i think your supposed to lose power when you take your foot off the pedal, but the lack of response when you put it back on is an issue. Do you have a check engine light? doe the engine sound like its running smoothly and accelerating, but the car does not move? is it a manual or auto? This sounds like a fuel issue, if the only thing that will fix it is restarting, and only this one post as a description, i am going to guess fuel pump relay first. After clarification, i will probably change my mind.