Eating plenty of fruit could help women conceive, a new study suggests.

Researchers who looked at more than 5,500 women from Britain, Ireland, Australia and New Zealand found those who consumed the least fruit were 50 per cent more likely to be infertile.

And compared to women who ate fruit three or more times a day in the month before conception, women who ate fruit less than one to three times a month took half a month longer to become pregnant.

Similarly, compared to women who never or rarely ate fast food, women who consumed fast food four or more times a week took nearly a month longer to become pregnant. Their risk of infertility also doubled from eight to 16 per cent.

However the amount of green leafy vegetables and fish made no difference to conception times.

Professor Claire Roberts, of the University of Adelaide, Australia, who led the study, said: "These 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."