Are a “high-carb” diet and a “high-GI” diet the same?

No, they are not the same.

A high-carbohydrate diet is when more than 60% of your daily calories come from carbohydrate foods. In sports nutrition, a high-carbohydrate diet is when you eat between 7 and 12 grams of carbohydrate per kilogram of body weight a day.

In other words, a high-carb diet is when most of the foods you eat are carbohydrates.

Now, these carbohydrates can have a low, moderate or high GI. The GI indicates how quickly or how slowly a food raises your blood glucose. A slow release makes that food low-GI – and a fast release, high-GI.

Basically, you can be on a high-carb diet with a low GI!

If, for instance, 80% of the calories you eat are from fruit, vegetables, beans and wholegrains, you would say that you are on a high-carb but low-GI diet!

But isn’t saying “low-GI” and “low-carb” the same thing?

No, it isn’t. Most people get confused with this.

You’d use the term “low-GI” when a food raises your blood sugar slowly and steadily. Some people use the expression “slow” carb to indicate that a carbohydrate has a low GI.

On the other hand, “low-carb” means that most of the foods you eat aren’t carbohydrates.
If for a period of time you reduce your carbohydrate intake, you could say that you are on a “low-carb diet.”

Conversely, if you’re eating a plant-based diet of mostly vegetables and legumes, you would then be on a “high-carb, low-GI diet.”

This is because vegetables and legumes (beans, lentils) are essentially carbs, even though most of them have a low GI.

The bulky fibre in vegetables is a carbohydrate too. Although fibre has zero calories and provides no energy, it is technically a carbohydrate!

To check the GI of specific foods, you can visit this Harvard resource (GI of common foods) or use this search tool developed by The University of Sydney.

AUTHOR: Alex Ruani, Research Director

Updated on: 15/10/2026