Trying to cure jet lag? Try chili, chocolate, and stretching.

• The Australian airline Qantas is conducting test flights to find a cure for jet lag on long flights.
• The airline is testing changes to in-flight menus, lighting, and exercise offerings for passengers.
• Menus with chili and chocolate help keep people awake, while light exercise helps travelers sleep better.

Planning a long-haul flight this summer? Researchers for the Australian airline Qantas are working to find a cure for jet lag — and the answer may be on your plate.

As part of ongoing research in partnership with the University of Sydney's Charles Perkins Centre, the airline conducted three non-stop 20-hour test flights from New York and London to Sydney, Australia, to study how passengers' reports of symptoms of jet lag (pesky brain fog, exhaustion or difficulty sleeping, as well as gastrointestinal problems) responded to changes made on board. 

The research, called "Project Sunrise," is being conducted ahead of Qantas launching direct flights along the same routes in 2025, a first, as no nonstop flight routes currently exist from either New York or London to Australia.

Qantas' goal is to aid travelers in overcoming jet lag and "to overcome the tyranny of distance between Australia and the rest of the world," Qantas Group CEO Alan Joyce said in a statement about the research.

Passengers aboard the test flights kept a daily log of their actions for the week before their trip, wore a device to track their movements, sleep, and light exposure while flying, then followed "a specially designed menu, lighting, sleep, and movement sequences," during the nonstop flights, according to the statement.

Participants also kept a log for two weeks after their trip to track how they felt throughout the study.

Lighting and meal services in the cabin were scheduled to mirror the destination time zone, and passengers participated in light stretches and exercises before sleep.

Menus offered on board "encouraged wake and sleep by using specific menu items including fish and chicken paired with fast-acting carbohydrates, as well as comfort foods like soups and milk-based desserts. The aim was to promote the brain's production of the amino acid tryptophan ('Tryp') to help passengers drift off more easily."

Insider previously reported eating tart cherries, watermelon, and cucumbers may help air passengers sleep and wake easier and fight jetlag.

The airline's team of 10 sleep experts, circadian researchers, and nutrition and movement specialists found that the adjusted lighting, sleep schedules — as well as meals featuring specific ingredients like chili and chocolate — during long-haul flights improved passenger's well-being by reducing their jet lag and giving them better sleep quality inflight.

The study found that participants also had better cognitive performance two days after their long-haul travel day.

"The early results are promising, and it's given us great momentum to look to the next stage of customer research to support Project Sunrise product and service design," Peter Cistulli, Professor of Sleep Medicine at the University of Sydney said in a Qantas statement about the research.

Cistulli added: "The early findings have given us optimism that we can make a real difference to the health and wellbeing of international travelers thanks to this partnership with Qantas." 

Representatives for Qantas and the University of Sydney's Charles Perkins Centre did not immediately respond to Insider's requests for comment.