Autumn
Hi Marion,
Sure, you can eat brown bread on macrobiotics depending on the result you want.
Macrobiotics is simply about eating for your life dream. There are days when brown bread is a great option (ie, you're at a party and the only other option is cheesecake). The real art of MB is taking your situation, thinking about your direction with clarity, and then steering through the best choice that you have from moment to moment. There's no one diet; it's just that over generations, we've discovered that most people tend toward the same goals (to be limber, or alert in the morning, or sleep well at night) so the diet has developed some general recommendations.
Georges Ohsawa was an interesting man, but just my personal vote is that his books have historic and nostalgic value, but are not good as a teaching text for beginners. They're better for long-term practitioners who enjoy reading the historic train of thought that created the movement.
If you are going to do MB, I'd recommend reading and studying a lot first, and trying to find long-term people to eat and cook with and ideally a good counselor. Is that possible in your area?
Take care,
A