Researchers from Harvard University have discovered that men who eat more junk food have less healthy sperm and lower sperm counts.
The study, conducted by scientists from the Harvard TH Chan University of Public Health, took around 3,000 men aged between 18 and 20 and assessed their diet, as well as their sperm count.
They found that men who eat a 'western diet' that includes stuff like pizzas, processed meat, sugary snacks and fizzy drinks had worse quality sperm than men who eat healthily.
Put down the junk food. Credit: PA
Furthermore - and some of you aren't going to like this - men who eat a vegetarian diet had higher sperm counts, alongside those who eat a lot of fish and whole grains.
This is big news for us all, because - you might have noticed - we need sperm to keep the human race going. As diets have worsened over recent years, average sperm count has fallen by nearly 60 per cent.
That's a lot, and it ain't good news.
In a third of cases were a couple struggles to conceive, the problem is with the sperm. This is an issue that could easily be reversed or remedied if the man changes their diet.
The team from Harvard compared sperm counts of those without a decent diet who ate a lot of junk food, and those with a more balanced diet that includes fish, chicken, and vegetables or a more 'Scandinavian' diet that contains lots of cheese, milk, and grains.
Men who ate more of the bad stuff had 25.6m fewer sperm than those who didn't.
Seriously, we actually need sperm to survive. Credit: PA
According to the World Health Organisation (WHO) a regular sperm count should be somewhere around 39m sperm. That's a huge drop off.
The lead author of the study, Dr Jorge Chavarro, said: "We are seeing lower sperm counts and a few men fall below the WHO lower reference limits. This is the largest study to have found this in young men.
"You would be surprised to see how sensitive young men are to things that might affect sperm count, because it's a perceived measure of masculinity."
No, we wouldn't be surprised, Jorge.
Professor Allan Pacey, who is an andrology professor (that's someone who deals with diseases and conditions specific to blokes) at the University of Sheffield, told the Daily Mail: "This just shows the power of diet to the way that testicles function.
"It's almost certain that this is down to an effect that those with the better diets are taking more antioxidants.
"With pizza, chips and red meat we know that the antioxidant stress goes up and that is bad for sperm."
There you have it guys, if you want healthy sperm, you'll have to put down the pizza.
Featured Image Credit: PA