The prime minister of Tonga has urged fellow leaders of Pacific nations to join the fight against obesity, proposing they all participate in a year-long weight loss challenge.

Akilisi Pohiva told the Samoa Observer he was going to propose the competition when the leaders meet at the Pacific Island Forum in Nauru next month.

“We should all get together for a weight loss competition for an entire year, so when we meet the following year we will weigh in again and see who has lost the most,” he said.

Pohiva pointed to the high rates of childhood obesity in Pacific nations as reason for concern.

Prime Minister of Tonga Akilisi Pohiva said he will suggest the weight loss challenge to other leaders next month. Photograph: Lukas Coch/AAP

“With Pacific Island leaders, we meet and talk and talk about this issue, yet initiatives on this issue [are] not making an impact, it doesn’t seem to work,” he said, adding pointedly: “But you see all the leaders ... no comment there.”

“Once the leaders are adapting to that mindset they would be determined to get their people on the same aspect and go from there,” Pohiva told the Samoa Observer.

More than 50% – and in some, up to 90% – of the population are overweight in at least 10 Pacific countries, according to the World Health Organisation.

In 2016, all 10 of the world’s most obese countries - by the adult prevalence rate – were Pacific island nations, according to the CIA World Factbook.

Nauru topped the list, with 61% of its adult population classified as obese (having a Body Mass Index of 30 or above). In six Pacific nations – Nauru, Cook Islands, Palau, Marshall Islands, Tuvalu and Niue – at least half of the adult population was obese.

Tonga ranked seventh in the world with 48.2% of the adult population classed as obese.

The replacement of traditional nutrient-rich food in favour of imported processed food has been blamed for the Pacific’s weight problem.