The power of low glycaemic index (GI) carbohydrates
A low-GI diet is one of the most helpful and evidence-based strategies for PCOS.
What does ‘low GI’ mean?
The glycaemic index refers to how quickly a carbohydrate-containing food raises your blood sugar.
- High-GI foods (white bread, sugary cereals, pastries) cause quick spikes.
- Low-GI foods (wholegrains, oats, beans, lentils, quinoa, rye, sweet potatoes) release sugars more slowly.
Why is this important in PCOS?
Because steady blood sugar levels → lower insulin levels → reduced androgen production → improved symptoms.
A major review found that low-GI diets were associated with:
- More regular menstrual cycles
- Reduced insulin resistance
- Improved cholesterol levels
- Better overall quality of life
But here’s the extra-good news:
Low-GI Carbohydrates Are Also Great for Your Gut Microbiome!
Many low-GI foods are also high in fibre, and fibre is your gut microbes’ favourite fuel.
Why does this matter?
When fibre reaches your large intestine, your gut bacteria ferment it into short-chain fatty acids (SCFAs) such as butyrate. SCFAs:
- Reduce inflammation
- Strengthen the gut barrier
- Improve insulin sensitivity
- Support healthy appetite regulation
- May positively influence reproductive hormones
So when you choose low-GI wholegrains rather than refined ones, you’re not just supporting blood glucose, you’re also feeding the very microbes that may help regulate PCOS hormones from the inside out.
Examples of low-GI, gut-friendly carbs:
- Oats
- Wholegrain and rye bread
- Lentils and beans
- Quinoa
- Farro, bulgur wheat and barley
- Sweet potatoes
- Brown or wild rice
Aim for variety, as different types of plant fibres feed different microbes.
