Suddenly, everyone from celebrities like Kelly Ripa and ultra-marathoner Dean Karnazes to my mother-in-law seems to be sporting a fitness band. The Fitbit, Jawbone Up and Nike Fuelband are part of a booming weight-loss industry, and they've helped many Americans track their steps taken and calories consumed each day to take the guess work out of losing weight.

But some wearers are experiencing fitness band frustration. They find that their Fitbit actually moves the scale in the wrong direction—making them pack on the pounds, as opposed to maintaining or shedding unwanted weight.