Airlines may be the surprise beneficiary of the popularity of weight loss drugs such as Wegovy and Mounjaro that could lower airlines’ fuel costs and increase profits.
Analysts from Wall Street investment bank Jefferies have calculated that if weight loss trends continued, a 10 per cent slimmer society could yield an average 4 per cent increase to the earnings per share among major US airlines.
”A slimmer society = lower fuel consumption,” equities analyst Sheila Kahyaoglu wrote. Fuel makes up 20-30 per cent of an airline’s cost, which is reflected in the price of the ticket.
Since 2022, the US adult obesity rate has declined to 37 per cent from around 40 per cent, as GLP-1 appetite and blood sugar regulator drugs reshape the population.
“With the drug now available in pill form and obesity rates falling, broader usage could have further implications for waistlines,” wrote Kahyaoglu, who noted that until GLP-1, passenger weight had been out of the control of many people.
Looking at airlines American, Delta, United and Southwest, her team has calculated that a 10 per cent US slimmer society would comprise a 2 per cent weight savings, which could trim fuel expenses of up to 1.5 per cent. This would add an average of 3.9 per cent in earnings per share across the four airlines.
Aviation company Honeywell estimates that every 450 grams of a plane’s weight, “including crew, passengers, baggage and the aircraft itself”, totals up to about $US10,000 ($14,436) in annual fuel costs on commercial aircraft.
Sydney-based Peter Harbison, chairman of GreenerAirlines.com, said that when the GLP-1 drugs were rolled out, there was an expectation once-obese customers could begin to travel, leading to an uptick in demand.
“Airlines had already factored in heavier passenger weight years ago,” he said.
“I think the drug’s impact would be marginal for the weight of aircraft in the short-to-medium term, given there are so many other variables,” Harbison said. “But if you were getting up to 1 per cent of the cost of the flight, it makes a difference.”
In Australia, only around 32 per cent of the population was obese in 2022, according to the ABS.
The reported use of the drugs in the US is higher as well, rising from 5.8 of US adults in early 2024 to 12.4 per cent today.
As of 2025, only around 2 per cent of Australians take Ozempic and similar GLP1 drugs, with nearly half of the doses purchased privately.
Swinburne University school of engineering department of aviation’s Salim Hijazeen cautioned that GLP1s could make only a scant difference.
“Generally, airlines would try and focus on fuel optimisation more than wanting to plan around what the potential health trends of the population are,” he said.
“It’s very unlikely that something like this could significantly impact the weight of the aircraft in terms of the passenger weight,” he said.
Jefferies’ analyst Kahyaoglu calculated her forecast by combining the weight of 178 passengers aboard a Boeing 737 Max 8, with the individuals’ average pre-Ozempic weight of 180 pounds (81.6 kg). Factoring in the number of people who take Ozempic and its impact, the same passengers were tallied at 178 pounds (80.7 kilos).
The former yielded a maximum take-off weight of 181,200 pounds vs 177,996 pounds – a difference of 3204 pounds.
Applying a rule of thumb that 1 per cent weight savings equates to 0.75 per cent of fuel efficiency, a 2 per cent improvement in aircraft weight is worth about 4 per cent to earnings per share, Kahyaoglu wrote.
Harbison noted that when Ozempic appeared on the market, there was speculation that newly slimmer people would be emboldened to travel more thanks to the drug’s use.
“The implication is that presumably even though they’ve lost a bit of weight, they’re still above average, thereby presumably pushing up the average [on planes],” Harbison said.
Qantas declined to comment. Jetstar and Virgin were contacted for comment.
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