Fitbit flex users?

If you are planning to wear it the vast majority of the time and plan to have it sync throughout the day, I recommend enabling negative adjustments on this site to reflect activity as it relates to calorie intake.

Fitbit will also guess at activity level a bit optimistically when using cardio machines like treadmills/ellipticals- I enter the times started/ended and an estimate of how many calories burned and let it carry over from MFP instead of relying on the Fitbits perceived steps, and only rely on the calculations of the Fitbit to reflect my activity when I am NOT working out. This is useful for me because I work in an office and my +/- hour and a half in the gym is only a small part of my day.