What is the "Fitbit Calorie Adjustment" in my exercise diary?
When the data reported by your Fitbit account shows that your daily calorie prediction from Fitbit and your estimated daily calories from your MyFitnessPal account are different, we'll adjust your net calorie goal accordingly. The "Fitbit Calorie Adjustment" represents the additional calories you have burned, above and beyond our original estimate. You may also see a negative adjustment if your activity level suggests you are less active than our MyFitnessPal estimate assumes. Details about the calculation of any adjustment can be viewed by clicking the small "i" next to the adjustment in your Exercise Diary (on the full website). Because the adjustment value is recalculated every time your Fitbit uploads new data, you should expect this value to change over the course of the day.
By default, MyFitnessPal will show you only positive calorie adjustments. To permit negative adjustments, log in to the full MyFitnessPal site at http://www.myfitnesspal.com and click "My Home" then "Settings" then "Diary Settings." Check the box for "Enable Negative Adjustments" then click "Save Changes."
If you are typically unable to sync your device until late in the day, you may wish to leave negative adjustments "off."