Glycemic Load
Impact of a food portion on blood sugar, combining quality (GI) and quantity.
Formula
Live Calculator
MembersVariables
Example
GI 70, 30 g ⇒ GL = 21
How it works
Glycemic load estimates how much a specific portion of food is likely to raise blood glucose, not just how quickly the carbohydrate is absorbed. It combines glycemic index, which measures the blood-sugar impact of a standard amount of carbohydrate, with the actual grams of available carbohydrate in the serving, so a small serving of a high-GI food and a large serving of the same food can have very different effects. Dividing by 100 simply rescales the GI percentage-style value into a portion-based score.
When to use it
Use this when comparing real serving sizes of carbohydrate-containing foods, especially for meal planning in diabetes, sports nutrition, or diet analysis. It is most useful when the carbohydrate amount varies a lot between portions or foods with similar GI values.
Worked example, step by step
Suppose a snack has GI = 54 and contains 18 g of available carbohydrates. GL = (GI × C) / 100 GL = (54 × 18) / 100 GL = 972 / 100 GL = 9.72 So the glycemic load of the portion is 9.72, which is about 9.7.
Common mistakes to avoid
- Using total carbohydrate instead of available carbohydrate
- Forgetting that GI is based on a standardized carbohydrate amount, not the serving size itself
- Treating glycemic load as a percent rather than a scaled score for one portion
Did You Know?
Watermelon has a high GI (~72) but a low glycemic load per serving because a slice contains little actual carbohydrate.
Share this formula
More in Nutrition & Food
View allFood Energy (Atwater)
BasicTotal food energy in kilocalories from its macronutrients using the Atwater factors.
Calories from Protein
BasicEnergy contributed by protein at 4 kcal per gram.
Calories from Carbohydrate
BasicEnergy from carbohydrate at 4 kcal per gram.
Calories from Fat
BasicEnergy from fat at 9 kcal per gram — the most energy-dense macronutrient.
Calories from Alcohol
IntermediateEnergy from pure alcohol (ethanol) at 7 kcal per gram.
Kilocalories to Kilojoules
BasicConvert dietary Calories to the SI energy unit used on many food labels.