A few months ago I read about resistant starch in the Environmental Nutrition journal, so-called because it resists digestion in the small intestine. Why is that good, you might ask. It's good because the small intestine is most of your digestion takes place. It's where carbohydrates are turned into glucose. If you are consuming large amounts of refined carbs your small intestine is dumping a lot of glucose into your blood, which of course jacks up your blood glucose level. This is turn jacks up your insulin level, which makes you hungry for more carbs and also triggers the packing on of belly fat and probably, untimately obesity. A combination of obesity and a sedentary lifestyle leads to insulin resistance, which means excess glucose damaging your organs, and then diabetes if the cycle isn't broken. Read The New Glucose Revolution for a more indepth discussion.
Back to resistant starch - when you substitute part of the flour in baked goods with resistant starch you effectively slow down the digestion of those carbohydrates. Go to http://www.resistantstarch.com/ResistantStarch/ for wealth of information on what it means to your health. There is evidence that it may help you burn fat, regulate blood glucose levels, feed the good bacteria in your gut, and more.
Resistant starch occurs naturally in foods such as beans and grains. It is available for cooking and baking as Natural HiMaize, a cornstarch which is low in calories and extremely high in fiber. I personally have substituted up to 30% of the flour in my bread recipes with excellent results. I buy if from Honeyville
Grain in 5 lb. bags because I bake a lot and it's more cost effective. It's also available from King
Arthur Flour in 10 oz. bags so you can just stick your toe in.
Here's my Potato Gnocchi recipe to get you started. I substituted in 1/3 Hi-Maize with great results. Absolutely delicious!