Spend any time in the low-carb aisle, and you'll spot it: "0 GI" in bold letters. It's a claim that sounds impressive, but what does it actually tell you? And does a low number always mean a better choice?

Let's break it down.

What Is the Glycaemic Index?

The Glycaemic Index, or GI, is a scale from 0 to 100 that ranks carbohydrate-containing foods by how quickly they raise blood glucose levels. Pure glucose sits at the top with a score of 100, and other foods are compared against it.

Foods generally fall into three bands:

• Low GI: 55 or under
• Medium GI: 56 to 69
• High GI: 70 and above

A high-GI food is digested quickly and can send blood sugar climbing fast. A low-GI food is broken down more slowly, leading to a gentler rise.

So What Does "0 GI" Mean?

A score of zero means the ingredient doesn't raise blood glucose in the way sugar does. That's why sweeteners such as erythritol, stevia and monk fruit are described as 0 GI: the body doesn't process them like ordinary sugar, so they don't cause the same blood sugar response.

Table sugar, by comparison, typically scores somewhere in the mid-60s depending on the source. Swapping it for a 0 GI alternative is one of the simplest ways to sweeten food without that spike.

Why It Matters on a Low-Carb Diet

For anyone following a ketogenic lifestyle, or managing blood sugar for health reasons, GI is a useful shortcut. It helps you compare ingredients quickly, and it explains why "natural" doesn't always mean "gentle". Honey and dates, for example, are natural, but they still contain plenty of sugar.

What GI Doesn't Tell You

GI is helpful, but it isn't the whole picture, so it's worth keeping a few things in mind.

1. It Isn't a Calorie Count

A food can have a low GI and still be high in calories or fat. GI measures blood sugar response only.

2. Portion Size Still Matters

GI ranks how fast a carbohydrate acts, not how much of it you're eating. Glycaemic Load takes both into account, which gives a fuller view of a real-life portion.

3. Foods Without Carbs Have No GI

Meat, fish, eggs and oils contain little or no carbohydrate, so they aren't given a GI score at all.

4. Everyone Responds Differently

Blood sugar responses vary from person to person, and what you eat alongside a food can change the result. If you're managing diabetes or another condition, speak to your GP or dietitian for guidance that suits you.

5. Some Sweeteners Suit Some People Better

Sugar alcohols such as erythritol can cause digestive discomfort in some people, particularly in larger amounts. Starting with small quantities lets you see what works for you.

How to Read Labels with Confidence

When you're comparing products, look beyond the headline claim. Check the ingredients list, the total carbohydrate figure and the serving size. A "0 GI" sweetener paired with a hidden sugar filler defeats the point, so simple, transparent ingredients are your best friend.

Putting It into Practice

Understanding GI puts you in control. It helps you choose ingredients that fit your goals and cut through the marketing noise.

Ready to swap your sugar for something smarter? Explore our range of 0 GI sugar alternatives, or book a consultation with our nutritionist for personalised guidance.