You can have your calorie goal automatically adjust based on "Active Energy Burned" data that's available from the Health app. This metric is equivalent to the Move ring on an Apple Watch.
Enable the "Adjust By Amount Energy Burned" setting from the goal's setting screen (see "How do I create and edit goals?").
Active energy data is pulled from the Health app periodically, so you may observe a small delay between what the Health app and FoodNoms.
Future versions of FoodNoms may enable more options and functionality for using fitness data. Until then, please note the following limitations: