Sources and original illustrations

Primary references and the limits of this educational collection.

Primary references

• USDA FoodData Central downloadable datasets — The original SR Legacy CSV archive, its final 2018 release and the source of the searchable food records.
• USDA FoodData Central data-type documentation — Differences among historical generic reference data, foundation foods and branded label data.
• FDA: How to understand and use the Nutrition Facts label — Serving amounts, calories, package servings and the distinction between a label serving and an individual recommendation.
• FDA: Menu labeling requirements — The scope of US chain-restaurant menu calorie information and additional written nutrition information.

Original visual material

The diagrams in this edition are original SVG illustrations explaining the sequence or decisions in each guide. They do not show a laboratory experiment, a personal trip or a tested product result. No photographs from the linked sources are reproduced.

Check the source in context

References were consulted during preparation of this edition. A source may cover a broader or narrower question than a particular guide; the support notes above explain why it is listed. Read the original for methodology, exceptions and updates.