A few years ago, the keto diet was all the rage—a high-fat, low-carb way to shed pounds quickly. While it’s lost a bit of its luster, as all diet trends do, interest in the keto diet remains. Specifically, those hoping to become parents wonder whether following this way of eating could support fertility. But is it true? Well, it’s certainly true that nutrition is a key consideration for health and fertility as a whole. So is a diet high in fat and low in carbs the answer? It’s possible. Here’s what to know about the keto diet and whether it might help support fertility.
- The keto diet is high in fats, moderate in protein and low in carbs, and designed to put the body in a state of ketosis that burns fat for fuel instead of sugar.
- There is some evidence that the keto diet can help reduce inflammation, which may be helpful for fertility.
- The keto diet, with its emphasis on healthy fats, may also support sperm health.
- While the keto diet can be helpful for losing weight, a more balanced approach to nutrition is better for conception and pregnancy.
What is the Keto Diet?
Short for ketogenic, the keto diet is high in fats, moderate in protein and low in carbohydrates. It’s a pretty restrictive approach to eating that prioritizes foods like animal proteins, dairy products like butter, non-starchy veggies and oils. Excluded are nutritious foods that are high in carbs, like fruits, starchy vegetables, legumes and grains, along with less-nutritions options that are high in sugar, such as baked goods.
The macronutrient ratio in the keto diet is designed to put the body in a metabolic state known as ketosis (1). When you significantly cut back on carbohydrates, which are the primary energy source for the body, it turns to body fat for energy instead. Improving the body’s efficiency at fat burning can mean a lot of rapid weight loss. But what does that mean for fertility?
Keto for Fertility in Women
One of the benefits of shifting from burning carbs for energy to body fat is a reduction in systemic, or body-wide, inflammation. That’s a good thing for fertility, since widespread inflammation can negatively affect the uterus, cervix and placenta (2). Following a keto diet properly may also help reduce insulin levels and could even regulate certain reproductive hormones, such as testosterone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH).
There’s also research that shows women with infertility who pursued IVF and ate an anti-inflammatory diet tend to have more successful pregnancy outcomes than those who didn’t follow this type of diet (3). Women with PCOS may also find the keto diet beneficial for fertility. Because it can help you lose weight, it may help ovulation resume and could even help rebalance hormones. A very small study published in 2018 followed four overweight women with PCOS who committed to ketogenic diets in the hopes of becoming pregnant (4). Within six months, all four women lost weight (between 19 and 36 pounds) and began regularly menstruating again, and two of them conceived without the need for ovulation induction.
Keto: Sperm Friendly?
Here at Beli, we’re keenly aware that two healthy partners are key for the healthiest possible conception, pregnancy and baby. For men hoping to become fathers, taking steps to reach a healthy weight by following a balanced diet is a standard recommendation. Unfortunately, the standard American diet, which is disproportionately filled with refined carbs and excess sugar, is pretty terrible for sperm health. In fact, it has a detrimental effect on all aspects of sperm health, from motility to morphology to count. Even an incredibly fertile woman is going to have a hard time if her partner’s sperm is subpar, so it’s important that couples take steps together to nourish and support their fertility.
The Best Strategy for Conception
If this is all sounding good, there’s a little more to the story. For many people, the keto diet is really hard to follow in a healthy way. It’s easy to turn to foods that are high in saturated fat, like bacon and butter, to remain in ketosis. Saturated fat can, of course, lead to higher cholesterol, which isn’t doing the heart any favors. What’s more, one of the biggest issues with going keto is the very real risk of nutrient deficiencies.
That’s a problem for fertility. In fact, couples who are hoping to conceive are advised to take prenatal vitamins (for her and for him!) specifically to shore up nutritional gaps in their diet. At Beli, we champion nutrient-dense diets that support your health as a whole, which is a direct reflection of your fertility health. By definition, the keto diet is restrictive, which really isn’t ideal for pregnancy. That level of nutrition restriction can also be stressful in general—another thing you don’t need when you’re hoping to conceive.
So what’s the answer? Does the keto diet support fertility? The smartest strategy is to follow the keto diet as a means of getting to a healthy weight before you try to conceive (because you definitely don’t want to be in ketosis during conception and definitely not during pregnancy). Then, you can switch to a diet that focuses on balanced nutrition instead of calorie restriction. The Mediterranean diet, which prioritizes fruits and veggies, lean meats, whole grains and healthy fats, has a more balanced approach to macronutrients, so it's less restrictive and may be easier to follow—with similar fertility-boosting benefits.
Evidence shows that carbs really aren’t the enemy, especially during the preconception stage (5). Specifically, the research found that when fewer than 45% of total calories in a daily diet come from carbs (which is technically defined as a low-carb diet), reproductive hormone levels can improve. Keto diets typically allow no more than 20% of calories to come from carbs, which is pretty darn low.
The Bottom Line
Nutrition is important when the goal is a baby, and both parents-to-be will benefit in numerous ways from getting a handle on what they eat. But the keto diet should be seen as a short-term strategy at best. While it can help you reach a healthy weight, you’re better off focusing on getting in a wide variety of nutrients through a balanced diet and supplementing with a high quality prenatal vitamin—and we have a great suggestion!
Higuera, V. (2022). Ketosis: Symptoms, benefits, risks and more. https://www.everydayhealth.com/diet-nutrition/ketogenic-diet/ketosis-what-it-its-safe-how-achieve-it-symptoms-more/
Vannuccini, S et al. (2016). Infertility and reproductive disorders: impact of hormonal and inflammatory mechanisms on pregnancy outcome. https://pubmed.ncbi.nlm.nih.gov/26395640/
Karayiannis, D et al. (2018). Adherence to the Mediterranean diet and IVF success rate among non-obese women attempting fertility. https://pubmed.ncbi.nlm.nih.gov/29390148/
Alwahab, U et al. (2018). A Ketogenic Diet may Restore Fertility in Women With Polycystic Ovary Syndrome: A Case Series. https://www.aaceclinicalcasereports.com/article/S2376-0605(20)30157-7/fulltext
McGrice, M et al. (2017). The Effect of Low Carbohydrate Diets on Fertility Hormones and Outcomes in Overweight and Obese Women: A Systematic Review. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5372867/