"There have been several reports linking red meat with increased risk of type 2 diabetes, and now the work of a number of research teams worldwide is showing this link for diabetes during pregnancy," says Ms Middleton, who is one of the Robinson Institute's research leaders.
"While this news is alarming, there are also some positives. The latest research from the United States has shown that eating fish and poultry does not increase the risk of gestational diabetes, and consuming more vegetable and non-meat protein is associated with a reduction in risk.
"For example, just over half a serving of nuts per day can reduce the risk of gestational diabetes by 40%."
Ms Middleton says although the link between red meat and diabetes is strengthening, scientists still don't understand the underlying mechanisms that cause it.
"More research is needed to better understand why this is happening and how to adapt women's diets and other lifestyle behaviors to prevent both gestational and type 2 diabetes," she says.
"Based on current evidence, pregnant women or women planning to become pregnant should consider eating more vegetable protein, and nuts, and replacing some red meat with fish and poultry.
"Midwives, dieticians and others involved in pregnancy care can help women to make these dietary changes in the hope of reducing poor outcomes for the mother and the baby," Ms Middleton says.
The full commentary can be found at the journal's website.