Using a wearable fitness tracker may not automatically put you on the path to losing weight. Those who used such a device actually lost less weight in research discussed by Gretchen Reynolds of the New York Times as noted in the article below.
As a user of a wearable fitness tracker, this author wonders: would this study have been more useful if the researchers had replicated real-world use? The devices were worn around the upper arm by one group of participants in the study. Many users wear the fitness tracker on the wrist. Easy viewing of steps taken and other data serves as a motivator.