Originally Posted by mr_pedro

In order to loose weight you should go fast and for long rides. And in order to keep that up you need the high cadence around the 90 rpm like suggested before. A low cadence may feel like your legs are working harder, and in fact they are, but for less time so power output is the same if the speed is the same no matter what the cadence is. Result of low cadence/"hard press" is that your legs burn up, making you go slower, which is bad for weight loss.