There's been a call for countries like New Zealand and Australia to reduce the amount of fatty foods they export to Pacific countries burdened by obesity.
Robert Scragg, an associate professor in Epidemiology at the Auckland University, is working on a large scale community obesity prevention project in four countries - Australia, Fiji, New Zealand and Tonga.
He says the limited range of good food available has added to the lack of physical exercise, to create overweight populations in places like Tonga.
The World Health Organisation's latest estimates say Nauru and Tonga have the highest incidence of obesity in the world, with nine out of every 10 adults overweight.
Mr Scragg says under World Trade Organisation agreements, Tonga can't lock out the fatty mutton flaps imported from New Zealand.
"We've jumped up and down and made a song and dance about French nuclear testing and what that's done to the health of the people in Tahiti but I think it's fair to say Australia and New Zealand have probably done more to damage the health of Pacific populations through the exporting of unhealthy food products like fatty mutton flaps."
Robert Scragg, an associate professor in Epidemiology at the Auckland University