Low GI Diet for PCOS: What Does This Actually Mean?

Written By Rania Salman

If you’ve been diagnosed with PCOS, chances are you’ve come across advice recommending a low GI diet to help manage symptoms. But what does that actually mean in real life — and how do you apply it without obsessing over food rules?

Let’s break it down in a simple, practical way.

What happens when you eat carbohydrates?

Carbohydrates include foods such as bread, rice, pasta, noodles, potatoes, starchy vegetables, fruit, and sweet-tasting foods.

When you eat carbohydrates, your digestive system breaks them down into glucose, which enters your bloodstream. As blood sugar levels rise, the pancreas releases insulin — a hormone that helps glucose move from the blood into your cells, where it’s used for energy.

In around 70–80% of women with PCOS, the body’s cells are less responsive to insulin (a condition known as insulin resistance). This means glucose doesn’t move into the cells as efficiently, leading to higher and more fluctuating blood sugar levels. Over time, this can worsen PCOS symptoms. This is where a low GI approach can be helpful.

What is the Glycaemic Index (GI)?

GI stands for glycaemic index. It’s a scale from 0–100 that ranks carbohydrate-containing foods based on how quickly and how much they raise blood sugar levels after eating.

  • High GI foods are digested quickly and cause rapid rises in blood sugar

  • Low GI foods are digested more slowly, leading to a steadier rise in blood sugar

In general:

  • Refined and processed carbohydrates tend to be higher GI

  • Less processed, fibre-rich carbohydrates tend to be lower GI

However, choosing low GI foods isn’t as simple as just switching to wholegrains.

What affects the GI of a food?

Several factors influence how a carbohydrate affects your blood sugar:

  • Processing: Highly processed carbs (e.g. white bread, finely milled grains) are digested faster than intact grains like oats or brown rice

  • Fibre: Fibre slows digestion and helps stabilise blood sugar levels

  • Ripeness: Riper fruits and vegetables contain more easily digestible carbohydrates

  • Fat, protein & acid: Adding protein, fats, or acids (such as lemon juice or vinegar) slows glucose absorption when foods are eaten as part of a meal

  • Cooking methods: Overcooking foods (e.g. very soft pasta) increases GI — aim for pasta cooked al dente

  • Cooling & reheating: Cooked carbs that are cooled and reheated form resistant starch, which behaves more like fibre and reduces blood sugar spikes

Is GI the full picture?

Not quite.

GI tells us how quickly a carbohydrate affects blood sugar, but not how much carbohydrate is in a portion. This is where glycaemic load (GL) comes in.

GL takes into account:

  • The GI of a food

  • The amount of carbohydrate it contains

Some foods may be high GI but contain very little carbohydrate, meaning their overall impact on blood sugar is small.

That said — calculating GL for every food is not practical or necessary for most people.

So what should you actually focus on?

Rather than getting caught up in numbers, here’s what works best in practice for PCOS:

  • Choose carbohydrates in their whole or minimally processed form most of the time

  • Build balanced meals by including:

    • Protein

    • Healthy fats

    • Plenty of vegetables

  • Balance snacks to avoid sharp blood sugar spikes

A low GI approach for PCOS isn’t about cutting out carbohydrates or following rigid food rules. It’s about how you combine foods, how processed they are, and creating meals that support more stable blood sugar levels.

If you’re struggling with your diet or PCOS symptoms and want personalised, evidence-based support, click here to book a free discovery call to find out how I can help.

Rania Salman
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