Overweight and obese women are more likely to have difficulty becoming pregnant. Approximately 63 percent of U.S. women are overweight or obese [source: Science Daily]. With that in mind, it would seem to make sense that women seeking to get pregnant should consume milk that is low in fat. But Harvard researchers have found that women who consume low-fat dairy two times each day are far more likely to experience infertility issues associated with ovulation than women who rarely eat or drink dairy. In fact, they had an 85 percent greater chance of experiencing ovulation problems than women who said they only consumed low-fat dairy once every week at the most [source: Medical News Today].
It's unclear why low-fat dairy appears to adversely affect fertility, but several theories exist. There's reason to believe that some of the substances that may be responsible for increased fertility rates among full-fat consumers are removed when low-fat milk is processed. Low-fat milk additives could also be to blame.
Whey is often added to low-fat milk to make it more visually appealing and to give the product a better taste. Unfortunately whey protein may influence a body in the same way testosterone does. Tests involving mice and whey consumption have led to that conclusion. If that's, in fact, the case, then low-fat milk may actually lead to a hormonal imbalance in women that's associated with infertility [source: Medical News Today].
Even so, researchers suggest that women who have become pregnant while consuming full-fat dairy products should resume their intake of low-fat dairy once they are expecting to minimize saturated fat in their diet [source: Medical News Today].
There are countless components of fertility ranging from a woman's weight to hormonal imbalances to healthy diet and age. The affect of dairy is becoming clearer, although it's a focus of continued research.