Does doing the "30 Day Shred" 2X a day speed up results?

I have recently started doing the 30 Day Shred, but missed doing it yesterday. I have already done it once this morning. If I do it again tonight, will that make up for the missed day?

P.S. If you are at a healthy weight with a tiny bit of belly fat, is doing this exercise along with a healthy diet enough to eliminate the belly fat?