Whole grains are a great source of important nutrients; protein, fiber, vitamins, minerals, and, especially, carbohydrates that are low on the glycemic index (GI). Glycemic Index is an indication of how a carbohydrate will affect your blood sugar. For many people eating a lot of foods that are high in GI will produce blood sugar spikes that can eventually lead to insulin resistance. Signs of insulin resistance are obesity, high blood pressure, high triglycerides, type 2 diabetes, and other diseases.
Grains naturally have a low glycemic index if they have not been processed. Processed carbohydrates have a high GI. It takes longer to digest whole grains because your body has to break them down, this takes time.
When grains are made into flour it makes it really easy for the body to digest them, it doesn't make a difference whether they are whole grain or not. You have pre-digested them by grinding them and have made them really easy for the body to work on quickly and absorb. While eating whole grains is good for you, you want to avoid eating whole grain flour products because they will affect your blood sugar due to the high GI.
Eat whole, whole grains not ground or powdered whole grains (read flour). Oatmeal is very popular with some people, but there is a vast difference between steel cut oats that take 40 minutes to cook and instant oatmeal (pulverized) that you only have to add hot water to and stir, or even the oatmeal served at McDonald's that has as much sugar as a Snickers Bar, check this story out: http://abcnews.go.com/US/
The following whole grains (this not a comprehensive list but you should be able to find them) are healthy and lower in GI in their natural state. You also have to keep quantity in mind you don't want to sit around and eat a ton of brown rice or a ton of anything else for that matter, they are still carbohydrates:
- Amaranth
- Barley
- Brown rice
- Bulgur (cracked wheat)
- Flaxseed
- Millet
- Oats
- Quinoa
- Rye
- Spelt
- Wheat berries
- Wild rice
