What is HealthKit and how does it work with MyFitnessPal?
HealthKit is a feature of Apple’s iOS, that was introduced with iOS 8. HealthKit manages the syncing of health and fitness data between apps, including MyFitnessPal (iPhone only) and Apple’s own app, “Health.”
To learn how to integrate MyFitnessPal with HealthKit, please see this article.
Once MyFitnessPal and HealthKit are linked, MyFitnessPal and HealthKit will (with your permission) share these types of data:
Food - MyFitnessPal will update Meal Summaries (calories and nutrients) to HealthKit.
Exercises - Exercises that are logged in HealthKit by other apps will adjust your calorie goal in MyFitnessPal. Activity added manually by the user to HealthKit does not sync to MyFitnessPal. If you have an integration partner synced with both MyFitnessPal AND HealthKit, MyFitnessPal will de-duplicate any logged exercise from that partner. Exercise simultaneously tracked by more than one app, however, will cause duplicates.
Weight - MyFitnessPal and HealthKit will update weight in both directions
You are always in control of which types of data are shared between MyFitnessPal and HealthKit. For information about adjusting these settings, please see this article.
IMPORTANT NOTE FOR MYFITNESSPAL USERS WHO LOG IN ON THE SAME IOS DEVICE
Apple's HealthKit does not distinguish between multiple accounts used in the same app on the same device. This is a limitation of HealthKit for which there is currently no solution. If you share the MyFitnessPal app on your iOS device with others by logging in and out of multiple accounts, we do not recommend linking MyFitnessPal with HealthKit at this time. If you do, data from one MyFitnessPal account may overwrite existing data in HealthKit, and vice versa, resulting in mingled data in your individual MyFitnessPal accounts.