Is The Keto Diet BENEFiciaL for PCOS?


It’ s about time I shared my thoughts on the keto diet for PCOS. This is something that I get asked by my PCOS clients all. the. time. So I’m guessing that some of you might be interested in this topic as well!

The keto diet has gained a lot of popularity in recent years as a means for rapid weight loss.

There is SO much misinformation out there regarding diet and PCOS but the keto diet for managing PCOS might be least favorite of all.

Ahhh where to even begin! First let’s talk about what the keto diet actually is.

What is the keto diet?

The ketogenic diet or “keto” diet was developed in the 1920s as a therapeutic treatment for patient’s with epilepsy. A keto diet is very high in fat (about 75% of total calories), moderate in protein (about 20% of total calories) and low in carbohydrates (about 5% of total calories).

On a 2000 calorie diet, this would mean limiting carbohydrates to about 20-25 grams daily – less than 1 banana or 1 sweet potato.

By starving your brain of glucose (the body’s preferred source of energy coming from carbohydrates) your body is forced to burn fat for fuel in the form of ketones. A keto diet is NOT to be confused with a “low carb diet”.  

The keto diet also limits protein since protein can be converted to glucose through a process called gluconeogenesis.

Research has shown that a keto diet can improve epilepsy, lower blood sugar and insulin levels, improve insulin resistance and help with weight loss.

Burning fat for fuel? Lower blood sugar and insulin? Sounds great for PCOS! Not so fast…

The Keto diet Could Make PCOS symptoms worse

The glands that regulate the hormones in your body are very sensitive. When carbohydrate intake goes too low, this is a form of physiological stress on your body. As a result, your adrenal glands may start producing more cortisol (one of your body’s stress hormones).

Many women with PCOS already have overactive adrenals and higher levels of stress hormones in their body to begin with, so this can be a recipe for disaster.

Cortisol causes blood sugar levels to increase and can actually make insulin resistance worse over time.

Elevated levels of cortisol lead to more visceral fat (a fancy term for belly fat).

Research has shown that holding excess fat in your abdominal area increases a person’s risk for health conditions including type 2 diabetes and heart disease more than holding fat in other areas of the body.

Although initial weight loss may occur on a keto diet (as would cutting out any entire food group) the long-term impact of elevated cortisol levels from overly restricting carbohydrate intake may actually do more harm than good. 

The keto diet may negatively impact the gut microbiome

We know that the gut microbiome plays a major role in health and disease. Bacteria in the gut are crucial for the digestion and absorption of nutrients from food, immune function, the regulation of inflammation, the production of important vitamins, hormonal balance, insulin sensitivity and mental health. Shall I go on…?

There is a lot we still don’t know about the gut microbiome, but research has consistently shown that low bacterial diversity in the gut is harmful and a species-rich gut microbe community is beneficial.

One of THE most important ways to support the growth of beneficial bacteria in the gut is to consume a whole foods, fiber rich diet.  

What is the keto diet often deficient in? FIBER. Think vegetables, fruit, legumes, whole grains, etc.

Not to mention that fiber is crucial for promoting regular bowel movements. Going to the bathroom daily is essential for eliminating excess hormones.

The keto diet may be harmful for hormones

 Research has shown that overly restricting carbohydrates may result in irregular menstrual cycles or the complete loss of a period all together in some individuals.

Overly restricting carb intake may negatively impact thyroid hormones resulting in weight gain, mood disturbances, poor concentration and low energy levels. Sound fun?

The keto diet may increase your risk for being overweight in the future

The keto diet might produce rapid weight loss in the short-term, but it also might actually increase your risk for weight gain in the future.

Compliance and adherence to the keto diet in research studies is low, likely because of it’s restrictive nature. This means that it is probably not realistic for most people to follow in the long-term.

What is one of the biggest risk factors for weight gain? Chronic dieting (ahem...keto) & weight cycling.

When your body goes through periods of restriction a number of metabolic changes occur including greater fat storage, lean muscle loss and decreased energy expenditure. These are protective mechanisms that your body employs as a result of restriction.

The keto diet lacks important micronutrients

One of the major issues with PCOS is the underlying, low grade inflammation (evidenced by elevated inflammatory markers in women with PCOS). Women with PCOS are also at an increased risk for a number of micronutrient deficiencies.

If you’re following a ketogenic diet, you are likely missing out on crucial vitamins, minerals and antioxidants that have an anti-inflammatory and protective effect on your body (like colorful fruits and veggies!)

Higher fruit and vegetable intake is associated with lower levels of inflammatory markers and a decreased risk for developing chronic disease.

The keto diet can squash your social life

The keto diet can be incredibly stressful and socially isolating due to it’s restrictive nature. It takes a lot effort to count and micromanage every piece of food that goes into your body. Not to mention all of the fun foods you have to miss out on! I feel exhausted just thinking about it.

I’m going to go out on a limb here and say that most of us with busy lives don’t really want to live this way and be constantly stressing about food — we’ve got enough life stress as it is!

Final Thoughts

The keto diet may be necessary as a therapeutic intervention in SOME clinical cases when appropriate. This should be implemented with the guidance of your doctor and dietitian to ensure safety.

If you are pursing the keto diet to lose weight, improve energy, manage PCOS or balance hormones….you may actually end up worse off than when you started. I promise you — there is a better way!

I want to reiterate again that a keto diet is NOT just a low carb or controlled carb diet.

There are SO many ways to improve insulin resistance and manage PCOS that don’t involve the keto diet (read more here and here and here).

I work closely with clients to support them in determining their personal carb tolerance and a pattern of eating that is supportive of stable blood sugar and energy levels. Every individual is unique!

If you are serious about making dietary changes to improve your health and manage PCOS in the long-term…stop looking to generic diets and quick fixes.

Set up a free 30 minute discovery call if you’re interested in getting to the root of your symptoms and working with an integrative registered dietitian on a personalized nutrition and lifestyle plan for long-term health outcomes.

In the meantime you can check out some of my basic diet and lifestyle tips for PCOS here to get you started.

In health,

Jillian Greaves, MPH, RD, LDN

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5 Nutrition and Lifestyle Tips for Managing PCOS Naturally


Polycystic ovarian syndrome (PCOS) affects 1 in 10 women. Despite how common PCOS is, I’ve found that there is a major lack of support from a diet and lifestyle standpoint for women with PCOS. Fortunately there are many ways to manage PCOS naturally. Diet and lifestyle interventions for PCOS are incredibly personalized and multi-faceted, so keep in mind that these recommendations are not personalized to address your specific needs.

Stabilize Blood Sugar and Improve Insulin Resistance

Insulin resistance and excess amounts of insulin are common in women with PCOS. This combination contributes to metabolic problems and affects the hormones that control your menstrual cycle. High levels of insulin can stimulate the ovaries to produce more testosterone. This can lead to acne, hirsutism, anovulation and infertility.

Insulin is a hormone produced by the pancreas and it’s primary job is to bring glucose out of the blood stream and into your cells to be used for energy. Your cells need glucose to function optimally, but the mechanism that allows insulin to usher glucose into your cells does not always work properly in PCOS.

Because your cells are already having a difficult time accessing energy, cutting out carbs or overly restricting carbohydrates is not the answer. This can make thing worse and lead to further disruptions to endocrine function, hypoglycemia, fatigue and intense cravings. Overly restricting carbohydrates also typically leads overeating them later on.

We also don’t want to chronically overeat carbohydrate foods leading to big spikes in blood sugar and higher levels of circulating insulin.

So how do you stabilize blood sugar and improve insulin resistance?! Focus on eating consistently throughout the day (about every 4 hours or so) and including moderate amounts of carbohydrates at meals and snacks. Choose fiber rich carbs which are broken down and digested more slowly to prevent rapid spikes in blood sugar (starchy vegetables, beans, quinoa, oats, fruit). Pair starchy foods with protein, fat and non-starchy vegetables for optimal blood sugar stability.

The amount of carbohydrates you need daily is very individualized, but a good starting place is to think about ¼ plate high fiber carb, ¼ plate protein, ½ plate non-starchy vegetables and 1-2 servings fat at meals. This is NOT about perfection! This is also not about beating yourself up over the pizza and beer you enjoyed with friends last weekend. There is a lot of flexibility here. It’s about mindfulness and fueling your body appropriately on a consistent basis.

Reduce Inflammation

Inflammation is a trendy topic right now that you can read more about here. PCOS is associated with chronic, low grade inflammation that isn’t fully understood (evidenced by elevated inflammatory markers in women with PCOS). Chronic inflammation can increase the risk for a number of chronic diseases, therefore one of the goals in managing PCOS is to reduce chronic inflammation.

So how do you support your body in reducing inflammation? Include more omega 3 fatty acids which are super important for reducing inflammation. Some of my favorites include fatty fish, hemp seeds, chia seeds, tahini, walnuts and olive oil.

Eat more plants! Higher fruit and vegetable intake is associated with lower levels of inflammatory markers and a decreased risk for developing chronic disease. Vegetables and fruit are rich in vitamins, minerals and antioxidants that have an ant-inflammatory and protective effect on our bodies. Aim for 7-9 servings daily and choose a variety of colors!

Use herbs and spices liberally. Not only are herbs a great way to flavor your food, but they’re also really amazing chemical compounds that have the ability to disrupt inflammatory pathways and even inhibit the release of inflammatory messengers. Use more turmeric, cinnamon, ginger, black pepper, oregano, thyme and rosemary to flavor food.

Prioritize and Protect Time for Daily Stress Management

Chronic stress disrupts your body’s stress response systems and results in increased cortisol secretion (one of your body’s stress hormones). Chronically elevated levels of cortisol impacts insulin, progesterone, testosterone, DHEA and thyroid hormone production. Stress can impact your body’s ability to regulate inflammation, impair digestion, promote weight gain, and result in the loss of a normal period. Is this stressing you out?! Unfortunately stress isn’t going anywhere, so it’s important to prioritize stress management activities daily to support healthy hormonal balance.

Stress management is also very personalized. The most important thing is to find something that works for YOU and to make it a part of your daily life. Some ideas include guided mediation, yoga, seeing a therapist, going for a walk and getting fresh air and deep belly breathing.

Talk about supplements with your Dietitian or Doctor.

There are several supplements that can be very helpful with PCOS. Women with PCOS are commonly deficient in a number of vitamins and minerals which might be due to increased needs, poor absorption or increased secretion. Common deficiencies include zinc, copper, magnesium and vitamin D. I always prioritize these crucial vitamins and minerals via food and supplementation as necessary.

In addition to correcting any deficiencies, there are other supplements that can be used to help with balancing sex hormones, promoting insulin sensitivity and reducing inflammation. Below are some common supplements I use in my practice with clients. Keep in mind that supplements are very individualized. Please consult your Dietitian or Doctor before starting anything new.

Inositols are pseudovitamins found in many foods. Myo and d-chiro inositols are the most well researched in PCOS. Myo + d-chiro inositol supplementation in a 40:1 ratio has been shown to help with insulin resistance, dyslipidemia, hypertension, weight loss and egg quality. Learn more here and here.

NAC is a derivative of L-cysteine which is a precursor to glutathione. NAC acts as an antioxidant and an amino acid that can help reduce oxidative stress, improve insulin resistance, improve egg quality and ovulation and lower androgens. Learn more here.

Berberine is an ancient herb that acts as an insulin sensitizer that may also help with reducing LDL cholesterol, triglycerides and testosterone levels. Learn more here.

Omega 3s are essential fatty acids. This means that the body does not produce them, and we have to obtain them from food. In addition to including more omega 3 rich foods (see above), an omega 3 supplement may be beneficial for decreasing inflammation, improving insulin resistance, lowering androgens and improving depression (women with PCOS experience higher rates of depression and anxiety). Learn more here.

Reduce Exposure to Endocrine Disrupting Chemicals

Endocrine disrupting chemicals can impact hormone levels that may contribute to inflammation, infertility and metabolic alterations seen in PCOS such as weight gain and insulin resistance.

It’s impossible to completely eliminate exposure to ALL endocrine disrupting chemicals in the world that we live in. However it is possible to consciously reduce your exposure to endocrine disrupting chemicals with small but impactful changes:

Minimize your use of plastics in the form of single use plastic bottles and tupperware. Purchase a glass or stainless steel water bottle and glass tupperware.

Look for personal care products free of parabens, formaldehyde, phthalates, petroleum jelly, PEG, food dye and coloring and synthetic fragrances. I love Follain, Credo Beauty and Beauty Counter for personal care products.

Switch out household cleaning products with non-toxic alternatives. I’m a fan of Seventh Generation and Branch Basics.

*Remember that these are general tips and not a substitute for individual medical or nutrition advice. Always consult with your health care provider before making changes or starting supplements.

If you’re ready to work together on a personalized diet and lifestyle plan with the support of an Integrative Registered Dietitian, set up a free introductory phone call to learn more about the program.

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