Research - This is why you will strive to get pregnant while still on a junk food diet

Professor Claire Roberts, who led the study, said: "The findings show that eating a good quality diet that includes fruit and minimising fast food consumption improves fertility and reduces the time it takes to get pregnant."

In the study, 5,598 women pregnant with their first child were interviewed about their diet, and how long it had taken them to become pregnant.

The analysis revealed that compared to women who ate fruit three or more times a day, women who ate less fruit took half a month longer to become pregnant.

Similarly, compared to women who rarely ate fast food, women who consumed fast food four or more times a week took nearly a month longer to become pregnant.

Dr Jessica Grieger, who also worked on the study, said: "We recommend that women who want to become pregnant should align their dietary intakes towards national dietary recommendations for pregnancy.

"Our data shows that frequent consumption of fast foods delays time to pregnancy."

Strangely, the researchers found that while fruit and fast foods affected time to pregnancy, intake of vegetables or fish did not.

The researchers now hope to identify the particular dietary patterns, rather than food groups, that may affect how long it takes women to become pregnant.