Trying to conceive? Then you might want to keep your other half away from McDonald’s, as a new study reveals that too much junk food can render an otherwise healthy man infertile.

According to the research, a diet high in junk food damages sperm thanks to its high fat content.

Fertility doctors from America’s Harvard University and the University of Murcia, Spain, studied sperm from hundreds of men, aged between 18 and 22.

The volunteers were first assessed to ensure they were in optimum health and had no other problems that may affect their reproductive system.

They were then instructed to keep a record of their daily diet for several months before being reassessed.

The study found that those who gorged on high-fat foods such as biscuits, cakes, chocolate, crisps, takeaways and fried and processed foods, had poorer quality sperm than those on a nutritious daily diet.

Even if they were a healthy weight and regularly exercised, their sperm was found to be less likely to survive the journey to fertilise an egg.

Those with the highest intake of trans fats - the processed oils used by junk food companies as a cheap way to boost taste – were found to have the worst quality of sperm.

Researchers found that a diet rich in wholegrains, fish and plenty of vegetables produced the best quality sperm.

More fertility-boosting nutrients for men…

Vitamin B12: According to Men's Health magazine, Japanese research from the Yamaguchi University School of Medicine found 42 per cent of men taking a 1500mcg daily supplement showed improved in sperm count and motility.
Find it in… natural yoghurt, eggs, salmon, liver

Vitamin C: A study at the University of Texas found that vitamin C helps prevent sperm from clumping together and decreases abnormalities. Get your RDA of 1000mg from a diet rich in fruit and vegetables.
Find it in… raspberries, strawberries, oranges, asparagus, broccoli

Vitamin E: Tel Aviv University researchers found men who upped their intake by  200mg a day saw conception rates rise.
Find it in… Muesli, porridge, sweet potato, avocado

Fatty acids: Fatty acids boost sperm's ability to penetrate the egg. According ton the Journal of Reproduction and Fertility, low levels of fatty acids are linked with sperm abnormalities.
Find it in… Oily fish, nuts, seeds

Zinc: A minimum daily intake of 15mg of zinc is necessary to not only boost sperm count but to increase its swimming stamina, too.
Find it in… Pumpkin and sesame seeds, eggs, red meat