How We Source Our Glycemic Index Data

How glycemic index is measured

The standard method (ISO 26642) feeds a group of healthy volunteers a portion of the test food containing 50g of available carbohydrate, tracks their blood glucose over two hours, and compares the rise against the same amount of pure glucose (GI 100). The result is averaged across participants.

We classify foods using the standard cut-offs: low GI is 55 or below, medium is 56–69, and high is 70 or above. Glycemic load (GL) is then calculated per serving as GI × grams of carbohydrate ÷ 100 — see what GI and GL mean.

Where our 264 values come from

Each food page shows its own source next to the GI value, so you can always see whether a number was measured or estimated.

Why so many values are estimated

Only a fraction of Indian dishes have ever been clinically tested for GI. Plain staples like rice, wheat roti, dals and common fruits are well studied; regional dishes such as misal pav, chakuli pitha or paruppu usili mostly are not.

For untested dishes we estimate GI from the published values of their main carbohydrate ingredients and of similar tested foods, taking into account how the dish is prepared (fermented, fried, combined with dal or fat). Estimates are best used to compare foods and choose between options, not as exact figures.

Foods with no meaningful carbohydrate

GI can only be measured for foods that contain carbohydrate. Meat, fish, eggs, ghee and butter barely raise blood sugar, so we list them as GI 0. That shows their minimal blood-sugar effect; it isn't a laboratory result, and it says nothing about their calories or fat.

Nutrition values

Calories, carbohydrates, fiber, sugar, protein and fat are shown per typical Indian serving (e.g. 1 medium roti, 1 medium bowl of dal) and are based on standard recipes and Indian food composition data. Home recipes vary, so treat them as approximate.

Food images

Food photos on this site are AI-generated illustrations of a typical home-style serving. Each one is reviewed against the dish before it is published, but your own portion or recipe may look different — always go by the serving size stated on the page, not the picture.

Limits of the numbers

Even measured GI values differ between studies — white rice, for example, has been measured anywhere from the 50s to the 90s depending on variety and cooking. Your own response also depends on:

• Cooking method, and how long the food is cooked
• Ripeness, variety and processing
• What else is on the plate (protein, fat and fiber slow absorption)
• Portion size
• Your own metabolism and medication

If you have diabetes, a glucose meter or CGM reading after a meal is the best test of how a food affects you. See our disclaimer.

References

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. American Journal of Clinical Nutrition, 2021; 114(5): 1625–1632.Measured GI values for tested foods
2. University of Sydney, Glycemic Index Research Service — GI Database (glycemicindex.com).Measured GI values for tested foods
3. Longvah T, Ananthan R, Bhaskarachary K, Venkaiah K. Indian Food Composition Tables 2017. National Institute of Nutrition (ICMR), Hyderabad.Carbohydrate, fiber and nutrient composition of Indian foods
4. ICMR–National Institute of Nutrition. Dietary Guidelines for Indians, 2024.General dietary guidance for Indian diets
5. ISO 26642:2010. Food products — Determination of the glycaemic index (GI) and recommendation for food classification.GI testing method and low / medium / high cut-offs