Glycemic Load Calculator (Meal GL and Average Glycemic Index)

What this tool does

The glycemic index ranks foods by how fast they raise blood glucose, but it is measured on a portion with 50 g of carbohydrate, which is rarely what you eat. Glycemic load fixes that by multiplying the index by the grams of carbohydrate actually in your portion and dividing by 100, an idea introduced by Harvard researchers in 1997. Per serving, a glycemic load of 10 or less is usually called low, 11–19 medium and 20 or more high, which is why watermelon, high in index but with little carbohydrate per slice, has a modest load. Take GI values from a published table such as the University of Sydney database, because they vary with variety, ripeness and cooking.

Formula

GL = GI × available carbohydrate (g) ÷ 100 · meal GI = Σ(GI × carbohydrate) ÷ Σ carbohydrate

Variables

Worked example

Limitations

• This tool is informational only. It does not diagnose, treat or replace a qualified health professional. Speak to a doctor before making decisions about your health.
• The default values are typical reference figures, not measurements of your situation. Replace them with your own data whenever you have it.