In the case you scanned a barcode, and it shows the wrong product information connected, please proceed as follows: 

Scroll down on the product page that pops up after you have scanned the code until you see the link Wrong result for the barcode? 

Tap on the link and you will come to a page offering the search function. Type in the product name that should be connected to the barcode and choose the correct one from the list. Then - in order to connect the code with the product - tap on Connect Barcode.

If you cannot find any product in the database matching the barcode, please tap on Can't find a matching item? at the bottom of the search results. Then - after you've created a new food item - connect it to the barcode following the instructions.

This means that you can either search for the correct product in order to connect it or you can create a new item yourself and connect it.