PEOPLE who live on vegetarian diets have slightly weaker bones than their meat-eating counterparts, Australian researchers said on Thursday.

A joint Australian-Vietnamese study of links between the bones and diet of more than 2,700 people found that vegetarians had bones five percent less dense than meat-eaters, said lead researcher Tuan Nguyen.

The issue was most pronounced in vegans, who excluded all animal products from their diet and whose bones were six per cent weaker, Nguyen said.

There was "practically no difference" between the bones of meat-eaters and ovolactovegetarians, who excluded meat and seafood but ate eggs and dairy products, he said.

"But the magnitude of the association is clinically insignificant," he added.

"Given the rising number of vegetarians, roughly five percent (of people) in western countries, and the widespread incidence of osteoporosis, the issue is worth resolving," he said.