Can the Keto Diet Help Boost Fertility?

The ketogenic diet is all the rage these days among those who are looking to shed a substantial amount of weight quickly. Given that being overweight or obese can reduce your chances of getting pregnant or staying pregnant (having excess body fat is associated with a higher risk of miscarriage), overweight women who want to have a baby may be wondering if the keto diet could help them slim down and boost their fertility at the same time. The answer is a resounding “maybe.”

Keto for Fertility: The Potentially Good News

A ketogenic diet — which is high in fat, moderate in protein, and low in carbohydrates— puts your body into a natural metabolic state called ketosis. By dramatically reducing your intake of carbohydrates (its primary source of energy), your body is forced to become super efficient at burning fat for energy instead. Preliminary research suggests this shift can enhance weight loss temporarily, as well as help reduce systemic inflammation, which is important because “inflammation can reduce overall fertility,” says Kristin Kirkpatrick, RDN, a wellness nutrition services consultant at the Cleveland Clinic Wellness Institute in Ohio. What’s more, a properly followed ketogenic diet can help reduce levels of insulin and possibly better regulate levels of other reproductive hormones, including testosterone, luteinizing hormone (LH), and follicle stimulating hormone (FSH).

Diet Can Affect Body Weight, Hormones, and Ovulation

“Using a ketogenic diet to improve body weight can definitely help women who do not ovulate — release an egg — regularly, including those with polycystic ovary syndrome [PCOS],” explains Rashmi Kudesia, MD, a reproductive endocrinologist and infertility specialist at CCRM Houston. “If they lose 5 to 10 percent of their body weight, they may resume ovulating.” (For the record, PCOS, a metabolic and hormonal disorder, is a leading cause of infertility in women.)

Possible Benefits of Going Keto for Women With PCOS

In fact, some research suggests that besides helping women with PCOS lose weight, the ketogenic diet may help rebalance their hormones — and in some cases help women who had previous infertility problems become pregnant on their own. In a small study published in the September–October 2018 issue of the journal AACE Clinical Case Reports, researchers followed four overweight women with PCOS who were trying to conceive follow a ketogenic diet, monitoring their progress monthly. Within six months, all four women lost weight, ranging from 19 to 36 pounds, and resumed regular menstruation (they’d all had irregular periods before they started the diet). The kicker: Two of the women conceived spontaneously without requiring ovulation induction.

The Ketogenic Diet May Be Sperm-Friendly

Excess weight and a poor diet can affect men’s fertility, too. “The standard American diet, filled with refined carbohydrates and sugar, has been associated with poor sperm health, negatively impacting sperm motility, morphology [shape], and shape count,” notes Will Cole, a doctor of chiropractic and a functional medicine expert in Monroeville, Pennsylvania, and author of Ketotarian. (Even a super-fertile woman is going to have trouble getting pregnant if her partner doesn’t have enough good-quality sperm.) “Conversely, diets rich in healthy fats, like nuts, seeds, and omega fatty-acid-rich fish, have been shown to improve sperm health,” Dr. Cole adds.

Causes for Concern About Keto and Fertility

While a ketogenic diet may help a woman who wants to get pregnant drop pounds quickly, it would be best to use it “to kick-start a new health routine and lose weight” before trying to conceive, Dr. Kudesia says, because you don’t want your body to be in a state of ketosis around conception (or any part of pregnancy). Also, for a healthy conception and pregnancy, it’s important to eat enough nutrient-dense whole foods, rather than to restrict calories, Cole says. “Just because something is high fat and low carb or keto doesn’t mean it is necessarily healthy.”

Indeed, it can be hard to follow the keto diet in a healthy way, as many people eat foods high in saturated fat, such as butter and bacon, to stay in ketosis. Too much saturated fat can increase total cholesterol, which strains the heart, according to the American Heart Association. Not to mention, one of the health risks of keto is developing nutrient deficiencies, registered dietitians agree.

Eating Styles That Support Preconception and Pregnancy Health

For these reasons, Rachelle Mallik, RDN, who specializes in reproductive nutrition in Chicago, believes that following the Mediterranean diet or a so-called Dutch-style diet— which emphasizes fruits, vegetables, meats, fish, whole-wheat bread (and cereals), and healthy fats — is a better approach to preconception because it has a more balanced distribution of macronutrients. “Glucose (a form of carbs) is the primary source of fuel for a growing baby, so a balanced diet is important during pregnancy,” says Mallik.

Carbs Are Okay, Especially for Preconception

So there’s no good reason to play the how-low-can-you-go game with healthy carbohydrates, she says. In fact, research published in March 2017 in the journal Nutrients found that so-called low-carbohydrate diets — where less than 45 percent of the day’s total calories come from carbs (by contrast, a standard keto plan typically allows a maximum of 20 percent of calories to come from carbs) — can lead to improvements in reproductive hormone levels and regular ovulation in women who are overweight or obese.

Carbs Can Be Comforting and Counter Morning Sickness and Other Pregnancy Symptoms

Another concern: Adhering to a restrictive diet like the ketogenic plan could add to a woman’s stress while she’s having fertility treatments, or it could have a negative impact on her relationship with food, Mallik says. “To cope with nausea during pregnancy, women often reach for carbohydrates, like plain crackers or pretzels,” she notes. (By the way, for the latter reason, keto isn’t recommended for anyone with a history of eating disorders.) The keto plan would put those on the no-fly list; even if a woman has stopped the ketogenic diet by the time she’s pregnant, she may have a lingering sense that those foods aren’t good for her and feel guilty about eating them.