Bread Glycemic Index Comparison: 30+ Bread Types Ranked by GI
Glycemic index of 30+ bread types including white, whole wheat, sourdough, rye, pumpernickel, and gluten-free. See which breads spike blood sugar least.
TL;DR: Bread GI ranges from 41 (pumpernickel) to 95 (French baguette). The biggest factors are grain density, fermentation, and how finely the flour is milled. Sourdough, pumpernickel, and true whole grain breads are the best choices. Standard whole wheat bread (GI 69) is only marginally better than white (GI 75).
How to Use This Bread GI Comparison
This chart ranks 30+ bread types by glycemic index, from lowest to highest. It includes common grocery store breads, artisan varieties, flatbreads, and specialty options.
For each bread, the GI value, typical serving, carbohydrate content, and glycemic load are provided. Since bread servings vary significantly (a thin slice of pumpernickel versus a large bagel), the GL column gives you the real-world impact per serving.
Use this reference when choosing bread for sandwiches, toast, or meal accompaniments. The differences are substantial: the right bread choice can cut your glycemic load in half or more.
Complete Bread Glycemic Index Table
| Bread Type | GI | Serving | Carbs (g) | GL | GI Rating |
|---|---|---|---|---|---|
| Flour tortilla, white | 30 | 1 medium (35g) | 18 | 5 | Low |
| Pumpernickel | 41 | 1 slice (30g) | 12 | 5 | Low |
| Sprouted grain (Ezekiel-style) | 36 | 1 slice (34g) | 15 | 5 | Low |
| Sourdough, whole wheat | 48 | 1 slice (30g) | 12 | 6 | Low |
| Dark rye (whole kernel) | 50 | 1 slice (30g) | 12 | 6 | Low |
| 100% stone-ground whole wheat | 51 | 1 slice (30g) | 12 | 6 | Low |
| Corn tortilla | 52 | 1 medium (30g) | 12 | 6 | Low |
| Sourdough, white | 54 | 1 slice (30g) | 14 | 8 | Low |
| Multigrain, dense, seeded | 54 | 1 slice (38g) | 14 | 8 | Low |
| Oat bread | 55 | 1 slice (30g) | 13 | 7 | Low |
| Pita, whole wheat | 56 | 1 small (30g) | 15 | 8 | Medium |
| Pita, white | 57 | 1 small (30g) | 17 | 10 | Medium |
| Flaxseed bread | 55 | 1 slice (30g) | 10 | 6 | Low |
| Light rye bread | 63 | 1 slice (30g) | 14 | 9 | Medium |
| Barley bread | 55 | 1 slice (30g) | 13 | 7 | Low |
| Spelt bread | 54 | 1 slice (30g) | 13 | 7 | Low |
| Croissant | 67 | 1 medium (57g) | 26 | 17 | Medium |
| Whole wheat bread (commercial) | 69 | 1 slice (30g) | 13 | 9 | Medium |
| Hamburger bun | 61 | 1 bun (43g) | 22 | 13 | Medium |
| Gluten-free, multigrain | 63 | 1 slice (30g) | 13 | 8 | Medium |
| Naan bread | 71 | 1 piece (60g) | 33 | 23 | High |
| Gluten-free, white | 71 | 1 slice (30g) | 14 | 10 | High |
| Cornbread | 71 | 1 piece (55g) | 28 | 20 | High |
| Bagel, white | 72 | 1 medium (70g) | 35 | 25 | High |
| Ciabatta | 73 | 1 slice (30g) | 15 | 11 | High |
| Kaiser roll | 73 | 1 roll (57g) | 28 | 20 | High |
| White bread | 75 | 1 slice (30g) | 14 | 11 | High |
| Waffles | 76 | 1 waffle (75g) | 33 | 25 | High |
| English muffin, white | 77 | 1 muffin (57g) | 26 | 20 | High |
| Breadsticks | 78 | 4 sticks (30g) | 19 | 15 | High |
| French baguette | 95 | 1 slice (30g) | 15 | 14 | High |
Why Bread GI Varies So Much
The 54-point spread between pumpernickel (41) and baguette (95) comes down to four factors:
1. Grain Particle Size
Finely milled flour exposes more starch surface area to digestive enzymes, allowing rapid glucose release. Coarsely ground or intact grains (like the cracked rye kernels in pumpernickel) resist digestion.
| Milling Level | Example | Typical GI |
|---|---|---|
| Intact/cracked kernels | Pumpernickel, sprouted grain | 36-41 |
| Coarse stone-ground | Stone-ground whole wheat | 51-55 |
| Fine whole wheat flour | Commercial whole wheat | 69 |
| Fine white flour | White bread | 75 |
| Ultra-fine white flour | French baguette | 95 |
2. Fermentation
Sourdough fermentation produces lactic and acetic acids that slow starch digestion and lower postprandial glucose response. The longer the fermentation, the greater the effect.
| Bread | Fermentation | GI |
|---|---|---|
| Sourdough, whole wheat | Long (12-24 hr) | 48 |
| Sourdough, white | Long (12-24 hr) | 54 |
| Commercial whole wheat | Rapid yeast (1-2 hr) | 69 |
| Commercial white | Rapid yeast (1-2 hr) | 75 |
3. Added Seeds, Fiber, and Fat
Seeds and nuts add fat and fiber that slow digestion. Dense, seeded breads consistently test lower than their plain counterparts.
4. Moisture and Density
Lighter, airier breads (baguettes, ciabatta) have more exposed surface area and less density, leading to faster digestion. Dense, compact breads (pumpernickel, sprouted grain) are the opposite.
Best Breads for Blood Sugar Management
Based on the data, these are the optimal bread choices ranked by glycemic impact:
| Rank | Bread | GI | Why It Works |
|---|---|---|---|
| 1 | Sprouted grain (Ezekiel) | 36 | Intact sprouted kernels resist digestion |
| 2 | Pumpernickel | 41 | Cracked rye kernels, dense structure, acidic dough |
| 3 | Sourdough, whole wheat | 48 | Long fermentation + whole grain |
| 4 | Dark rye (whole kernel) | 50 | Intact rye kernels, dense crumb |
| 5 | Stone-ground whole wheat | 51 | Coarse milling preserves starch structure |
| 6 | Sourdough, white | 54 | Acid fermentation compensates for refined flour |
| 7 | Seeded multigrain | 54 | Seeds add fat and fiber |
How to Read This Chart
Bread GI falls into the standard three-tier classification:
-
Low GI (55 or below): Pumpernickel, sourdough, sprouted grain, dark rye, and well-made whole grain breads. These produce a slow, sustained glucose response and are the best daily choices.
-
Medium GI (56-69): Pita bread, croissants, commercial whole wheat, and light rye. These are not terrible choices but offer less blood sugar stability than the low-GI options. Pairing with protein and fat helps.
-
High GI (70 or above): White bread, baguettes, bagels, English muffins, naan, and most gluten-free breads. These produce rapid glucose spikes. If you eat them, combine with protein, fat, or vinegar-based dressings to slow absorption.
Note that serving size dramatically affects real-world impact. One slice of white bread (GL 11) is medium GL, but a large bagel (GL 25) is high GL. The GL column accounts for this.
Key Takeaways
- “Whole wheat” is not the slam dunk you think. Commercial whole wheat bread (GI 69) is only 6 points lower than white bread (75). The fine milling eliminates most of the benefit of the whole grain.
- Sourdough is the single best bread modification for blood sugar. It lowers GI by about 20 points regardless of the flour type. A white sourdough (54) beats commercial whole wheat (69).
- Gluten-free bread is generally high GI. Most GF breads use rice flour and tapioca starch, which are high GI. Seek out GF breads made with almond flour, coconut flour, or seeds.
- Density and chewiness correlate with lower GI. The harder you have to chew a bread, the slower it digests. Pumpernickel and sprouted grain breads require real chewing; baguettes dissolve quickly.
- The bagel problem. A single white bagel (GL 25) has more glycemic impact than two slices of sourdough (GL 16 total). Size matters as much as type.
Everyone’s glucose response is different. What spikes one person may be fine for another. Glycemic Snap uses AI to analyze photos of your meals and predict your glucose response, including a blood sugar curve prediction and personalized swap suggestions. Download for iOS or Android to discover your personal glycemic profile.
Related Resources
Track Your Personal Glucose Response
Everyone's glucose response is different. What spikes one person may be fine for another. Glycemic Snap uses AI to analyze photos of your meals and predict your glucose response, including a blood sugar curve prediction and personalized swap suggestions.
Frequently Asked Questions
What bread has the lowest glycemic index?
Pumpernickel bread has the lowest GI of common breads at 41, followed by sourdough whole wheat (48), dark rye (50), and 100% whole grain (51). The heavy, dense structure and acid content of pumpernickel slow digestion significantly.
Is sourdough bread really better for blood sugar?
Yes. The lactic acid produced during sourdough fermentation slows starch digestion and gastric emptying. White sourdough (GI 54) is about 20 points lower than regular white bread (GI 75). Whole wheat sourdough (48) is even better.
Is whole wheat bread actually low glycemic?
Not necessarily. Commercial whole wheat bread has a GI of 69, which is medium-high. The fine milling of modern whole wheat flour means it digests nearly as fast as white flour. Look for bread with visible whole grains, seeds, or choose sourdough for genuinely lower GI.