If you’ve been wondering whether the keto diet could help manage PCOS, you’re in the right place.
In this article, we’ll dive into what the science actually says about keto and PCOS – without the hype.
Polycystic Ovary Syndrome (PCOS) is a complex metabolic and hormonal condition. If you’re living with PCOS, chances are you’ve already tried a few different strategies to feel your best. (And if you’re anything like many of my clients, you’re tired of the conflicting advice out there!)
While I’ve shared lots of tips for managing PCOS in other posts, today we’re zooming in on one hot topic: the keto diet for PCOS.
As a Halifax-based dietitian specializing in women’s health, I’m here to break it all down for you.
By the end of this blog post, you’ll have a clear understanding of what the keto diet actually is, why it’s become such a popular topic in the PCOS community, whether it’s truly helpful for managing PCOS symptoms, and if it might even play a role in improving fertility.
Ready to jump in?
Let’s take a science-backed look at keto and PCOS – and find out what’s really worth your time.
What Is PCOS?
Polycystic Ovary Syndrome (PCOS) is a complex hormonal condition that affects about 5–10% of women of reproductive age.
It’s often marked by a mix of symptoms like irregular periods, weight gain, acne, excess hair growth (especially on the face and body), thinning hair on the scalp, and even infertility.
PCOS is actually the leading cause of infertility in women – and it can increase the risk of other health concerns too, like type 2 diabetes, gestational diabetes, heart disease, and high blood pressure.
Since there’s no cure for PCOS (yet!), the focus is on managing symptoms through a combination of diet, physical activity, medications, and supplements.
Over the years, researchers have explored many different eating patterns to help support PCOS management – including the keto diet, which we’ll be talking more about today.
Most people with PCOS benefit from working with a team that includes a medical doctor (like an endocrinologist) and a dietitian.
What Is the Keto Diet?
The ketogenic (“keto”) diet is a low-carbohydrate, high-fat, moderate-protein eating style that shifts your body’s metabolism into a state called ketosis.
In ketosis, the body becomes highly efficient at burning fat for energy instead of relying on carbohydrates.
Originally developed back in the 1920s to help manage epilepsy, the keto diet has since gained popularity for its potential benefits in weight loss, blood sugar control, and metabolic health (including conditions PCOS).
By dramatically reduing your carb intake, the keto diet dramatically changes how your body processes nutrients. It’s often promoted as a way to influence hormones, boost insulin sensitivity, and calm inflammation – three big buzzwords in the PCOS world.
That said, just because a diet gets a lot of buzz doesn’t mean it’s the right fit for everyone.
Understanding how keto works (and what it actually does inside the body) is key to making an informed decision about whether it’s right for you.
Keto Basics: Low-Carb, High-Fat Explained
The foundation of the keto diet is its macronutrient composition:
- 70–80% of calories from fat
- 10–20% from protein
- Just 5–10% from carbohydrates
This usually looks like:
- Fats: avocado, olive oil, butter, nuts, seeds, fatty fish
- Proteins: eggs, poultry, beef, pork, tofu
- Low-carb veggies: spinach, kale, zucchini, cauliflower, broccoli
Meanwhile, high-carb foods like bread, pasta, rice, beans, most fruits, and anything sugary get heavily restricted (often limited to just 20–50 grams of carbs per day).
The goal? To lower your body’s glucose supply so it’s forced to burn fat for fuel, producing molecules called ketones to keep you energized.
Proponents of keto often highlight its potential to stabilize blood sugar levels, lower insulin spikes, and improve appetite control.
For those with PCOS (where insulin resistance is common), these effects can sound promising – but it’s important to remember that keto isn’t the only way to reach these goals, and it’s not a cure-all.
What Happens to Your Body on Keto?
When you significantly restrict carbohydrates, your body undergoes several major metabolic changes, some of which can be quite intense and potentially harmful if not done carefully:
Depletion of glycogen stores (and water loss)
Glycogen (your carb storage in your muscles and liver) holds onto water. As you burn through glycogen, you also lose water weight – often leading to a quick drop on the scale during your first few days.
Important reminder: early weight loss is mostly fluid, not fat.
Ketone production
As glucose runs low, your liver starts turning fat into ketones, an alternate energy source for your brain and body. This metabolic shift typically kicks in within a few days.
While mild ketosis can be safe for many people, sustained high levels of ketones can sometimes strain the kidneys and upset the body’s acid-base balance – especially if you’re not careful.
Drop in insulin levels
Eating fewer carbs naturally leads to lower insulin levels. For people with PCOS and insulin resistance, this can seem like a win.
However, abrupt changes in blood sugar and insulin levels can also cause dizziness, fatigue, headaches, irritability, and difficulty concentrating – especially during the first couple of weeks.
Keto flu
As the body transitions away from carbohydrates, many people experience a group of symptoms known as the “keto flu”.
The symptoms include fatigue, brain fog, muscle cramps, and mood changes. These symptoms reflect the stress that a drastic dietary change places on the body and can last several days to weeks.
In short:
While the ketogenic diet can trigger some metabolic changes that sound appealing, it also puts significant stress on the body – and it isn’t a magic solution for PCOS.
My goal isn’t to recommend or discourage keto, but to give you the full picture so you can make the best choice for your long-term health.
Diets need to be sustainable, nourishing, and supportive of your whole health – not just a short-term fix.
Is a Keto Diet Good for PCOS?
The keto diet has been explored as a possible strategy for managing some PCOS symptoms, particularly because of its effects on insulin resistance, weight management, and hormone regulation.
Some small studies and clinical reports suggest that a very low-carb, high-fat diet may improve certain metabolic markers in people with PCOS.
However, research is still quite limited – and keto is not universally recommended as a first-line approach when managing PCOS symptoms.
While some people may experience benefits, the keto diet also carries risks, including nutrient deficiencies, gastrointestinal issues, and difficulty sticking with the diet long-term.
That’s why anyone considering keto for PCOS should work closely with a healthcare provider, like a dietitian, to make sure it’s done safely and with a sustainable plan in mind.
Keto and Insulin Resistance
There’s growing evidence that a keto diet may help improve insulin resistance – a major driver of PCOS symptoms.
Several studies have found that following a keto diet can lower insulin levels and improve the body’s sensitivity to insulin, which is key for managing PCOS.
For example:
- A review of multiple studies found that the keto diet decreased insulin levels and improved HOMA-IR (a measure of insulin resistance) in women with PCOS.
- A low-calorie version of the keto diet helped teenagers with PCOS manage their weight, blood sugar, and cholesterol levels.
- Similar benefits were observed in women with obesity and PCOS who followed a ketogenic eating plan.
- One study even found improvements in insulin metabolism after just 12 weeks on a Mediterranean-style keto diet.
Bottom line: While early findings are promising, most of these studies were short-term. We still need more long-term research before making strong recommendations about keto for insulin resistance in PCOS.
Keto and Hormone Levels
Research also suggests that keto may impact hormone levels involved in PCOS.
For instance, a review by Turetta et al. found that the keto diet:
- Reduced luteinizing hormone (LH) levels
- Lowered the LH/FSH ratio (often elevated in PCOS)
- Decreased total and free testosterone
- Increased sex hormone-binding globulin (SHBG)—a protein that helps regulate hormone activity
Another study (the Mediterranean-style keto one mentioned above) found that after 12 weeks, participants had:
- Lower testosterone and DHEAS levels
- Higher estradiol, progesterone, and SHBG levels
These hormonal changes point toward a shift in the right direction for people managing PCOS. However – as always with nutrition research – it’s important to remember that what works for some may not work (or be sustainable) for everyone.
Can Keto Help with Weight Loss in PCOS?
A 2022 meta-analysis found that low-carb diets – including the ketogenic diet – can lead to significant short-term weight loss, especially within the first 3 to 8 months.
However, by 10 to 30 months, the differences in weight loss between keto and other diets were no longer significant. This suggests that while keto may be effective early on, its long-term sustainability and results are less certain.
Another review concluded that the keto diet is supported by moderate-quality evidence for reducing body weight and improving some markers of metabolic and heart health. Still, the authors emphasized the need for more long-term studies before drawing firm conclusions.
Bottom line: The keto diet may support short to medium-term weight loss in people with PCOS, but it’s not a guaranteed long-term solution – and it’s not the only option.
For weight management to be truly effective, it needs to be sustainable and support your overall health and well-being.
Can Keto Help with Fertility in PCOS?
There’s growing interest in how the keto diet might influence fertility outcomes in people with PCOS – and some early research looks promising. But it also comes with some important caveats.
One 2023 study followed 27 women with PCOS. Half started with a keto diet for 8 weeks, followed by a low-calorie diet for 8 more weeks. The other half followed a low-calorie Mediterranean-style diet the entire time.
Women who began with keto saw a significant jump in ovulation rates – from around 39% at baseline to nearly 85% after 16 weeks. Those on the Mediterranean-style diet had a smaller, non-significant improvement.
Other small studies have shown that keto may improve menstrual regularity, ovulation, and even increase chances of pregnancy and live birth in women with PCOS.
In one study, 8 out of 12 women with PCOS who had previously experienced unsuccessful IVF cycles became pregnant after following a keto diet for about 14 weeks – 7 of them went on to have live births.
Researchers believe these improvements are likely linked to the diet’s effects on weight loss, improved insulin sensitivity, and lower testosterone levels.
But – and this is a big but – keto is not without risks, especially when it comes to fertility and pregnancy.
The diet can lead to nutrient deficiencies if not carefully planned, particularly in fiber, vitamins, and minerals. And animal studies have raised concerns about potential risks to fetal brain development and fertility when a ketogenic diet is followed during pregnancy.
For this reason, most experts do not recommend continuing a strict keto diet during pregnancy.
If you’re trying to conceive and considering a ketogenic approach, it’s important to work closely with a registered dietitian or other qualified healthcare provider to weigh the risks and benefits – and to make sure your body is supported in the process.
Possible Risks of a Keto Diet for PCOS
Nutrient Deficiencies
By cutting out many fruits, whole grains, legumes, and some vegetables, the keto diet can make it difficult to meet daily needs for key nutrients like fiber, potassium, magnesium, calcium, iron, and phosphorus.
Over time, these nutrient gaps can contribute to serious health issues, including constipation, bone loss, heart rhythm abnormalities, and poor gut health.
Gastrointestinal (GI) Symptoms
Many people experience digestive issues when starting keto, including constipation, diarrhea, bloating, and nausea.
These symptoms often stem from a sharp drop in fiber intake and shifts in the gut microbiome. Changes in gut bacteria can have broader effects – not just on digestion, but also on immune function, inflammation, and metabolic health over the long term.
Risk of Disordered Eating
The highly restrictive nature of the keto diet – with its strict focus on carbohydrate elimination and fat loading – can foster an unhealthy preoccupation with food, body weight, and macronutrient counting.
Research shows that rigid dietary rules can increase the risk of developing disordered eating patterns, especially for those who are already vulnerable.
Obsessive behaviors around food tracking and fear of eating outside set macronutrient ratios are red flags for unhealthy relationships with food.
As a dietitian, I take this risk very, very seriously. In my professional opinion, the potential harm of triggering or worsening an eating disorder far outweighs any short-term benefits that might come from following a strict ketogenic diet.
When it comes to PCOS management – or any health goal – your mental and emotional well-being are just as important as your physical health.
Balanced, lower-carb day of eating for PCOS that emphasizes protein, fibre, and complex carbs – without going full keto.
This style of eating supports blood sugar balance, hormone health, and long-term sustainability:
Breakfast
Savoury Veggie Omelet + Berries & Chia
- 2 eggs + 2 egg whites scrambled with sautéed spinach, mushrooms, and tomatoes
- 1 oz feta or avocado on top
- Side of ½ cup berries
- 1 slice of multi grain toast
Why it works: High in protein, fiber, and antioxidants. The small portion of berries and 1 slice of multi grain bread provides natural carbs with minimal blood sugar spike.
Lunch
Grilled Chicken Power Bowl
- 4–5 oz grilled chicken breast
- ½ cup cooked quinoa or lentils
- Mixed greens, cucumbers, shredded carrots, cherry tomatoes
- 1–2 tbsp olive oil + lemon vinaigrette
- Optional: sprinkle of hemp seeds or pumpkin seeds
Why it works: Balanced plate with lean protein, slow-digesting carbs, fiber-rich veggies, and healthy fats for hormone support.
Afternoon Snack
Hummus Plate with Veggies & Seeds
- ¼ cup hummus, sprinkle of sunflower or pumpkin seeds on top for added protein and crunch
- Sliced cucumber, red bell pepper, and celery sticks
- 2 hard-boiled eggs
Why it works: A great blood sugar–balancing combo of protein, healthy fats, and fiber.
Dinner
Salmon with Roasted Veggies & Sweet Potato
- 4–6 oz baked salmon (seasoned with herbs, lemon, garlic)
- Roasted broccoli, zucchini, and bell peppers
- ½ medium roasted sweet potato
Why it works: Anti-inflammatory omega-3s, complex carbs for energy, and fiber to support digestion.
Optional Evening Snack (if hungry)
Dark Chocolate & Walnuts
- 1 square (70–85%) dark chocolate
- Small handful (5–6) walnuts
Why it works: Satisfies cravings in a blood sugar–friendly way with healthy fats and magnesium.
Curious about the best diet for managing PCOS? Don’t miss my evidence-based guide from a registered dietitian: A Dietitian’s Guide to the Best PCOS Diet.
Final Thoughts: Is Keto Good for PCOS?
While the keto diet has shown some short-term benefits for certain people with PCOS – particularly around insulin resistance, weight loss, and fertility – it’s important to zoom out and look at the bigger picture.
Like many restrictive diets, keto can be hard to sustain. Once the diet ends (as it often does), any progress can be difficult to maintain. Plus, most of the research supporting keto for PCOS is short-term.
We still don’t know the long-term effects of staying in ketosis, and there are real concerns – especially around nutrient deficiencies, gut health, and pregnancy safety.
In my expert opinion, a healthier and far more sustainable approach is to focus on a balanced diet that includes high-fiber foods, colorful fruits and vegetables, lean proteins, and complex carbohydrates.
These foods support hormone health, blood sugar balance, and overall well-being – without the extreme restrictions of keto.
At the end of the day, managing PCOS is about building habits you can stick with for life – not chasing quick fixes.
FAQ
Is the Carnivore Diet Good for PCOS?
The carnivore diet – which eliminates all plant foods and focuses solely on animal products – is not recommended for PCOS.
While it may lead to short-term weight loss, it completely removes fiber, fruits, vegetables, and other plant-based nutrients that are essential for hormone balance, gut health, and insulin sensitivity.
Over time, this extreme approach could do more harm than good – especially for your heart, digestive system, and long-term health.
Is the Paleo Diet Good for PCOS?
The paleo diet emphasizes whole foods like lean meats, fish, fruits, vegetables, nuts, and seeds, while excluding grains, dairy, and processed foods.
This approach can be a helpful starting point for some people with PCOS – especially those looking to reduce processed food intake.
However, it can become overly restrictive if not personalized. Including a broader range of foods – like whole grains and dairy for those who tolerate them – may be more sustainable and supportive of long-term health and hormonal balance.
Fad Diets No More! Need Support with PCOS Nutrition?
Want a clear plan for PCOS-friendly eating that doesn’t involve crash dieting? Grab my ebook, The PCOS Plate, and get started today.
It’s packed with everything you need to start feeling more energized, balanced, and in control of your health. Think of it as your go-to guide for managing PCOS symptoms through food – with sustainability at its core.
You deserve to feel vibrant, supported, and empowered on your PCOS journey – and I’m here to help every step of the way.
Madison is a Registered Dietitian and Certified Diabetes Educator passionate about helping women with PCOS navigate nutrition with confidence. Through science-backed nutrition and lifestyle strategies, she shares practical, sustainable approaches to support hormone health, blood sugar balance, and a healthier relationship with food — one meal at a time.