Barcode and nutrition label scanner

How does barcode scanning work?

Scan the barcode on a packaged food, and SeeMeEat looks it up and shows the serving data along with the source it came from. Before you log, check two things: that the product on screen matches the package in your hand, and that the amount matches what you actually ate.

The second check matters more than it sounds. Every number on a Nutrition Facts label refers to one serving, and many packages hold several. In the FDA's own example, a frozen lasagna has 280 calories per serving and 1,120 in the whole package.

How does label reading work?

Point your camera at the Nutrition Facts panel, and SeeMeEat reads it on your phone. It then shows you every number it read, and you confirm or edit each one before logging. That makes it useful for products whose barcode doesn't bring up what you need.

Because the reading happens on the device and you check each value, you stay in control of what goes into your journal. A misread digit is easy to catch when the numbers are laid out for you to confirm.

Why does SeeMeEat show the data source?

So you can judge the entry for yourself. Packaged-food data can come from different places, and seeing the source and the serving size next to the numbers helps you spot an entry that doesn't match your package.

When is a barcode better than a photo?

Whenever the food came in a package. Label numbers are held to FDA limits, while a photo estimate has to judge the amount of food from the picture, which research such as Google's Nutrition5k study identifies as the largest source of error. Save photos for plates without a label, such as home cooking and restaurant meals.

What else can you log?

Almost anything. These come with SeeMeEat Pro, alongside unlimited photo scans:

• Food search across a catalog of about 4.1 million source-labeled reference and manufacturer-label foods, with adjustable quantities and favorites.
• Manual entry, for anything you already know the numbers for.
• Ranked smart repeats of things you log often.
• Meal Memory relogs of meals you've corrected and saved.
• AutoLog, which can schedule an exact meal you've already reviewed.

How accurate are the numbers on a label?

Close, with some legal room. U.S. rules treat a packaged food as mislabeled only if it holds more than 20 percent more calories than the label says. In a 2013 study of 24 popular snack foods, measured calories ran a median of 4.3 percent above the labels, well within that limit.

Labels are also rounded. Calories are rounded to the nearest 5 up to 50 and to the nearest 10 above that, so small differences between a label and a database entry are normal.