Data Sources & Licensing

1. Glycemic Index Data

Source: University of Sydney Glycemic Index Database — International Tables of Glycemic Index and Glycemic Load Values (Atkinson et al., Diabetes Care, 2021). This is the authoritative global reference for GI/GL values, containing measurements for over 4,000 individual food items tested under ISO 26642:2010 standards.

License: The GI values are compiled from published, peer-reviewed scientific literature. Our use is for educational and informational purposes under fair use / fair dealing provisions for scientific data reference. The complete dataset and methodology are described in the original publication (Atkinson et al., 2021, DOI: 10.2337/dc20-2623).

2. Nutrition Data

Source: USDA FoodData Central, SR Legacy (2018). This is the United States Department of Agriculture's standard reference database for food composition, providing comprehensive nutrient profiles for approximately 7,800 food items.

License: USDA FoodData Central data is in the public domain (CC0). The USDA explicitly states that its datasets are U.S. government works not subject to copyright. You are free to copy, modify, and distribute USDA nutrition data without restriction.

3. Derivative Estimates

Where direct GI measurements are not available, GlycemicWise provides estimated GI values using these methods:

  • Subcategory averages (Tier 3): Weighted mean GI of all ISO-tested foods in the same USDA food subcategory.
  • Low-carbohydrate inference (Tier 4): For foods with very low available carbohydrate content (<5g/100g), a conservative GI estimate is used based on the food's macronutrient composition.

All estimated values are clearly labeled on their respective food pages. See our Methodology page for the full estimation protocol.

4. Warning Thresholds

Sodium, saturated fat, and added sugar thresholds follow the FDA Daily Values and the American Diabetes Association's nutrition recommendations for diabetes management. Fiber thresholds reference the Institute of Medicine's Dietary Reference Intakes.

Last reviewed: July 31, 2026

Dietary reference — not medical advice. This page provides evidence-based dietary reference information for general educational purposes. It is not a substitute for professional medical advice, diagnosis, or treatment. Individual blood sugar responses vary significantly. Always check your blood glucose to understand your personal response to foods, and talk to your doctor or a registered dietitian before changing your diet. Data sources are cited above and publicly available from the USDA and the University of Sydney Glycemic Index Research Service.