Does blending food raise its glycemic index

Yes.: Blenderizing food breaks down cell walls and causes the straches or sugars to be quickly absorbed, increasing glycemic index. Example from low to high: apple with peel; apple sauce; apple juice.

Not really: If you blend foods and keep the fiber in them- the glycemic index should remain the same. The stomach churns the food almost as well. Many people who blend foods, strain them and take out the fiber, the pulp, the seeds. These sources of fiber when removed, would increase the glycemic index and glycemic load delivered to the body.