According to a clinical trial led by researchers at the University of Warwick and Queen Mary University of London, women who followed the diet benefited from a 35 per cent lower risk of developing diabetes in pregnancy.
The researchers also found that those following a Mediterranean diet during the antenatal period gained 1.25kg less weight on average compared to women consuming other diets.
The study, published in the journal PLOS Medicine and funded by Barts Charity, claims that the diet may also benefit pregnant women who suffer from a range of other health conditions, such as chronic hypertension or raised lipid levels.
More than 1,250 women were involved in the trial, all of whom were spread across five UK maternity units. As part of the diet, participants consumed 30g of mixed nuts a day in addition to 0.5 litres of extra virgin olive oil. They also received regular dietary advice throughout the course of their pregnancy.
Gestational diabetes is described by the NHS as high blood sugar that occurs during pregnancy. Symptoms may include tiredness, a dry mouth and increased thirst.
While it usually disappears after giving birth, gestational diabetes can cause health problems for the mother, such as polyhydramnios (this occurs when there is too much amniotic fluid in the womb and can prompt premature labour), pre-eclampsia (a condition that causes high blood pressure) and in rare cases, stillbirth.
Professor Shakila Thangaratinam, from Queen Mary University of London, said: “This is the first study to show that pregnant women at high risk of complications may benefit from a Mediterranean-style diet to reduce their weight gain and risk of gestational diabetes.
“Implementing this diet seems to be effective and acceptable to women.”
The professor notes that the current national dietary guidelines exclude key elements in the Mediterranean-style diet (such as consuming low levels of meat and dairy) in their recommendations.
Dr Thangaratinam adds: “Women who are at risk of gestational diabetes should be encouraged to take action early on in pregnancy, by consuming more nuts, olive oil, fruit and unrefined grains, while reducing their intake of animal fats and sugar.”
You can read more about gestational diabetes on the NHS website here.