Ask a Nutritionist: Do I have to cut out carbs if I have PCOS?

Hey Jess! There’s so much conflicting advice out there about carbs and PCOS. Do I really need to cut them out completely to manage my symptoms, or is there a better approach?

Navigating nutrition advice for PCOS can feel like trying to solve a puzzle with missing pieces. One day you’re told that cutting out carbs is the key, the next it’s a more balanced approach. With many opinions circulating it’s tough to know what’s best for you, but one thing is clear:  there’s no one-size-fits-all solution.

PCOS affects 1 in 10 people with ovaries, and its symptoms, like hormonal imbalances, weight gain, and irregular periods, can vary from person to person. That’s why it’s important to find a dietary approach that works for you. Let’s take a closer look at how carbs play a role, and whether cutting them out is the answer for everyone. 

What exactly is PCOS?

Polycystic Ovary Syndrome (PCOS) is a common hormonal condition that affects those with uteruses who are of reproductive age, often causing symptoms such as irregular or absent periods, difficulty becoming pregnant, acne or oily skin, and weight gain.  A key feature is the overproduction of androgens, which contributes to the development of insulin resistance. This means the body's cells become less responsive to insulin, leading to higher levels of insulin in the blood. This can result in symptoms like fatigue, carbohydrate cravings, and sleep disturbances. People with PCOS may find weight management more challenging due to factors like insulin resistance and increased cravings.

Does low-carb advice really help with PCOS? What does the research say?

The idea that reducing carbohydrate intake can help manage PCOS has gained traction over the years. Research, like this meta-analysis, suggests that low-carb diets can lead to reductions in body mass index (BMI) and improvement in insulin resistance, both critical factors for anyone with PCOS. Another study on the ketogenic Mediterranean diet—which combines principles from both the ketogenic (keto) diet and the Mediterranean diet—for PCOS showed that after 12 weeks, participants experienced significant weight loss, reductions in BMI, and improvements in glucose and insulin levels. However, both studies have clear limitations, small sample sizes (only 14 out of 24 participants completed the second study), short intervention periods, high dropout, and variations in diet types. It’s therefore difficult to draw definitive conclusions, and the evidence supporting low-carb diets for PCOS remains limited.

Is it about carb quality rather than quantity?

When managing PCOS, it’s less about cutting out carbs altogether and more about choosing the right ones. Opting for those with a low glycaemic index (GI) is key as these are digested more slowly, helping to maintain stable blood sugar and insulin levels. Think whole grains like quinoa and oats, starchy vegetables like sweet potatoes, and plenty of fruits and legumes. Research supports this approach, suggesting that low GI diets can improve weight management, insulin sensitivity, and even menstrual regularity in those with PCOS. For instance, a 12-week low-GI dietary intervention was shown to improve insulin sensitivity and fatty acid levels in individuals with PCOS, highlighting the potential benefits of this strategy.  

What other dietary factors could you consider?

While there isn't a single “best” diet for managing PCOS, research suggests that various approaches can effectively support symptom control. Pairing complex carbohydrates with foods rich in protein and fibre can slow the release of sugar into the bloodstream, reducing the amount of insulin your body releases. Additionally, studies indicate that a high-protein, low-glycaemic load diet can significantly improve insulin sensitivity, reduce inflammation, and lower androgen levels, offering a targeted approach for symptom management in people with PCOS.

Back to the original question: Do I need to cut carbs out entirely?

While low-carb diets are often suggested for managing PCOS, it’s important to note that research on their long-term effectiveness is limited, and they are not universally recommended. Instead of elimination, focusing on carb quality and tailoring your diet to your needs is more sustainable and essential for people with PCOS, as everyone’s needs are different. If you are struggling with symptom management, seeking advice from your GP or a registered dietitian can provide you with the professional guidance needed to find what works best for you.

Words: Jessica Stansfield, Registered Nutritionist, Huel Nutrition Manager