Try replacing some (or all) of the all-purpose flour with whole-wheat flour, whole-wheat pastry flour and/or oats. If you are used to the taste and texture of whole-wheat, some cookies are just as satisfying when made with 100% whole-wheat flour. Using whole-wheat flour in place of all-purpose flour gives your cookies about four times the amount of fiber in every batch.
For more delicate-textured cookies or if you are still getting used to the taste and texture of whole-wheat, try using more finely milled whole-wheat pastry flour or mild-flavored white whole-wheat flour in place of about half of the all-purpose flour—you’ll still get the added benefit of extra fiber without much wheaty flavor.
Or try replacing 1/4 to 1/2 cup of the all-purpose flour with whole rolled oats or oats that have been ground into a “flour.”
Ground flaxseeds or flaxmeal can help add fiber to baked goods. Ground flaxseeds also contain alpha-linolenic acid (ALA), an omega-3 fatty acid linked to cardiovascular health. Try adding 2 to 4 tablespoons of ground flaxseeds (or flaxmeal) to a batch of cookies. The flavor of flax complements oat-based cookies or cookies that are highly spiced, such as ginger molasses cookies or snickerdoodles.