Eating large quantities of meat has long been associated with manliness. Steak, bacon and burgers are seemingly tantamount to testosterone. But a new study published in the journal Fertility and Sterility on men’s fertility is turning that theory on its head. The study of couples seeking in vitro fertilization found that the higher a man’s consumption of processed meats such as cold cuts, bacon and sausage, the lower his sperm’s ability to fertilize an egg. More than 90 percent of male infertility is caused by low sperm counts, poor sperm quality or both.

There was no association found between men’s total meat consumption and the rate of successful fertilization through IVF, but the rate of fertilization was 13 percent higher among men who ate the most poultry compared with those who ate the least amount of poultry.

The success rates for bacon-abstainers might be because in general they have healthier diets, the researchers said. A third of all cases of infertility are due only to health problems experienced by the male partner. Some other factors that can affect male fertility include sexually transmitted diseases, birth defects, genetics and obesity. In addition, factors like stress, excessive exercise, drug and alcohol use, and exposure to toxins and pesticides can also also lower sperm count.

The good news is that many of these problems can be remedied with behavioral changes. Men can also take vitamins like folic acid and zinc. It can be tough for men to admit that they can’t help conceive, but finding the problem is the first step toward fixing it.

In the meantime, for men who are hoping to have a child, it may be best to cut out the cold cuts and keep the bacon on the backburner.