Whole wheat bread glycemic index
Whole wheat bread has a glycemic index of 75, which is high. A 30 g serving (1 slice) has a glycemic load of 8 (low).
Also known as: wholemeal bread, whole grain bread, brown bread
- Serving30 g
- Available carbs11 g
- Fiber1.8 g
- Sugars1.3 g
- Protein3.7 g
- Calories76 kcal
Serving: 1 slice.
What to know
Surprisingly, bread made from finely milled whole wheat flour has a GI as high as white bread (75 on average). What lowers the GI is intact grains and seeds you can see, not just the brown color. Look for dense, grainy loaves.
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 | 18 g | 14 | Medium |
| 100 g | 37 g | 28 | High |
| 30 g · 1 slice | 11 g | 8 | Low |
| 60 g · double serving | 22 g | 17 | Medium |
What the studies found
The value of 75 is the mean calculated by the authors of the International Tables of Glycemic Index (2021) across 24 studies. Results range from 61 to 96. 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.
- 61 · Spain 2013
- 64 · Australia 1996
- 65 · Canada 1988
- 66 · Germany 1980
- 67 · n/a 2006
- 67 · Canada 1985
- 68 · Canada 1985
- 69 · China 2005
- 70 · Canada 1985
- 70 · Canada 1983
- 70 · Australia 2001
- 72 · Canada 1983
- 72 · Denmark 1990
- 75 · Australia 2012
- 75 · Canada 1983
- 75 · Australia 1981
- 75 · Italy 2009
- 75 · South Africa 1984
- 77 · Sri Lanka 2009
- 77 · Australia 1986
- 78 · Australia 1989
- 85 · Malaysia 2009
- 88 · Kenya 1996
- 96 · Canada 2007
Whole wheat bread compared with other bread & bakery
Lower-GI swaps
Know the glycemic index of any meal from a photo
Tables work for single foods. The app estimates the GI and glycemic load of your whole plate, with real portions.
- Scan your plate or just describe it
- GI, glycemic load, calories and macros
- An AI nutritionist that knows your meals
Frequently asked questions
Is whole wheat bread low glycemic?
No. With a GI of 75, whole wheat bread is in the high range (70 or more). Low GI is 55 or less.
What is the glycemic load of whole wheat bread?
A 30 g serving (1 slice) has a glycemic load of 8, which is low. 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 whole wheat bread?
With a GI of 75 and a low glycemic load per serving, whole wheat bread usually fits a diabetes-friendly diet in normal portions. Everyone responds differently, so talk to your doctor or dietitian about your plan.
How many carbs are in whole wheat bread?
A 30 g serving has about 13 g of total carbohydrate, including 1.8 g of fiber, leaving 11 g of available carbohydrate (the part that raises blood sugar). Per 100 g: 42.7 g of carbohydrate.
Nutrition facts
| per 100 g | Serving (30 g) | |
|---|---|---|
| Calories | 252 kcal | 76 kcal |
| Carbohydrates | 43 g | 13 g |
| Available carbs | 37 g | 11 g |
| Fiber | 6 g | 1.8 g |
| Sugars | 4.3 g | 1.3 g |
| Protein | 12 g | 3.7 g |
| Fat | 3.5 g | 1.1 g |
Source: USDA FoodData Central, Bread, whole-wheat, commercially prepared (SR Legacy, FDC 172688). 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.