Overweight or single mums are more likely to breed chubby children, new Australian research has found.

A study published in the Medical Journal of Australia shows a mother's weight and marital status have more influence on childhood obesity than her parenting style.

The study found that family conflict, negative life events, and maternal depression were not likely to affect a child's tendency to become overweight or obese.

"We found that parenting style was not associated with childhood obesity," said lead author Dr Lisa Gibson, a psychologist with the Telethon Institute for Child Health Research in Perth.

"Previous indications of a link between poor family functioning and childhood obesity were based on studies without population-based data and without observations across a range of theoretically important factors."

But parenting practices regarding eating and exercise may play a role in childhood weight problems, Dr Gibson said.

"Children from single-parent families, particularly when there is a family history of obesity, may struggle to maintain a healthy weight in an obesogenic environment with restricted access to nutritious foods and adequate facilities for recreational exercise," she said.

"The association between children's weight, maternal BMI (body mass index) and family structure confirms the need to find ways of targeting prevention and intervention efforts for childhood obesity at families with overweight parents, particularly under-resourced single-parent families."