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Dengue fever is surging worldwide.

Dengue – the world’s most widespread mosquito-borne viral disease, causing an estimated 390 million infections annually across more than 100 countries – is surging in scale and severity. It is transmitted by Aedes mosquitoes, which thrive in urban water storage. In 2024, Brazil recorded nearly 5.8 million cases, seven times the number of Covid-19 infections in the same period, and there have been similar record outbreaks across Asia. The World Health Organisation now considers dengue one of the most important mosquito-borne diseases of humanity, with close to half the global population living in at-risk regions.

This wave has reached the Pacific: the most severe outbreak in a decade has claimed 19 lives, with Kiribati, Nauru, Samoa, and Tuvalu declaring emergencies. On Nauru, nine asylum seekers contracted dengue, including one man evacuated to Australia for treatment. Australia has pledged more than $1 million in emergency funding, including insecticides, test kits, and the deployment of an Australian Medical Assistance Team (AUSMAT) alongside a team from New Zealand. But is this the best approach?

While very hot regions may see transmission decline, cooler areas such as coastal and northern Australia could become more vulnerable.

Dengue has long flared across the Pacific in cycles tied to ecological and social disruption. It first spread around the region through colonial trade networks in the 19th century, and spread further during the Second World War as troop movements carried the virus across islands. In Australia, post-war infrastructure such as piped water and screened rainwater tanks eliminated dengue from Brisbane by the 1950s. Pacific Island states, by contrast, transitioned from colonisation to independence with fragile health systems and little investment in sanitation. Rapid urbanisation without adequate sanitation or piped water creates ideal breeding grounds. A single uncovered water tank can seed an epidemic.

A warming climate is playing a key role in dengue’s current resurgence. Anthropogenic climate change has already raised dengue incidence by an estimated 18% across Asia and the Americas, and some countries could face increases of up to 200% by mid-century. Some models predict that the global population at risk of dengue will rise from 53% in 2015 to 63% by 2080. The impact will not be uniform, however: while very hot regions may see transmission decline, cooler areas such as coastal and northern Australia could become more vulnerable. The Intergovernmental Panel on Climate Change has repeatedly warned that vector-borne diseases will proliferate in a warming world.

The hard truth is that there are few easy solutions. There is no effective cure for dengue, and vaccines remain limited in scope. Treatments manage symptoms rather than halt progression, while vector control methods, including insecticide spraying, genetic modification, and novel Wolbachia bacteria releases, are challenging and resource-intensive at scale.

In September, Australia’s $1 million pledge and Minister for International Development Anne Aly’s statement that the response was “backing the leadership and priorities of our Pacific neighbours”, signalled a rhetorical shift towards partnership. Programs such as PacMOSSI, launched in 2020, aim to build local capacity through training, laboratory support, and national dengue action plans. Yet choosing the right intervention is a challenge. Following the dengue outbreak in the offshore detention centre on Nauru, human rights organisations were critical of a lack of basic preventative and treatment measures such as mosquito nets and Panadol.

Protective clothing, repellents, and screened housing help at the individual and household level. More critical are reliable water and sanitation systems, combined with community action to eliminate mosquito breeding sites. Without such measures, external aid will always be chasing the next crisis rather than stopping it at the source.

Each outbreak, whether in Suva or Cairns, is a reminder of shared vulnerability in a warming world.

For Australia, dengue is both a health and a security concern. Northern Queensland still battles small outbreaks seeded by travellers, while in the Pacific the disease is becoming an arena of geopolitical competition. On the same day Canberra announced its aid package, China publicised its own shipments of medical supplies and vector-control equipment to Samoa, Tonga, Vanuatu, and Fiji. In Vanuatu the local health ministry and a Hong Kong-based foundation launched a two-year program to repress vector-borne diseases, a project linked to the Belt and Road Initiative. Australia’s traditional role as the region’s health partner is no longer uncontested.

Pacific leaders frame dengue as more than a health emergency: it symbolises the injustice of climate change. Island nations produce only 0.03% of global emissions, yet face rising seas and worsening climate-driven disease burdens. Australia’s emergency deployments are welcome, but they do not address the ecological and infrastructural conditions that allow dengue to thrive. If Australia limits itself to crisis response, it risks ceding influence and failing to reduce the long-term risk to itself. To truly compete, Australia must renew its climate commitments and support infrastructure that addresses the root drivers of transmission.

Each outbreak, whether in Suva or Cairns, is a reminder of shared vulnerability in a warming world. By aligning health aid with meaningful climate action and infrastructure development, Canberra can move beyond symptom management towards genuine prevention. Meeting this challenge requires more than emergency relief: it demands a sustained commitment to reducing carbon emissions, Pacific development, and resilience across the Indo-Pacific.

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A large national study reveals that sticking to an 11–12-hour eating window may promote longevity, while shorter or longer eating spans could quietly increase the risk of premature death.

Study: Association of Eating Window With Mortality Among US Adults: Insights From a Nationally Representative Study. Image Credit: Marcin Malicki / Shutterstock

In a recent paper published in the journal Aging Cell, researchers investigated the links between the duration of daily eating windows and mortality from various causes among American adults. They found a U-shaped association. Mortality risk was lowest for those with eating windows of 11–12 hours. Shorter (<8 hours) and longer (≥15 hours) eating windows were associated with higher mortality rates, although the latter showed weaker statistical significance after full adjustment for lifestyle and health factors.

Background

Time-based diets limit eating to certain hours and are popular for their simplicity and possible health benefits. Studies suggest that they improve glucose and lipid levels, boost ketone production, and reduce oxidative stress, thereby supporting better cardiometabolic health.

Most evidence comes from animal or short-term human studies, so we have limited knowledge about the long-term effects on longevity. Many studies focus on specific groups, like people with obesity, diabetes, or younger adults. This limits how widely results apply.

Evidence from U.S. surveys shows older adults tend to have earlier and narrower eating windows, particularly among women and Black individuals. While two recent studies based on the National Health and Nutrition Examination Survey (NHANES) suggested nonlinear associations between eating duration and mortality, they were limited by broad categories or specific age groups, which may obscure the risks associated with very short eating windows.

Mechanistic and observational studies suggest that very short eating windows can lead to nutrient deficiencies or insufficient energy intake, while excessively long ones encourage late-night eating and circadian disruption that impairs glucose tolerance and lipid metabolism. Together, these findings make nonlinear links between eating windows and mortality biologically plausible.

About the Study

Researchers employed a prospective cohort design, based on NHANES data from 2003 to 2018, and linked to mortality records through 2019. After excluding people younger than 20 and those with incomplete or invalid dietary recalls, extreme energy intake, pregnancy, missing demographic or health data, and outlying body mass index (BMI) values, 33,052 adults were included.

Dietary intake was assessed using two 24-hour recalls, and the eating window was defined as the time between the first and last intake of any caloric item within a day. Data from both recalls were averaged to account for daily variation. Mortality outcomes, including all-cause, cardiovascular, and cancer-related deaths, were obtained from the National Death Index.

Covariates included demographics, socioeconomic factors, lifestyle behaviors (smoking, alcohol use, physical activity, and sleep), diet quality (as measured by the Healthy Eating Index), and health status, including chronic conditions. BMI and weight-related perceptions were also taken into consideration.

Associations were examined using two complementary approaches: (1) restricted cubic splines to model nonlinear relationships (treating eating windows as continuous), and (2) predefined categories (e.g., <8h, 12–12.99h as reference, ≥15h). Analyses used survey-weighted Cox regression models to account for NHANES’ complex sampling design.

Key Findings

This study followed 33,052 American adults for a median of 8.1 years, documenting 4,158 deaths, including 1,277 from cardiovascular disease and 989 from cancer. A U-shaped association emerged between the daily eating window and all-cause mortality.

The lowest mortality risk was linked to an eating duration of 11–12 hours per day. Eating for less than 8 hours daily was consistently associated with higher all-cause mortality, showing a 34% greater risk compared to the reference group (12–12.99 hours).

Longer eating windows (15 hours or more) were also associated with a 25% increased risk of developing the condition. However, this association was statistically significant only in White participants and had a confidence interval (1.01–1.55), indicating borderline significance after full adjustment.

Subgroup analyses revealed critical nuances:

• Shorter windows (<8h) drove a ~50–70% increase in cardiovascular mortality among older adults, men, and White participants (HRs ~1.5–1.7).
• No significant mortality risk was observed for shorter windows in younger adults after full adjustment.
• Women showed elevated but statistically nonsignificant mortality risk with shorter windows (p = 0.132), while men retained significance (p = 0.049).
• For cancer mortality, short-window associations faded after full adjustment, with a marginal trend observed only in women. Cardiovascular mortality mirrored these findings, with the lowest risk at 11–12 hours and significantly higher risk for shorter windows, but no strong overall associations with longer windows except among Whites (HRs approaching ~1.5 in spline models).

Sensitivity analyses excluding early deaths, younger participants, and extreme eating patterns confirmed the robustness of these results.

Conclusions

The findings suggest that both very short (less than 8 hours) and very long (15 hours or more) eating windows may increase the risk of mortality. In comparison, a moderate eating duration of 11–12 hours daily is associated with the lowest risk. These results highlight the potential health risks of highly restricted eating patterns, particularly for older adults, men, and White individuals. However, they do not broadly condemn intermittent fasting, emphasizing instead that deviations from moderate windows carry demographic-specific risks.

Strengths of this study include its large, nationally representative cohort, long follow-up period, comprehensive adjustments for diet quality, chronic conditions, socioeconomic factors, and lifestyle behaviors, as well as dual analytical approaches (continuous/categorical). Multiple sensitivity analyses further supported robustness.

However, limitations include reliance on self-reported dietary recalls (only two 24-hour assessments), which may not fully capture habitual patterns; the observational design, which prevents causal inference; lack of data on circadian timing of food intake; and unmeasured confounders, such as shift work details.

In conclusion, moderate eating windows appear most favorable for long-term health, underscoring the need for personalized approaches that avoid extremes in time-restricted eating, especially for high-risk subgroups.