June 2022. About this episode: Nutrition is a crucial foundation for performance. It underpins everything from preparation via fuelling and…
Do nuts have a glycaemic index (GI)?
Do nuts have a glycaemic index (GI)?
Nuts contain relatively small amounts of carbohydrate, and because of this, most nuts do not have a glycaemic index (GI).
The exceptions are chestnuts (GI = 54), pistachios (GI = 28), cashews (GI = 25) and peanuts (GI = 13), which are low in carbohydrate – but do have enough to be GI tested (1). With a GI rating below 55, all four of these nuts are considered ‘low GI’.
Table: The glycaemic index of nuts
|Nut|| Glycaemic Index |
| Carbohydrate |
*The University of Sydney. Glycaemic Index Research and GI News. Accessed 9 May 2022. Available at: https://glycemicindex.com/gi-search/
#Food Standards Australia New Zealand (2022). Australian Food Composition Database – Release 2. Canberra: FSANZ. Available at: www.foodstandards.gov.au
What is the glycaemic index?
The glycaemic index (GI) is a relative ranking of carbohydrates (between 0 and 100) based on how they affect blood glucose levels (1).
Lower GI foods are digested and absorbed more slowly by the body, resulting in a slower and smaller rise and fall in blood glucose levels. On the other hand, foods with a higher GI tend to result in faster and higher peaks and troughs in blood glucose levels.
|Low GI foods||≤ 55|
|Medium GI foods||56-69|
|High GI foods||≥70|
It’s generally best, day-to-day, to opt for more low and medium GI foods, but not to exclude high GI foods – as these can also be part of a healthy diet (2). And moderate to high GI foods may be helpful for refuelling after exercise (3).
Did you know? A low-GI diet has been shown to reduce the risk of type 2 diabetes and help in its management (4,5).
A role for nuts in lowering the GI of a meal
Nuts take time to digest, thanks to their complex plant cell walls, and the healthy fats and fibre they contain.
When nuts are combined with foods rich in carbohydrates, they slow the digestion of the entire meal – resulting in a slower and smaller overall rise in blood glucose levels (6-9). In other words, adding nuts to a meal slows the passage of food through the intestine, which lowers the rise of blood glucose levels after a meal.
Did you know? Eating nuts is linked with significantly higher intake of key nutrients, including fibre, vitamin E, iron, magnesium and phosphorus.
- The University of Sydney. Glycaemic Index Research and GI News. Accessed 9 May 2022. Available at: https://glycemicindex.com/gi-search/
- Diabetes Australia. Glycaemic index. Accessed 9 May 2022. Available at: https://www.diabetesaustralia.com.au/food-activity/eating-well/glycemic-index/
- Sports Dietitians Australia. Fact sheet: Glycaemic index and sports performance. Accessed 9 May 2022. Available at: http://www.sportsdietitians.com.au/wp-content/uploads/2015/04/GI_and_sports_performance.pdf
- Thomas, D., Elliott, EJ. Low glycaemic index, or low glycaemic load, diets for diabetes mellitus. Cochrane Database Syst Rev, 2009 (1): p. Cd006296.
- Chiavaroli, L., et al. Effect of low glycaemic index or load dietary patterns on glycaemic control and cardiometabolic risk factors in diabetes: Systematic review and meta-analysis of randomised controlled trials. BMJ, 2021. 374.
- Kendall, CW., et al., The glycemic effect of nut-enriched meals in healthy and diabetic subjects. Nutr Metab Cardiovasc Dis, 2011. 21, Suppl 1: S34-9.
- Kendall, C., et al. The impact of pistachio intake alone or in combination with high-carbohydrate foods on post-prandial glycemia. Eur J Clin Nutr, 2011. 65: 696–702.
- Josse, AR., et al. Almonds and postprandial glycemia—a dose-response study. Metab Clin Exp, 2007. 56(3):400-4.
- Lilly, LN., et al. The effect of added peanut butter on the glycemic response to a high-glycemic index meal: A pilot study. J Am Coll Nutr, 2019. 38(4):351-7.
Published May 16, 2022