White bread has a glycemic index of 75; table sugar is 65. Refined grains spike blood sugar faster than sugar itself because milling removes fiber, bran, and germ, leaving pure starch that converts rapidly to glucose. The rapid spike triggers a correspondingly large insulin response.
This companion explores the glycemic index surprise, why this happens mechanically, the insulin response pattern, what “complex carbohydrates” actually means, and practical implications for choosing foods. (4 min read)