The ketogenic diet, characterized by high fat, moderate protein, and very low carbohydrate intake, has gained immense popularity as a weight-loss strategy. Given the established link between healthy weight and fertility, many individuals and couples are exploring the keto diet as a potential tool to enhance their chances of conception. This article delves into the success stories surrounding keto and fertility, examines the available data, and addresses potential concerns.
Understanding the Keto Diet
The standard ketogenic diet involves consuming a high proportion of fat (around 75% of calories), a moderate amount of protein (20%), and a very limited amount of carbohydrates (5%). This drastic reduction in carbohydrate intake forces the body into a metabolic state called ketosis, where it begins to burn fat for fuel instead of glucose. This metabolic shift can lead to weight loss and reduced inflammation, both of which can positively influence fertility.
Anecdotal Success Stories
Online forums and communities are filled with anecdotal accounts of individuals who have experienced fertility success while following a keto or low-carb diet. Here are a few examples drawn from online discussions:
- One woman reported getting pregnant twice "almost immediately" on keto after years of trying and miscarriages. She is now pregnant with her fifth child while maintaining a keto/low-carb lifestyle.
- Another individual shared that it took nine months to conceive their first child. For their second pregnancy, they were on keto to lose weight from the first baby and conceived on their first try. They believe the diet boosted their fertility.
- One woman, not specifically on keto but having lost 50 pounds recently, attributed her pregnancy to the weight loss.
- Another woman, after cutting out dairy in November 2020 and carbs in February, got pregnant. To conceive her son, it took a loss, 2.5 years, and fertility meds.
These stories suggest a potential link between keto/low-carb diets and improved fertility, but it's crucial to remember that anecdotal evidence is not a substitute for scientific research.
The Science Behind Keto and Fertility
While anecdotal evidence can be encouraging, it's essential to examine the scientific data to determine the true impact of the keto diet on fertility.
Read also: Easy Low-Carb Cheese Crackers
Limited Data
Despite the growing popularity of the keto diet, scientific research on its effects on fertility is still limited. A search of PubMed, a database of biomedical literature, reveals only a handful of studies specifically investigating the relationship between ketogenic diets and fertility.
PCOS Studies
Polycystic Ovary Syndrome (PCOS) is a common hormonal disorder affecting women, often associated with infertility. Some studies have explored the effects of the keto diet on women with PCOS.
- A pilot study in 2005 found that women with PCOS who followed a ketogenic diet for 24 weeks experienced significant reductions in body weight, testosterone levels, and insulin levels.
- A later study in 2020, women with PCOS who adhered to a 12-week Mediterranean-based ketogenic diet experienced improvements in hormonal and metabolic markers.
These studies suggest that the keto diet may have potential benefits for women with PCOS by improving hormone balance and metabolic health. However, the small sample sizes of these studies limit the ability to draw definitive conclusions.
Impact on IVF Outcomes
A recent study published in Nutrients investigated the impact of a very-low-calorie ketogenic diet (VLCKD) on in vitro fertilization (IVF) outcomes in women with PCOS and high body mass. The study found that patients on the VLCKD lost significant weight, reduced hip and abdominal circumference, and improved metabolic health markers compared to those on a Mediterranean diet (MD). Additionally, the number of new cases of ovarian hyperstimulation syndrome (OHSS) was lower in the VLCKD group. The study concluded that VLCKD appears to improve reproductive health and promote safer IVF.
Weight Loss and Fertility
One potential mechanism by which the keto diet may improve fertility is through weight loss. Studies have shown that even a modest weight loss of 5-10% can significantly improve hormonal imbalances and reduce the risk of miscarriage. Since the keto diet can be effective for weight loss, it may indirectly contribute to improved fertility outcomes.
Read also: Keto Calorie Counting: A Detailed Guide
Male Fertility
Excess weight and poor diet can also affect men’s fertility. A diet high in refined carbohydrates and sugar has been associated with poor sperm health, negatively impacting sperm motility, morphology, and count. Conversely, diets rich in healthy fats, like nuts, seeds, and omega-3 fatty acids, have been shown to improve sperm health.
Potential Shortcomings of the Keto Diet
Despite the potential benefits, there are several potential drawbacks to consider before adopting a keto diet for fertility:
Folate Deficiency
The keto diet can be restrictive of folate-rich foods. When people are eliminating carbs, they are eliminating fortified grains and large amounts of fruits and vegetables - groups of foods that are rich in nutrients like folic acid. Women who are trying to conceive are told that their intake of folic acid and folate are important to reduce the risk of babies developing neural tube defects. In fact, in the United States, many carb-heavy foods are made with flour that is fortified with folic acid. The keto diet restricts many of these fortified foods, and therefore women who are following a keto diet run the risk of not eating enough of this important nutrient.
Antioxidant Deficiency
The keto diet may be lower in antioxidants, which are found in many carbohydrate-rich foods like fruits. Antioxidants are thought to reduce the damage caused by oxidative stress, which has been implicated in some fertility challenges.
Stress on the Body
The keto diet can be restrictive and may cause added stress to the body, which is not conducive to fertility. If following the keto diet acts as a source of stress for a woman (either physiologically or mentally), it may be counter-productive.
Read also: Magnesium Supplements for Keto
Nutrient Deficiencies
The keto diet eliminates approximately 60% of foods we typically consume. Because the diet is so restrictive, it can be challenging to obtain all the necessary nutrients for optimal health and fertility.
Digestive Issues
Eating a high-fat diet can be taxing on one’s digestive tract, as fat can be hard to metabolize and break down.
Keto and Pregnancy: Safety Concerns
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, 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.
Much of the risk in pregnancy lies in ketoacidosis, which is a serious medical condition characterized by high blood glucose levels and high ketone levels. However, the keto diet has lead to ketoacidosis in some cases.
A handful of mouse studies have noted that exposure to ketones or following a ketogenic diet causes changes to embryo development. However, another found that exposure to a ketogenic diet increased sociability and reduced depression-like symptoms in the offspring of the ketogenic diet-fed mice. In a case report detailing two “keto pregnancies,” researchers found that one had no complications, but in the other the infant was born with some ear abnormalities.
Overall, it may be best for pregnant women to adopt a more flexible low carb approach throughout their pregnancies.
Alternatives to Keto
For those seeking a more balanced approach to preconception nutrition, experts often recommend the Mediterranean diet or a Dutch-style diet. These diets emphasize fruits, vegetables, lean proteins, whole grains, and healthy fats, providing a more balanced distribution of macronutrients and a wider range of essential nutrients.