There is so much information out there regarding the best dietary guidelines to follow if you have PCOS. Unfortunately, there is a lot of misinformation spreading faster than ever with advances in search engine and AI technology. Let’s look at what the research says and distill the information into a few concrete guidelines that have proven to be successful in both the research and in my own clinical practice.
PCOS is a broad diagnosis that includes different subtypes that benefit from unique treatment focuses. In this article, we will be focusing on PCOS patients who are overweight or obese with insulin resistance. However, most of these tips will still be helpful for anyone with PCOS, even if you are not overweight or obese with/without insulin resistance. The advice given here is helpful in promoting ovulation, a major goal of any PCOS patient, regardless of the subtype.
Have you been diagnosed with PCOS but you’re not sure if you have insulin resistance? With insulin resistance we see the following on labs: elevated fasting insulin, elevated fasting glucose, or elevated hemoglobin A1c.
In this article, we will cover:
- The main outcomes hoped for when incorporating dietary changes in patients with PCOS who are overweight/obese with insulin resistance
- Top nutritional recommendations to follow for PCOS
- Common dietary mistakes people with PCOS make
What are the main outcomes we seek when incorporating dietary changes in PCOS Patients?
Although dietary factors alone do not cause PCOS, nutrition is a valuable therapy for any PCOS patient, especially when there are the combined factors of being overweight/obese with insulin resistance. There are three main goals that I focus on with my patients to help them resolve their symptoms. These goals are as follows:
- Stimulate ovulation (everyone’s goal). The biggest goal for any PCOS patient is to stimulate ovulation. This will support regular cycles (26-32 days), enhance fertility, and eliminate many of your PCOS related symptoms. People with PCOS are likely to have anovulatory (no ovulation) cycles, which are caused by the underlying pathogenic factors involved in PCOS. Eating appropriately can feed your ovaries with high-quality nutrition which will promote quality egg development. High-quality egg development will promote ovulation, which is exactly what we want.
- Weight management. Weight can impact your symptoms and overall outcomes tremendously. Losing around 5% of body weight has been shown to improve ovulation and improve symptoms in PCOS Patients.1 Additional benefits of weight loss are improved mood, improved fertility outcomes, etc.
- Reverse insulin resistance. People with PCOS who have elevated insulin and testosterone are often caught in a vicious cycle involving these two hormones. High levels of insulin will stimulate the ovaries to make more testosterone which in turn will make more insulin. This cycle keeps feeding on itself, making symptoms worse. Dietary factors often play a huge role in insulin resistance. It is often the case that people with PCOS are not eating adequate fiber, enough healthy fats or enough protein for a healthy insulin response. 2
Knowing the overall goals of dietary recommendations helps to improve patients’ success in resolving symptoms. Many PCOS patients think that dietary changes are just for weight loss, but the benefits go way beyond that.
Top Nutritional Recommendations for PCOS
1. Reduce Caloric Intake
The common trend in dietary studies for the treatment of PCOS is that there is a caloric reduction in the study group, causing an improvement in the totality of symptoms. There are many types of diets that can be followed to achieve a lower caloric diet for patients with PCOS: low-carb diet, high-protein diet, ketogenic diet, low glycemic diet, Mediterranean, pulse diet, and Dash diet. Rather than counting calories, I find that the best approach here is to focus on your hunger ques, focus on eating until you are 80% full, eat at home as much as possible, eat a whole foods diet (noted below), and skip the caloric drinks (soft drinks, lattes, etc.). These will naturally reduce calories to a healthy level without creating a calorie deficit that may back fire for your metabolism in the long run.
2. Eat Whole Foods
Whole foods refers to foods that you can see growing or grazing in a field. Examples of these are vegetables, fruits, whole grains, legumes, nuts, seeds, and high-quality animal protein. A whole grain is one that is truly just a grain that has not been milled into a flour and then made into a bread, cereal, cracker, etc. Choose organic as much as possible as well as grass-fed or pasture raised without additives, antibiotics, or hormones. A 2019 study showed adherence to a Mediterranean diet decreased inflammatory markers, decreased testosterone levels, and improved Ferriman-Gallwey score (this score assesses the male-pattern hair growth some women with PCOS experience).4 A Mediterranean diet focuses on whole foods with an increase in healthy fats, olive oil in particular. Low consumption of fruits, vegetables, whole grains, meat, fish, olive oil, and nuts is common in PCOS patients. There is a clear link between poor dietary nutrition and worsening of PCOS symptoms. 2, 5 Increasing fiber, which happens naturally on a whole foods diet, will improve insulin resistance. Studies have shown that this is the case with PCOS patients.3 Remember that decreasing insulin resistance is one of our main goals.
3. Increase Protein Inake
Increasing protein intake has been shown to improve fasting insulin scores and HOMA-IR scores (a tool to evaluate insulin resistance).6 We know from older research that higher protein intake improves weight, menstrual cycle regularity, and insulin resistance.7 A good protein target to start with is 80g/day. Using an app like Cronometer can help you evaluate how much protein you are currently eating and then help you get a sense of what eating 80g/day looks like.
4. Increase Healthy Fats
Healthy fats include unsaturated fats (mono and polyunsaturated fats), like wild-caught cold water fish, olive oil, avocado oil, flax oil, nuts, seeds, and avocados. Choose extra-virgin, cold pressed oils. Avoid industrial seed oils, like soy, corn, canola and “vegetable oils.” Saturated fats in PCOS patients (obese or not) can increase inflammatory markers.8 This finding is largely from population based studies that suffer from “population bias.” We are not sure if it is the saturated fat that is the issue or if it is the other poor quality fats, like those used for deep frying and hydrogenated oils, that are often eaten in large amounts by the same people. We do find clinically that saturated fat in the form of organic butter, ghee and egg yolks in the context of a whole foods diet actually help improve fertility and menstrual cycles. Diets that are high in trans fats and saturated fats (fried/processed foods) can increase insulin resistance and worsen hormone imbalance.9 In the Mediterranean diet studies, we see an improvement in symptoms of PCOS with higher intakes of healthy fats.
Common Dietary Mistakes for People with PCOS
1. Not limiting processed foods
If you continue to eat processed foods, even if you increase protein and fiber, you will be unlikely to achieve the main dietary goals that support reversal of PCOS (stimulating ovulation, weight management, reversing insulin resistance). Processed foods are pro-inflammatory and if eaten on more than the rare occasion, they continually feed inflammation in the body. Inflammation does not support ovulation but will promote unwanted weight gain and insulin resistance. Processed foods are, for the most part, any food that comes in a box or package and has a list of ingredients. There are some exceptions such as whole grain rice but for the most part keep in mind that if it is packaged, it’s processed. There are definitely nuances to the degree of processing but the packaging and ingredient guidelines are the simplest way to explain it. Processed foods are an issue for multiple reasons. Processing strips the food of good nutrients and usually adds things to the food to make it more palatable (like added sugars, and artificial flavors) and/or have a longer shelf life. Packaged foods often substitute poor quality ingredients for more healthful ones, like using canola oil (inflammatory) instead of olive oil (anti-inflammatory) These all result in the packaged foods being inflammatory.
2. Eating too many whole grains
Whole grains are great, but keep them to a minimum. Too much can increase weight and feed insulin resistance. Grains can be easy to over eat, leaving less room for adequate protein, veggies and fruits. Focus on a wide variety of whole foods throughout the day.
My best advice to any PCOS patient is to take it one step at a time and build on top of each dietary habit to improve long-term outcomes. Dietary change does not need to be complicated. Plan and organize your meals for the week for improved success.
References:
- Goodman 2015 https://pubmed.ncbi.nlm.nih.gov/26642102/
- Huijgen, 2015 https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0142772
- Bernardes da Cunha 2019 https://pubmed.ncbi.nlm.nih.gov/30449604/
- Barrea 2019 https://pubmed.ncbi.nlm.nih.gov/31547562/
- Mattavelli 2023 https://pmc.ncbi.nlm.nih.gov/articles/PMC10145158/
- Wang 2024 https://pubmed.ncbi.nlm.nih.gov/38424054/
- Moran 2003 https://pubmed.ncbi.nlm.nih.gov/12574218/
- Gonzalez, 2021 https://pmc.ncbi.nlm.nih.gov/articles/PMC8782660/
- Han 2023 https://pmc.ncbi.nlm.nih.gov/articles/PMC10180647/#