This post was updated on July 24th, 2022
By Kym Campbell, BSc. | Updated July 24th, 2022
Polycystic ovary syndrome (PCOS) describes a collection of symptoms that may, on their surface, not seem all that related. What we now know though, is that poor insulin regulation, and chronic inflammation are the primary mechanisms that connect all PCOS symptoms. The hormone imbalance they cause can result in weight gain, irregular periods, hair loss, acne, high blood pressure, mood swings, and more.
The good news is that both of these mechanisms are affected by diet. This means we can do something about it. For example, many women start to see positive results within the 4-week duration of my free 30-Day PCOS Diet Challenge. Reports of weight loss, improved sleep, more energy, and less acne are particularly common.
While eating the right foods is half of the battle, understanding what not to eat with PCOS is just as important. This article describes the most important foods and ingredients to avoid as well as what to eat instead.
You can also download a full list of common foods to avoid here.
When it comes to sugar and PCOS, we want to keep them separate as much as possible. This is because sugar disrupts insulin regulation and causes inflammation [1, 2].
Sugar/sucrose consists of 50% fructose and 50% glucose.
Fructose is scarcely found in paleolithic diets, so we’re not well suited to consume large amounts of it. The excessive fructose intake of typical western diets causes deterioration of the intestinal barrier and endotoxemia . This is where toxins in our gut leak into the bloodstream and cause an inflammatory response.
Fructose is processed by the liver. This is why high consumption has been linked to liver disease and insulin resistance [4, 5]. As I explain in my free 30-Day PCOS Diet Challenge, fructose-rich foods should be at the top of any foods to avoid list. This includes things like candy, sugary beverages, breakfast cereals, condiments, and sauces.
But, while fructose is bad for PCOS, readily available glucose isn’t all that great either. As explained further below, the other half of a sugar molecule has problems of its own.
Carbohydrate foods can be classified as being either “simple” or “complex”. Simple carbohydrates include readily available sugars like sucrose, fructose, and glucose. Complex carbohydrates, by comparison, are the main building block of starchy foods.
Carbohydrate foods get digested into glucose. They then enter the blood to provide the energy needed for healthy metabolism. The glycemic index (GI) of a food, describes the rate at which it causes blood glucose levels to rise. The higher the GI, the higher our responding insulin levels are going to be. Humans are well-adapted to consuming high-fiber, low-GI carbohydrate foods like root vegetables. But, the regular consumption of high-GI, glucose-rich foods can cause insulin resistance and make PCOS worse [6, 7]. This includes foods like French fries, white rice, pasta, and anything high in sugar. Baked goods and foods made from white flour are also important to avoid.
For a list of common high-GI foods download my free Foods to Avoid Checklist here.
The idea of following a gluten-free diet for PCOS has gained a lot of ground in our community, and for good reason too.
Gluten is a general name for the various proteins found in wheat, rye, and barley. Gluten is understood to be the trigger for celiac disease. Of more relevance to women with PCOS though, is a different kind of gluten intolerance, known as non-celiac gluten sensitivity.
There’s currently no evidence-based research connecting PCOS to non-celiac gluten sensitivity. But, the collective experience of women from my free 30-Day PCOS Diet Challenge suggests an important link. The most successful participants, almost without exception, find that going gluten-free is an essential step.
This makes sense when you consider the impact of gluten on the gut. Several studies have shown that gluten can cause “leaky gut syndrome” in predisposed people . Lab studies suggest that gluten increases intestinal permeability in all individuals – even if they’re otherwise healthy .
As with excessive fructose consumption, the deterioration of the intestinal wall-lining causes inflammation. This occurs when toxins move from our gut, where they do little harm, to our blood, where they’re not supposed to be. For women with PCOS, eating gluten adds fuel to the fire of inflammation. This then impacts our metabolic health, body weight, skin, hair, mood, and fertility.
Common gluten-containing foods include pasta, bread, breakfast cereals, and other processed foods.
Like gluten, there’s a lack of scientific evidence linking the consumption of dairy to PCOS. Reasonable arguments can be made on both sides of this debate. For example, there’s evidence that dairy contributes to acne development . But other studies suggest that dairy doesn’t impact ovulation or fertility .
The problem with most dairy-related studies is that they’re not designed for women with PCOS. As stated in a recent review of the evidence, “…studies concerning the influence of milk consumption in women with PCOS are scarce, so its beneficial effect may not be explicitly confirmed in this group of patients.” .
This is a situation where clinical experience is required.
From what I’ve observed as a health coach, it seems that some women with PCOS can tolerate dairy better than others. My view though, is that without having completed an elimination diet first, the hazards of dairy outweigh the benefits.
During my Beat PCOS 10-Week Program, all participants go gluten and dairy-free. This helps people better understand how they respond to these foods. It’s common for participants to discover that these foods no longer agree with them, even if beforehand, they thought otherwise. These women were living with an undiagnosed dairy sensitivity. Like non-celiac gluten sensitivity, this food intolerance can damage the intestinal wall lining. When this happens, the body defends itself with an inflammatory response, making PCOS symptoms worse.
It’s not only lactose that causes these sorts of problems. The proteins casein and whey can interact with the immune system too. These proteins are present in most dairy products including cream, yogurt, and cheese. Butter and ghee are the only dairy ingredients suitable for a PCOS diet. These contain only trace amounts of casein, whey, and lactose, as they’re mostly a pure source of milk fat.
5. Vegetable Oils
Vegetable oil is a euphemism for industrial seed oils. These processed oils come from soybeans, corn, rapeseed (canola), cottonseed, and safflower seeds. Most fried foods and processed foods will use one of these oils. Women with PCOS want to avoid these ingredients because they lead to increased inflammation.
Industrial seed oils can cause inflammation as a result of their imbalance of omega fats. Omega-6 fats produce pro-inflammatory metabolites, while omega-3 fats give rise to anti-inflammatory derivatives. A ratio of between 4:1 to 1:1 omega 6:omega 3 is considered ideal. Yet, the average Western diet results in a ratio of 20:1 or higher . Industrial seed oil consumption is often the primary cause of this imbalance. This is because they’re high in omega-6 fats and low in omega-3s.
This is of critical importance to women with PCOS as an omega fat imbalance has been linked to several related health risks. This includes depression , cancer , cardiovascular disease, arthritis, and kidney disease .
6. Processed Foods
The problem with processed foods is that they’re often high in sugar and carbs. This disrupts healthy blood sugar regulation. They also tend to contain vegetable oils, dairy, gluten, and food additives. These ingredients can cause inflammation.
While fast food is the quintessential example, processed foods can be any agricultural product that’s been mechanically, thermally, or chemically treated. But it’s important to understand that it’s mostly about the ingredients, rather than the definition.
Salted pork rinds, for example, could be considered “processed”. But certain brands only contain pork skins, and sea salt, making them an excellent snack. Pringles, by comparison, contain more than 20 ingredients. And most of these are either carbs, vegetable oil, sugar, or additives.
Yum, but also yuck.
Processed meats should also be assessed based on their ingredients. Additive-free sausages are usually fine, but it’s best to avoid foods like ultra-processed hot dogs.
The key take-home here is that if it comes with a nutrition label, then it’s worth reading it. If you don’t like the looks of the ingredients (or you don’t know what they are), then it’s a food that’s best avoided.
From a nutritional perspective, alcohol is one of the most obvious foods to stay away from. Alcohol is unnecessary, and even rare consumption has been associated with increased rates of liver disease in women with PCOS .
Studies have shown that this hazard affects PCOS women across the spectrum .
I’m not suggesting that women with PCOS should never drink alcohol, but the risks of doing so are often underappreciated.
The Bottom Line
PCOS is a disorder driven by poor insulin regulation and chronic inflammation. Both of these mechanisms are dialed up or down by the foods we eat. Because of this, dietary change is a powerful, evidence-based intervention for reducing the full scope of PCOS-related symptoms.
With the right lifestyle changes, women suffering from PCOS can take back control of their health and fertility. As well as leaning on healthcare providers and fertility specialists, there’s a lot we can do to help ourselves.
The seven most important foods to avoid with PCOS include sugar, carbs, gluten, dairy, vegetable oils, processed foods, and alcohol. Reducing or cutting these foods entirely is a valuable part of a long-term healthy eating plan. If you can do so, then you can expect to see significant improvements in your symptoms.
What To Eat Instead
With all this knowledge of what not to eat with PCOS, the obvious next question is, “what should I eat instead?” The short answer is to follow these core principles:
- Eat slow-carb and low carb, from whole food sources. A low carb, low GI diet helps stabilize blood sugar levels. This improves insulin sensitivity and restores hormone balance.
- Consume healthy fats. This improves satiety generally. Certain fatty acids, especially those found in beef, lamb, and coconut oil, can also improve insulin sensitivity [18, 19] and reduce body fat [20-23].
- Get enough protein. Adequate protein is essential for good health. An “adequate” amount though, varies with sex, age, body mass index, activity levels, and more. The USDA provides a useful online calculator for estimating an appropriate protein intake. Fatty fish and both high-fat and lean meats are the best sources of protein.
- Eat high-fiber foods. Doing so supports gut health, and reduces inflammation.
- Eat non-starchy vegetables. Non-starchy vegetables are rich in fiber which is good for gut health. They’re also an excellent source of vitamins, minerals, and other micronutrients.
Ready To Take Action?
Foods To Avoid FAQ
What about red meat? Red meat is good for PCOS and grass-fed meat is better than grain fed. It has a high nutritive value and superior fatty acid profile. Studies show that increased red meat intake does not elevate markers of inflammation [24, 25].
Is soy okay for PCOS? There’s conflicting information in the scientific literature when it comes to soy and PCOS. For example, studies have found that soy consumption can increase the risk of developing hyperthyroidism . But others have found that high soy consumption doesn’t alter thyroid function . Soy intake is associated with reduced rates of obesity, cardiovascular disease, insulin resistance, and immune disorders . The clinical significance of these findings for women with PCOS though, remains unclear.
Is corn good for PCOS? Whole foods and minimally processed sources of sweet corn have a relatively low glycemic index. When consumed in moderation, corn can be a helpful addition to any PCOS-friendly diet.
Is mayonnaise good for PCOS? Mayonnaise is predominantly oil, so the type of oil used determines if a product is good or not. Avocado or olive oil-containing products are best. Those that use vegetable oils such as soybean oil, or canola are best avoided.
Which fruits to avoid in PCOS? A PCOS diet can accommodate 1-2 servings per day of fresh whole fruit. Low-sugar fruits are best. This includes things like cantaloupe, currants, and berries. Sweeter fruits such as grapes, mango, banana, and apple, are best minimized.
Which vegetables to avoid for PCOS? Vegetables, especially non-starchy vegetables, should be a core component of any meal. Starchy vegetables such as potato, sweet potato, yam, and corn should be eaten in moderation to limit carbohydrate intake. Women who experience GI discomfort should also be mindful of vegetables that are rich in fermentable fibers. Examples include things like asparagus, onions, and cabbage. These “high FODMAP” vegetables may cause bloating in sensitive individuals.
What about white rice for PCOS? There’s a large variation in the glycemic index of different types of rice. Generally speaking, though, white rice (excluding Basmati) tends to have a higher GI than brown, red, black, or wild rice. Regardless of the rice consumed, it’s recommended that women with PCOS limit rice serving sizes. ½ cup per serving or less is best to prevent any adverse impacts on blood sugar levels.
What are the most important dairy products to avoid for PCOS? As well as lactose, the dairy proteins, casein, and whey are both problematic for women with PCOS. High moisture dairy products like milk, yogurt, ice cream, and soft cheeses are the most important foods to avoid. Very hard cheeses may cause less of an issue. Ghee and butter (to a lesser extent) are the only dairy products that are generally well-suited to a PCOS diet. This is because they contain only trace amounts of non-fat milk solids.
Is coconut milk good for PCOS? Yes. Coconut milk is generally well-tolerated by most individuals. It’s also a rich source of healthy fats, and important micronutrients.
Is shrimp good for PCOS? Yes. Unless you have a seafood allergy, shrimp/prawn can be an excellent protein source that’s quick and easy to cook.
Is muesli good for PCOS? Oats are somewhat suitable for PCOS because they’re gluten-free. But they’re also high in carbohydrates. When consumed in significant quantities, the oats in muesli can cause an unfavorable blood sugar response. This drives insulin resistance and subsequent hormone disruption. Because of the high sugar content, the addition of dried fruit to muesli makes this food ill-suited for women with PCOS.
What about rajma for PCOS? Beans and legumes are often valued as a source of protein, but women with PCOS need to be mindful that they are also rich in carbohydrates. The ingredients of a Rajma curry are generally fine for women with PCOS, but when consumed with significant rice portions, this dish can adversely impact insulin regulation. Higher fat, higher protein curry dishes are generally better for women with PCOS.
What about cashews or peanuts for PCOS? In the absence of allergies, both cashews and peanuts are well-suited for inclusion in a PCOS diet.
Since 2010, Kym Campbell has used evidence-based diet and lifestyle interventions to manage her PCOS. After getting her symptoms under control and falling pregnant naturally, Kym now advocates for dietary change as part of any PCOS treatment plan. Combining rigorous science and clinical advice with a pragmatic approach to habit change, Kym is on a mission to show other women how to take back control of their health and fertility. Read more about Kym and her team here.
This blog post has been critically reviewed to ensure accurate interpretation and presentation of the scientific literature by Dr. Jessica A McCoy, Ph.D. Dr McCoy has a master’s degree in cellular and molecular biology, and a doctorate in reproductive biology and environmental health. She currently serves as a University professor at the College of Charleston, South Carolina.
This blog post has also been medically reviewed and approved by Dr. Sarah Lee, M.D. Dr. Lee is a board-certified Physician practicing with Intermountain Healthcare in Utah. She obtained a Bachelor of Science in Biology from the University of Texas at Austin before earning her Doctor of Medicine from UT Health San Antonio.
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