With an Apple Watch connected to the app (through the Health app), the calories that you burn on daily movement will be added to the app as exercise, increasing your caloric budget for the day. The problem is that the app also increases your caloric budget based on the activity level selected on your profile, therefore you will be double-counting burned calories on daily activity.
How to solve this? It is recommended to set your profile activity level to “Low” if you have an Apple Watch connected. That way, the app will not increase your caloric budget and it will only increase with the calories burned imported from your Apple Watch.