Helsa Health

    Breads · Glycemic index

    Does white bread spike blood sugar?

    Not much in a small portion. White bread has a high GI of 73, but a 29 g serving (1 slice) has a low glycemic load of 10. White bread is made from refined flour that is digested quickly. A single slice holds a modest amount of carbohydrate, but the load climbs with every extra slice, roll or bagel.

    Key numbers

    Glycemic index
    73
    High GI
    Glycemic load
    10
    Low GL
    Available carbs
    14 g
    0.8 g fiber
    Serving
    1 slice
    29 g · fresh

    GI vs GL for white bread

    The glycemic index (GI) compares how fast the carbohydrate in a food raises blood sugar against pure glucose (100), using a fixed amount of carbohydrate. The glycemic load (GL) adds the other half of the story — how much carbohydrate a normal serving actually contains: GI × available carbs Ă· 100. For white bread: 73 × 14 g Ă· 100 ≈ 10.

    That figure is an average reported in the 2021 international GI tables (“White wheat flour bread, mean of 35 foods”). Toasting may help a little: three toasted white breads averaged 60 in the 2008 tables, against 75 for 16 untoasted white breads.

    Eating a different amount? Work out the glycemic load of your portion.

    How to eat white bread with less of a spike

    • Toast it: three studies of toasted white bread averaged a GI of 60 in the 2008 tables, compared with 75 for untoasted white bread.
    • Make open sandwiches with one slice instead of two, piled with eggs, fish, chicken or hummus and salad.
    • Add something acidic, such as a salad with a vinegar dressing — meals containing acid are converted into sugar more slowly.

    Lower-GI swaps

    Compare with

    See all 67 foods in the glycemic index table

    Frequently asked questions

    What is the glycemic index of white bread?

    White bread has a glycemic index of 73, which is high. That figure is an average reported in the 2021 international GI tables (“White wheat flour bread, mean of 35 foods”). A 29 g serving (1 slice) contains about 14 g of available carbohydrate, giving a glycemic load of 10 (low).

    Is white bread good for prediabetes?

    One slice of white bread with protein and vegetables is a small load, but sandwiches, rolls and stacks of toast add up quickly. Grainy, seeded or rye breads with visible whole grains are better everyday choices.

    Is toast lower GI than fresh bread?

    A little, according to the available studies. In the 2008 international tables, three tests of toasted white bread averaged 60, compared with an average of 75 for 16 tests of untoasted white bread. Toasting doesn't remove any carbohydrate, so the portion still matters.

    Sources

    GI values come from the international GI tables; carbohydrate and fiber per serving are calculated from USDA FoodData Central.

    1. 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, Supplemental Table 1
    2. USDA FoodData Central, FDC ID 174924: Bread, white, commercially prepared (includes soft bread crumbs)
    3. Atkinson FS, Foster-Powell K, Brand-Miller JC. International tables of glycemic index and glycemic load values: 2008 — online appendix, Table A1
    4. Harvard T.H. Chan School of Public Health, The Nutrition Source — Carbohydrates and Blood Sugar

    Data last checked .

    Real meals aren’t single foods

    GI tables measure one food eaten on its own. Helsa’s photo and voice meal logging uses AI nutrition analysis to estimate how a whole meal — the rice with the curry, the toast with the eggs — is likely to affect your blood sugar, with no CGM needed. Helsa is free to download, with optional premium features.

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