Can changing your diet help with PCOS?

PCOS (Polycystic Ovarian Syndrome) is a term you’ve probably heard before, particularly if you are female. It is actually very common, affecting approximately 18-25% of Australian women. To put that in perspective, that’s more than half a million of us!

PCOS is a complex endocrine (hormonal) condition that is associated with infertility, and metabolic dysfunction.

How is PCOS diagnosed? 

In Australia, your Doctor will usually diagnose you with PCOS if you have at least two of the following signs and symptoms: the presence of ovarian cysts, an irregular or absent menstrual cycle, unexplained weight gain, unwanted hair, fatigue or low mood. However, this diagnosis will also depend on your individual circumstances so it is really important you don’t diagnose yourself based off this criteria!

While there is a genetic component that can contribute to the development of PCOS, lifestyle factors that result in weight gain (poor diet and low physical activity) play a major role in your developmental risk. Nevertheless, women who are not carrying excess weight can still develop PCOS.

What happens to your body when you have PCOS?

Something called “insulin resistance” plays a role in the development of PCOS. The mechanism of insulin resistance is really complex and not something I will go into for this blog post. But, broadly speaking, I like to think of insulin (which is a hormone) as a key that unlocks each cell of our body so that glucose can enter and be used for energy.

When you develop insulin resistance, it means that the insulin key has trouble opening the cell to let glucose in. Consequently, glucose stays inside the blood and causes havoc on your body in a number of ways. If you are carrying extra body weight, the insulin key is even more ineffective, which further exacerbates the issue.

Due to this faulty insulin key, women with PCOS are at an increased risk of type 2 diabetes, metabolic syndrome, cardiovascular disease, and cancer later in life.

Can changing your diet help with PCOS?

Research has shown that women with PCOS frequently describe problems with their appetite such as ‘craving’ sweet foods or always being hungry and needing to eat large portions to be satisfied. It is believed that this is related to the faulty insulin key we spoke about earlier. To clarify, if your body’s cells cannot get enough glucose (because it is sitting in your blood unable to enter), they think there is none available and send signals to your brain to tell you to eat more glucose to fuel your cells. And so the cycle continues.

So how can you stop this and improve your insulin resistance? There are a number of things you can do:


N-acetylcysteine (NAC) is a powerful antioxidant and amino acid. Some studies have shown that NAC can protect insulin receptors and influence insulin receptor activity and insulin secretion from pancreatic cells. Therapeutic doses of NAC in studies are 1.6 to 3 g daily.

Skip the processed foods and drinks

One of the best things you can do for yourself is to substitute any processed foods and drinks out of your diet for fresh foods. Go by the rule – if it grows naturally, and doesn’t come in a packet, eat it. Swap the soft drink for water; the chocolate bar for a handful of nuts; the white bread for seedy, good quality sourdough; the sausage roll or meat pie for a large, filling salad with roast vegetables, rice, lots of avocado and seeds. Choose healthy snacks such as fruit; carrot, celery or zucchini ‘sticks’ with dips like hummus or homemade salsa; or a tub of good quality, unsweetened yoghurt, instead of biscuits, cakes, pastries or potato crisps.

Prioritise vegetables in your day! Aim to eat different types and colours. Fill half your dinner plate with vegetables, and cook at home more often, as research shows this can ‘up’ your vegetable intake by more than half a serve a day. Care for yourself and you will be doing yourself a massive favour in the long run!

Eat foods with a lower Glycemic Load

Eating a diet that contains foods with a lower glycemic index and glycemic load have been shown to reduce metabolic markers associated with PCOS, even without weight loss. The glycaemic index (GI) is a ranking between 0-100 given to carbohydrate-containing foods to describe how quickly the carbohydrates are digested into glucose (sugar) and absorbed into our blood. The lower the GI, the slower the rise in blood glucose levels when the food is consumed. Most junk foods (candy, chips and cakes) have a high GI. Glycaemic load (GL) builds on the concept of GI but also considers the amount of food being eaten. This provides a more accurate picture of the overall effect the food has on blood glucose levels.

Try to focus on eating foods higher in unrefined carbohydrates (wholemeal sourdough bread, oats, barley and brown rice) earlier in the day and eating an afternoon and evening meal that is richer in protein, unsaturated fats and vegetables.


Both myo-inositol (MYO) and D-chiro-inositol (DCI) are showing promising results for PCOS. MYO in particular has been shown to improve insulin sensitivity as well as egg quality and ovulation. Inositols are pseudovitamins found in foods such as fruits, beans and buckwheat. MYO and DCI work as inositol-phosphoglycan mediators, or “secondary messengers” that regulate activities of hormones, including follicle-stimulating hormone, thyroid-stimulating hormone, and insulin. The therapeutic dosage is 2 to 4 g MYO daily with 50 to 100 mg DCI daily.

Get enough good fats

High quality poly-unsaturated fats can help your body to become more sensitive to insulin (to get that insulin key working better!). These fats include omega 3 fats, and the long chain plant version of these fats found in walnuts, and nuts and seeds. Try to include 3-4 serves of good fats each day via some olive oil, avocado, nuts and seeds or fish (if you eat it) about 3 times each week.

Vitamin B12

Are you taking Metformin for your PCOS? Results from the Diabetes Prevention Program Outcomes Study show that metformin affects the absorption of vitamin B12 by causing alterations of the vitamin B12-intrinsic factor complex in the gut. It’s recommended that women who take metformin have their vitamin B12 levels checked every six months and supplement with vitamin B12 if needed. The sublingual methylcobalamin form is best absorbed! Read more about the importance of B12 in my blog post here.

Please email me with any further questions to:

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