Too much tofu could affect a man’s fertility, scientists warn.

Researchers have found that eating even a modest amount of soya products – which are popular with vegetarians – could significantly lower your sperm count.

Men who ate an average of half a serving of soya food a day had lower concentrations of sperm than those who did not, the study found. And for those who were overweight or obese, the effects were more pronounced.

Low sperm count is known to make it harder for a man to conceive.

It is thought that soya compounds called isoflavones, which mimic the female sex hormone oestrogen, are behind the effect. Animal studies have linked a high consumption of isoflavones with infertility.