A leading Australian nutritionist has urged airlines to charge obese passengers more for their seats.
Insurance companies impose higher premiums on overweight clients
Dr John Tickell believes a "fat tax" would highlight his country's obesity crisis and make commercial sense, as heavier loads increase fuel costs.
But health groups have warned that to single out people with weight problems could cause them emotional stress.
Recent studies estimate that 67% of Australian men and over half of women aged over 25 are overweight or obese.
Experts have warned that by 2030 half of the country's children will be overweight or obese if the problem goes unchecked.
In March, Australian health officials were forced to equip their fleet of ambulances with heavy-duty stretchers to cope with the sharp rise in overweight patients.
Dr Tickell, a leading nutritionist and author, told the BBC that society should take a more hardline stance against obesity and get tough on fat airline passengers.
He said that Australian airlines should impose charges on their overweight clients, as they do for excess baggage, because heavier loads increase fuel costs.
"I fly Sydney to Perth - five hours - and being totally disadvantaged by some huge person next to me literally flopping over into my seat. Why should I pay the same as them?" he asked.
Dr Tickell said it was important to start highlighting Australia's obesity crisis.
"I think we're a bit too nice, we're a bit too precious about minority groups. I think the majority group must have something to say too," he added.
But the chief executive of the Australasian Society for the Study of Obesity, Dr Tim Gill, said penalty charges should not be imposed on overweight passengers.
"It's not fair to single out those people who have a problem, which is already impacting greatly on their life, and make them feel like pariahs," he said.
A spokesman for the Australian budget airline, Jetstar, said it had no plans to charge larger passengers more for their seats.
Airlines are, however, monitoring long-term trends in the size and shape of their customers, the BBC's Phil Mercer in Sydney says.