There are two things to check to ensure you can view barcode data.  

1. When you open KidneyDiet, and see that you are in the Daily Diary, you will notice three bars in upper left corner.

Select the bars to open the FlyOut Menu.

2. Tap on the settings.

3 & 4. Ensure toggle for USDAB Data is turned to the on position.

Or If that doesn’t solve the issue, then go to Settings on your iPhone and follow these two further steps.

5. Check the camera settings within the iPhone settings. 

6. Ensure toggle for Scan QR Codes is turned to the on position.