Most flour products (bread, pasta, crackers, cake) are produced with enriched flour. The enrichment process strips most of the natural vitamins and minerals.....bran, germ and well over half of the vitamins B1, B2, B3, E, folic acid, calcium, phosphorus, zinc, copper, iron and fiber.
Sugar Busters (the book) goes so far as to claim that consuming enriched flour (i.e. a piece of white bread) is essentially comparable to eating a candy bar. As a starch, the consumption of causes a large and rapid rise in your blood sugar. For the same reason, white potatoes and corn are even restricted on a pure Sugar Busters diet. On the other hand, in the case of whole grains, the starch is broken down into sugar slowly and/or not at all. Another article if you'd like to better understand the science behind complex carbohydrates.
Thus, if you are going to consume flour products, the first ingredient must be WHOLE wheat flour. And I once again stress the word WHOLE. Wheat flour doesn't cut it.
Further research reveals that Subway does not offer a WHOLE wheat option (ingredient list). Nonetheless, I still eat at Subway often as it is a much healthier option than fast-food. I would suggest their basic 9 Grain Wheat (enriched wheat flour).
Bonus Note: Sugar Busters also ranks Rye and Sourdough up there with Whole Wheat with regard to its impact on your blood sugar. I have read, but not seen, that particular Subway's offer sourdough as an option!
When baking, many nutritionists encourage the replacement of 1/2 of the flour with whole wheat flour. I usually replace ALL of the flour with whole wheat flour and have noticed little difference in taste....even with my mother's famous coffee cake recipe!
Bonus Note: Oil can be replaced with yogurt, or applesauce! And I recently read in a magazine that you can replace the flour in brownies with pureed black beans!
In sum, when purchasing bread, crackers, pasta, etc., pay attention to the ingredients and ensure that the first ingredient is whole wheat flour.
