Cornflakes glycemic index
Cornflakes has a glycemic index of 80, which is high. A 30 g serving (1 bowl, dry) has a glycemic load of 18 (medium).
Also known as: corn flakes
- Serving30 g
- Available carbs23 g
- Fiber1.1 g
- Sugars2.8 g
- Protein1.9 g
- Calories110 kcal
Serving: 1 bowl, dry.
What to know
Cornflakes are one of the highest-GI breakfast cereals, averaging 80 across 10 studies. Swapping to muesli, rolled oats or a bran cereal lowers the GI of breakfast considerably.
Glycemic load by portion size
GI stays the same whatever you eat, but glycemic load scales with the amount: eating twice as much doubles the effect on blood sugar.
| Amount | Available carbs | Glycemic load | |
|---|---|---|---|
| 50 g | 38 g | 30 | High |
| 100 g | 76 g | 61 | High |
| 30 g · 1 bowl, dry | 23 g | 18 | Medium |
| 60 g · double serving | 46 g | 36 | High |
What the studies found
The value of 80 is the mean calculated by the authors of the International Tables of Glycemic Index (2021) across 23 studies. Results range from 52 to 132. That spread is normal: GI changes with variety, ripeness, cooking and processing, and between labs.
Each dot is one study. Green dots followed the ISO 26642 standard method.
- 52 · Korea 2018
- 64 · Australia 2014
- 66 · France 2019
- 72 · Australia 1999
- 72 · New Zealand 2000
- 74 · China 2005
- 74 · China 2005
- 75 · Canada 1992
- 77 · France 2019
- 77 · France 2019
- 77 · Australia 1984
- 79 · China 2005
- 79 · China 2005
- 80 · Canada 1981
- 81 · Australia 2014
- 82 · Australia 2010
- 87 · Canada 1983
- 88 · Nigeria 2015
- 92 · USA 1987
- 93 · Thailand 2019
- 93 · France 2002
- 105 · Thailand 2020
- 132 · USA 2002
Cornflakes compared with other breakfast cereals
Lower-GI swaps
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Frequently asked questions
Is cornflakes low glycemic?
No. With a GI of 80, cornflakes is in the high range (70 or more). Low GI is 55 or less.
What is the glycemic load of cornflakes?
A 30 g serving (1 bowl, dry) has a glycemic load of 18, which is medium. Glycemic load combines GI with the amount of carbohydrate in the portion: 10 or less is low, 11 to 19 medium and 20 or more high.
Can people with diabetes eat cornflakes?
With a GI of 80 and a medium glycemic load per serving, cornflakes can be part of a diabetes-friendly diet with attention to portion size and pairing it with protein, fat or fiber. Everyone responds differently, so talk to your doctor or dietitian about your plan.
How many carbs are in cornflakes?
A 30 g serving has about 24 g of total carbohydrate, including 1.1 g of fiber, leaving 22.8 g of available carbohydrate (the part that raises blood sugar). Per 100 g: 79.5 g of carbohydrate.
Nutrition facts
| per 100 g | Serving (30 g) | |
|---|---|---|
| Calories | 365 kcal | 110 kcal |
| Carbohydrates | 80 g | 24 g |
| Available carbs | 76 g | 23 g |
| Fiber | 3.5 g | 1.1 g |
| Sugars | 9.4 g | 2.8 g |
| Protein | 6.4 g | 1.9 g |
| Fat | 1.6 g | 0.5 g |
Source: USDA FoodData Central, Cereal, corn flakes, plain (FNDDS, FDC 2708453). Available carbohydrate = total carbohydrate minus fiber.
Sources: Atkinson FS, Brand-Miller JC, Foster-Powell K, Buyken AE, Goletzke J. International tables of glycemic index and glycemic load values 2021: a systematic review. Am J Clin Nutr. 2021;114(5):1625–1632. USDA FoodData Central. How we calculate each value: Methodology & sources.
Data last reviewed 2026-09-29.