2=.512) and delayed memory (p<.001, R2=.364); both with main effects of gender and education. Follow-up regressions revealed that the rostral LC signal interacts with p-tau/Ab42 to predict both verbal learning and delayed memory. For all interactions, those with low p-tau/Ab42 exhibited a positive relationship between LC signal and cognition, whereas those with higher p-tau/Ab42 showed a negative relationship.

MR-assessed LC signal relates to attention, executive function, and verbal learning and memory in a manner that depends on CSF levels of p-tau and Ab42. The relationship between LC signal and cognition is positive at low levels and negative at higher levels of p-tau/Ab42. If lower LC signal indicates reduced integrity, these findings imply that MR-assessed LC signal may be a more meaningful marker of AD progression in earlier stages of the disease. Alternatively, this measure may capture a different underlying mechanism depending on tau and amyloid biomarker status.