Whole Wheat Bread: GI, GL, Carbs & Blood Sugar Impact
Glycemic index of whole wheat bread (71), glycemic load, carbs per slice, and how to tell real whole-grain bread from 'wheat' bread.
Does Whole Wheat Bread Raise Blood Sugar?
True 100% whole-grain bread tests meaningfully lower (published GI around 71 with 6 g fiber per 100 g) than white bread. But labels lie by omission: “wheat bread” made mostly from white flour is nutritionally close to white bread.
How to Eat It
Check the label for “100% whole grain” and the fiber per slice (aim for 3 g+). Otherwise it is white bread with a marketing tan.
Nutrition Facts (Whole Wheat Bread)
| Nutrient | Per 100 g | Per serving |
|---|---|---|
| Calories | 247 kcal | 79 kcal |
| Carbohydrate | 41.3 g | 13.2 g |
| Fiber | 6 g | 1.9 g |
| Sugars | 6.9 g | 2.2 g |
| Protein | 13 g | 4.2 g |
| Fat | 3.4 g | 1.1 g |
Source: USDA FoodData Central (generic food item, per 100 g edible portion). Values may differ from brand-specific products.
Glycemic Index
Published GI: 71 (typical value).
Reported range: 51-74.
Evidence level: Moderate.
Note: Real 100% whole-grain bread tests lower; 'wheat' bread with mostly white flour does not.
Sources: International Tables of Glycemic Index and Glycemic Load Values (2008/2021); University of Sydney GI Database (glycemicindex.com). GI values are reported relative to a glucose reference.
Learn more: What is GI? · What is GL? · GI vs GL
Estimated Glycemic Load
GL ≈ 8.0 per 1 slice (32 g).
Calculation: GI (71) × available carbohydrate per serving (11.3 g = 41.3 g − 6 g fiber) ÷ 100. Calculated by DMSafeHaven; formula per standard published GL methodology.
- True whole-grain content
- Brand
- Portion size
GI values can vary with variety, ripeness, preparation and testing conditions. The value above is a typical published figure, not a universal prediction for every individual or every serving.