Outback Steakhouse doesn't unveil the recipe for their bread, but Copycat Version of Outback Steakhouse Bread Recipe lists     Ingredients         3 packages dry yeast   1 1/2 cups warm water (divided)   1 tablespoon sugar   1/2 cup dark molasses   1 tablespoon salt   2 tablespoons neutral oil (vegetable or canola)   2 cups rye flour   2 1/2 to 3 cups all-purpose flour      What happens if I must eschew the sugar and molasses for medical reasons? I don't care if the color changes.   
Under- or over-proofed bread will change the "crumb" of the bread but has nothing to do with food safety. If it is baked fully it will be safe even if it's a little dense or too airy.  