Both obese men and women can face fertility problems unless they reduce their weight. Reducing weight as the first step can bring back their fertility.

• Obese men are more than three times as likely to have low sperm counts compared with their normal-weight peers. A study published in the journal Fertility and Sterility showed that the heaviest men were at triple the risk of having a low count of progressively motile sperms, those that swim forward in a straight line.

• Increased body fat can also contribute to lower testosterone levels and higher estrogen levels.

• Obese men were also 1.6 times more likely than overweight or normal-weight men to have a high percentage of abnormally shaped sperm.

• There is a trend toward increasing likelihood of erectile dysfunction with increasing BMI.

• Obesity is associated with a greater risk of impotence.

• Obesity is also associated with metabolic syndrome and polycystic ovarian disease (PCOD) in women and associated infertility.