We already know that too much Mickey Ds can make you fat and give you greasy skin and well, kill you – but now there’s another reason to skip the drive through and go for a healthy salad instead: research suggests it could lead to infertility later in life!

Via Vice:

Last spring, a group of Australian researchers published a study suggesting that the more fast food and generalized ‘junk’ that women eat, the more difficult it might be for them to get pregnant. In the study, 5,568 first-time mothers were asked to describe their diets in the month before they got knocked up, and eating garbage—our term, not the scientists’—seemed to affect how long it took them to conceive.

The women who “rarely or never” ate fast food had an 8% risk of infertility, while women who ate McMeals four or more times a week were twice as likely to experience periods of infertility. The frequent fast food eaters also took, on average, a month longer to get pregnant than women whose diets were ‘healthier.’

And sorry, dudes: It’s not just women. According to new research from Harvard University, eating trash food can affect your fertility, too. In this study, scientists assessed the “diet, semen quality, reproductive hormones, and lifestyle factors” of 2,935 Danish men who underwent medical exams before beginning their military service.

Men who had both the highest sperm count and the healthiest sperm followed [a healthy] diet, while the fewest and worst sperm were produced by those who went with that Western diet.

You might not be trying to get knocked up any time soon, but if you want kids in your future… it might be time to put down the burger, yo!