Australian children born via caesarean section have a greater risk of developing cardiovascular disease and are more likely to be overweight or obese, according to a new study.

The proportion of C-section births has risen from 18.5 per cent in 1990 to 36 per cent in 2019, and researchers are warning the procedure increases the risk of cardiovascular diseases and obesity for children.

The link was revealed in a review of data from the Longitudinal Study of Australian Children, conducted by James Cook University's Murtupuni Centre for Rural and Remote Health and the University of Queensland.

"Four out of six individual CVD (cardiovascular disease) risk components and the composite index of the five CVD risk components showed a positive association with C-section birth," JCU's Dr Yaqoot Fatima said in a statement.

"Our study also provided a direct relationship between C-section and increased overweight and obesity among children at 10-12 years of age."

UQ's Dr Tahmina Begum said C-section children may have increased health risks because they have a different microbial load to those born vaginally.

She said those born by caesarean do not receive the benefits of certain microbiota that other children receive when a mother's amniotic membrane ruptures during birth.

"This altered microbial ecosystem hampers the 'gut-brain axis' and releases some pathogenic toxins that cause metabolic damage," Dr Begum said.

She said it was also possible the fetal stress from physiological or pharmacological induction of labour during a C-section could also have an impact.

Caesarean sections are on track to be half of all births by 2045, Dr Fatima said, but the study results show the procedure should be limited.

"Growing rates of C-sections conducted for non-clinical reasons is a major public health concern that calls for a reduction in the rate of unnecessary C-sections and their associated human and economic costs," said Dr Begum.

Dr Fatima said about 26 per cent of Australian adult deaths in 2020 resulted from cardiovascular diseases, which could be tempered by reducing C-section births.

"Globally, the chronic disease spectrum of CVDs costs trillions due to health service-related expenditures and loss of economic productivity," she added.