Millions of couples are struggling to start a family. The Office of Women's Health says that around 10% of females up to age 44 have trouble getting or staying pregnant.

And male infertility affects 10% to 15% of men in the U.S. who are trying to conceive.

An increase in cases of sexually transmitted diseases and older average age of first time babymakers may account for some of the recent rise in cases of infertility.

But there's another cause that we should have seen coming: eating ultra-processed foods (UPFs).

A new study looked at data on 2,582 women ages 20-45 in the National Health and Nutrition Examination Survey. Just over 12% had experienced infertility.

And those women reported that their daily intake of UPFs totaled at least 31% of their diet.

UPFs interfere with fertility because they expose you to chemicals such as phthalates and BPAs that damage the body's ability to use nutrients essential for functional hormone levels and sexual reproduction — and they impair the immune system and energy metabolism.

In contrast, women who ate a Mediterranean diet (with fresh fruits and vegetables, healthy lean proteins such as fish, and olive oil) were far more likely to conceive and carry a healthy baby full term.

And men need to upgrade their diet too. In fact, both genders should take prenatal multivitamins for six months prior to conception because both parents’ nutrition before conception influences a child's lifelong health.

Want help upgrading your diet? Check out "What to Eat When" and the "What to Eat When Cookbook."