Kara, I recently made this recipe
using the whole wheat instructions. I did it twice. The first time, I was a bit scared of the bread not rising without the sugar, so I did this:
1/2 cup warm water
tsp. sugar [used real sugar]
1 packet (2-1/2 tsp.) yeast
3 c. flour
1/4 cup plus a few Tbsp sugar [Used 1/8 cup splenda, 1/8 cup erythritol, and 2 Tbsp real sugar]
1/3 cup vegetable oil
1/4 cup water
The bread turned out fine, but I found myself addicted and slightly jittery.
When I made the second batch, I still used the tsp. of sugar, but I used substitutes for the rest. It worked just as well as the first time, but I wasn't jittery and I was able to control my portion size.
Moral of the story: you may need a little sugar (though agave nectar or maple syrup could work for that) to get the yeast going, but you don't need much.
At least, that's my take on it.