A five-step check before trusting a scanned nutrition label

A captured label is most useful when you can trace each extracted number back to the package. Before saving a comparison from any scanning workflow, check the product, column, nutrient name, value, and unit. The worksheet below is an editorial checking method, not a measured accuracy claim about any app.

1. Match the package you actually hold

Write down the product name, flavor, pack size, and market. A search result for a similar package is not evidence that the numbers match yours. Save the date checked and, if useful, a readable photo of the full panel. Keep the product identity next to the numbers so that an update can be traced later.

2. Capture the column heading

A panel may show a serving and a whole-package column. FDA guidance explains these different presentations and the role of serving information. FDA serving-size guidance. Copy the heading with its values. Do not take a nutrient from one column and a serving weight from another.

For example, suppose the first column describes 40 g and lists 120 mg sodium, while the package column describes 120 g and lists 360 mg sodium. Pairing 360 mg with 40 g would calculate 900 mg per 100 g. The correctly paired values both give 300 mg per 100 g. This invented example shows how one column mismatch can triple the result.

3. Read the nutrient name and unit aloud

Check whether the row says total sugars or added sugars, sodium or salt, and g or mg. Preserve decimal points. An extracted 1.5 g is not interchangeable with 15 g. A quick read-back against the photograph can expose a mismatch before it reaches a saved comparison.

4. Recalculate one simple relationship

In the example above, the package weighs three stated servings, so the sodium figures should have the same threefold relationship at the displayed precision: 120 × 3 = 360. The FDA's label-reading examples demonstrate scaling nutrient quantities when the consumed amount changes. FDA explanation and examples. A mismatch is a reason to inspect the original, not a reason to silently replace a number.

5. Keep uncertainty visible

Record each uncertain field as unreadable or unavailable. Do not guess a cropped decimal or fill a missing nutrient with zero. If the panel is curved or reflective, take another photograph with the relevant section flat and fully visible. Retain the original value separately from a manually corrected transcription.

A practical saved row has six fields: product, source photo, serving basis, nutrient, amount with unit, and verification note. Once those agree, run the comparison. This check supports transcription and arithmetic; it does not establish allergen safety, diagnose a condition, or validate every statement about a product.